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• CodePlex Daily Summary for Sunday, June 01, 2014

  CodePlex Daily Summary for Sunday, June 01, 2014Popular ReleasesSandcastle Help File Builder: Help File Builder and Tools v2014.5.31.0: General InformationIMPORTANT: On some systems, the content of the ZIP file is blocked and the installer may fail to run. Before extracting it, right click on the ZIP file, select Properties, and click on the Unblock button if it is present in the lower right corner of the General tab in the properties dialog. This release completes removal of the branding transformations and implements the new VS2013 presentation style that utilizes the new lightweight website format. Several breaking cha...Tooltip Web Preview: ToolTip Web Preview: Version 1.0Database Helper: Release 1.0.0.0: First Release of Database HelperCoMaSy: CoMaSy1.0.2: !Contact Management SystemImage View Slider: Image View Slider: This is a .NET component. We create this using VB.NET. Here you can use an Image Viewer with several properties to your application form. We wish somebody to improve freely. Try this out! Author : Steven Renaldo Antony Yustinus Arjuna Purnama Putra Andre Wijaya P Martin Lidau PBK GENAP 2014 - TI UKDWAspose for Apache POI: Missing Features of Apache POI WP - v 1.1: Release contain the Missing Features in Apache POI WP SDK in Comparison with Aspose.Words for dealing with Microsoft Word. What's New ?Following Examples: Insert Picture in Word Document Insert Comments Set Page Borders Mail Merge from XML Data Source Moving the Cursor Feedback and Suggestions Many more examples are yet to come here. Keep visiting us. Raise your queries and suggest more examples via Aspose Forums or via this social coding site.babelua: V1.5.6.0: V1.5.6.0 - 2014.5.30New feature: support quick-cocos2d-x project now; support text search in scripts folder now, you can use this function in Search Result Window;SEToolbox: 01.032.014 Release 1: Added fix when loading game Textures for icons causing 'Unable to read beyond the end of the stream'. Added new Resource Report, that displays all in game resources in a concise report. Added in temp directory cleaner, to keep excess files from building up. Fixed use of colors on the windows, to work better with desktop schemes. Adding base support for multilingual resources. This will allow loading of the Space Engineers resources to show localized names, and display localized date a...ClosedXML - The easy way to OpenXML: ClosedXML 0.71.2: More memory and performance improvements. Fixed an issue with pivot table field order.Fancontroller: Fancontroller: Initial releaseVi-AIO SearchBar: Vi – AIO Search Bar: Version 1.0Top Verses ( Ayat Emas ): Binary Top Verses: This one is the bin folder of the component. the .dll component is inside.Traditional Calendar Component: Traditional Calender Converter: Duta Wacana Christian University This file containing Traditional Calendar Component and Demo Aplication that using Traditional Calendar Component. This component made with .NET Framework 4 and the programming language is C# .SQLSetupHelper: 1.0.0.0: First Stable Version of SQL SetupComposite Iconote: Composite Iconote: This is a composite has been made by Microsoft Visual Studio 2013. Requirement: To develop this composite or use this component in your application, your computer must have .NET framework 4.5 or newer.Magick.NET: Magick.NET 6.8.9.101: Magick.NET linked with ImageMagick 6.8.9.1. Breaking changes: - Int/short Set methods of WritablePixelCollection are now unsigned. - The Q16 build no longer uses HDRI, switch to the new Q16-HDRI build if you need HDRI.fnr.exe - Find And Replace Tool: 1.7: Bug fixes Refactored logic for encoding text values to command line to handle common edge cases where find/replace operation works in GUI but not in command line Fix for bug where selection in Encoding drop down was different when generating command line in some cases. It was reported in: https://findandreplace.codeplex.com/workitem/34 Fix for "Backslash inserted before dot in replacement text" reported here: https://findandreplace.codeplex.com/discussions/541024 Fix for finding replacing...VG-Ripper & PG-Ripper: VG-Ripper 2.9.59: changes NEW: Added Support for 'GokoImage.com' links NEW: Added Support for 'ViperII.com' links NEW: Added Support for 'PixxxView.com' links NEW: Added Support for 'ImgRex.com' links NEW: Added Support for 'PixLiv.com' links NEW: Added Support for 'imgsee.me' links NEW: Added Support for 'ImgS.it' linksToolbox for Dynamics CRM 2011/2013: XrmToolBox (v1.2014.5.28): XrmToolbox improvement XrmToolBox updates (v1.2014.5.28)Fix connecting to a connection with custom authentication without saved password Tools improvement New tool!Solution Components Mover (v1.2014.5.22) Transfer solution components from one solution to another one Import/Export NN relationships (v1.2014.3.7) Allows you to import and export many to many relationships Tools updatesAttribute Bulk Updater (v1.2014.5.28) Audit Center (v1.2014.5.28) View Layout Replicator (v1.2014.5.28) Scrip...Microsoft Ajax Minifier: Microsoft Ajax Minifier 5.10: Fix for Issue #20875 - echo switch doesn't work for CSS CSS should honor the SASS source-file comments JS should allow multi-line comment directivesNew ProjectsCet MicroWPF: WPF-like library for simple graphic-UI application using Netduino (Plus) 2 and the FTDI FT800 Eve board.Fakemons: Some Fakmons, powered by XML, XSLT, CSS and JavascriptFling OS: Fling OS is a C# operating system project aiming to create a new, managed operating system from the ground up.MudRoom: Experimental tool sets in mud parsing and area definitionOOP-2112110158: My name's NgocDungRoslynResearch: Roslyn ResearchTHD - Control de Usuarios: control de usuarios y permisosWPF Kinect User Controls: WPF Kinect User Control project provide simple Tilt and Skeleton Tracking Parameter Controls.

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• How to free up space on /boot? [closed]

  - by Phrogz

  Possible Duplicate: Free up more space on /boot I logged onto my server today to find the message: => /boot is using 98.9% of 91MB When I look at /boot I see that it is indeed very low on space, and has old-kernel files in it: phrogz@planar:~$ df -h /boot Filesystem Size Used Avail Use% Mounted on /dev/sda1 92M 54M 33M 63% /boot phrogz@planar:~$ la /boot total 81880 drwxr-xr-x 4 root root 3072 2011-12-02 06:26 ./ drwxr-xr-x 22 root root 4096 2011-09-29 06:37 ../ -rw-r--r-- 1 root root 646419 2011-03-01 19:02 abi-2.6.32-30-server -rw-r--r-- 1 root root 646419 2011-04-08 17:07 abi-2.6.32-31-server -rw-r--r-- 1 root root 646454 2011-04-20 16:53 abi-2.6.32-32-server -rw-r--r-- 1 root root 646454 2011-07-29 16:07 abi-2.6.32-33-server -rw-r--r-- 1 root root 646710 2011-09-13 18:00 abi-2.6.32-34-server -rw-r--r-- 1 root root 646820 2011-10-11 11:10 abi-2.6.32-35-server -rw-r--r-- 1 root root 110687 2011-03-01 19:02 config-2.6.32-30-server -rw-r--r-- 1 root root 110676 2011-04-08 17:07 config-2.6.32-31-server -rw-r--r-- 1 root root 110687 2011-04-20 16:53 config-2.6.32-32-server -rw-r--r-- 1 root root 110687 2011-07-29 16:07 config-2.6.32-33-server -rw-r--r-- 1 root root 110687 2011-09-13 18:00 config-2.6.32-34-server -rw-r--r-- 1 root root 110687 2011-10-11 11:10 config-2.6.32-35-server drwxr-xr-x 3 root root 6144 2011-12-02 06:26 grub/ -rw-r--r-- 1 root root 8258196 2011-05-18 11:58 initrd.img-2.6.32-30-server -rw-r--r-- 1 root root 8259568 2011-05-23 20:24 initrd.img-2.6.32-31-server -rw-r--r-- 1 root root 8257374 2011-05-30 07:47 initrd.img-2.6.32-32-server -rw-r--r-- 1 root root 8287489 2011-08-10 06:37 initrd.img-2.6.32-33-server -rw-r--r-- 1 root root 8288075 2011-09-29 06:37 initrd.img-2.6.32-34-server drwx------ 2 root root 12288 2011-05-18 11:46 lost+found/ -rw-r--r-- 1 root root 160280 2010-03-23 03:40 memtest86+.bin -rw-r--r-- 1 root root 2179117 2011-03-01 19:02 System.map-2.6.32-30-server -rw-r--r-- 1 root root 2179628 2011-04-08 17:07 System.map-2.6.32-31-server -rw-r--r-- 1 root root 2178240 2011-04-20 16:53 System.map-2.6.32-32-server -rw-r--r-- 1 root root 2178382 2011-07-29 16:07 System.map-2.6.32-33-server -rw-r--r-- 1 root root 2178952 2011-09-13 18:00 System.map-2.6.32-34-server -rw-r--r-- 1 root root 2179333 2011-10-11 11:10 System.map-2.6.32-35-server -rw-r--r-- 1 root root 1336 2011-03-01 19:08 vmcoreinfo-2.6.32-30-server -rw-r--r-- 1 root root 1336 2011-04-08 17:13 vmcoreinfo-2.6.32-31-server -rw-r--r-- 1 root root 1336 2011-04-20 16:54 vmcoreinfo-2.6.32-32-server -rw-r--r-- 1 root root 1336 2011-07-29 16:08 vmcoreinfo-2.6.32-33-server -rw-r--r-- 1 root root 1336 2011-09-13 18:03 vmcoreinfo-2.6.32-34-server -rw-r--r-- 1 root root 1336 2011-10-11 11:11 vmcoreinfo-2.6.32-35-server -rw-r--r-- 1 root root 4111552 2011-03-01 19:02 vmlinuz-2.6.32-30-server -rw-r--r-- 1 root root 4113344 2011-04-08 17:07 vmlinuz-2.6.32-31-server -rw-r--r-- 1 root root 4106528 2011-04-20 16:53 vmlinuz-2.6.32-32-server -rw-r--r-- 1 root root 4107648 2011-07-29 16:07 vmlinuz-2.6.32-33-server -rw-r--r-- 1 root root 4108960 2011-09-13 18:00 vmlinuz-2.6.32-34-server -rw-r--r-- 1 root root 4111040 2011-10-11 11:10 vmlinuz-2.6.32-35-server I was able to find the old kernel packages like so: phrogz@planar:/boot$ dpkg -l | grep linux-image ii linux-image-2.6.32-30-server 2.6.32-30.59 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-31-server 2.6.32-31.61 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-32-server 2.6.32-32.62 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-33-server 2.6.32-33.72 Linux kernel image for version 2.6.32 on x86 ii linux-image-2.6.32-34-server 2.6.32-34.77 Linux kernel image for version 2.6.32 on x86 iF linux-image-2.6.32-35-server 2.6.32-35.78 Linux kernel image for version 2.6.32 on x86 iU linux-image-server 2.6.32.36.42 Linux kernel image on Server Equipment. …and I can see that many of them are older than my current image: phrogz@planar:/boot$ uname -a Linux planar 2.6.32-34-server #77-Ubuntu SMP Tue Sep 13 20:54:38 UTC 2011 x86_64 GNU/Linux However, I can't actually remove them due to an unmet dependency: phrogz@planar:/boot$ sudo apt-get --purge remove linux-image-2.6.32-30-server Reading package lists... Done Building dependency tree Reading state information... Done You might want to run `apt-get -f install' to correct these: The following packages have unmet dependencies: linux-image-server: Depends: linux-image-2.6.32-36-server but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). But I can't fix the dependency (presumably due to low disk space): phrogz@planar:/boot$ sudo apt-get -f install Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required: liblcms1 linux-headers-2.6.32-32-server libnspr4-0d linux-headers-2.6.32-33-server linux-headers-2.6.32-32 linux-headers-2.6.32-33 linux-headers-2.6.32-34 libcups2 tzdata-java libjpeg62 linux-headers-2.6.32-34-server libavahi-client3 ca-certificates-java libnss3-1d Use 'apt-get autoremove' to remove them. The following extra packages will be installed: linux-image-2.6.32-36-server Suggested packages: fdutils linux-doc-2.6.32 linux-source-2.6.32 linux-tools The following NEW packages will be installed: linux-image-2.6.32-36-server 0 upgraded, 1 newly installed, 0 to remove and 8 not upgraded. 3 not fully installed or removed. Need to get 0B/31.8MB of archives. After this operation, 128MB of additional disk space will be used. Do you want to continue [Y/n]? (Reading database ... 145200 files and directories currently installed.) Unpacking linux-image-2.6.32-36-server (from .../linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb) ... Done. dpkg: error processing /var/cache/apt/archives/linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb (--unpack): failed in buffer_write(fd) (10, ret=-1): backend dpkg-deb during `./boot/vmlinuz-2.6.32-36-server': No space left on device dpkg-deb: subprocess paste killed by signal (Broken pipe) Running postrm hook script /usr/sbin/update-grub. Generating grub.cfg ... Found linux image: /boot/vmlinuz-2.6.32-35-server Found linux image: /boot/vmlinuz-2.6.32-34-server Found initrd image: /boot/initrd.img-2.6.32-34-server Found linux image: /boot/vmlinuz-2.6.32-33-server Found initrd image: /boot/initrd.img-2.6.32-33-server Found linux image: /boot/vmlinuz-2.6.32-32-server Found initrd image: /boot/initrd.img-2.6.32-32-server Found linux image: /boot/vmlinuz-2.6.32-31-server Found initrd image: /boot/initrd.img-2.6.32-31-server Found linux image: /boot/vmlinuz-2.6.32-30-server Found initrd image: /boot/initrd.img-2.6.32-30-server Found memtest86+ image: /memtest86+.bin done Errors were encountered while processing: /var/cache/apt/archives/linux-image-2.6.32-36-server_2.6.32-36.79_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1) How do I free up space on /boot so that I can fix my dependencies? Should I just delete the files manually? And then, should I resize my /boot to be larger, so this doesn't happen again? If so, how? If not, what maintenance should I be running regularly to prevent the accumulation of this cruft?

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• SortedDictionary and SortedList

  - by Simon Cooper

  Apart from Dictionary<TKey, TValue>, there's two other dictionaries in the BCL - SortedDictionary<TKey, TValue> and SortedList<TKey, TValue>. On the face of it, these two classes do the same thing - provide an IDictionary<TKey, TValue> interface where the iterator returns the items sorted by the key. So what's the difference between them, and when should you use one rather than the other? (as in my previous post, I'll assume you have some basic algorithm & datastructure knowledge) SortedDictionary We'll first cover SortedDictionary. This is implemented as a special sort of binary tree called a red-black tree. Essentially, it's a binary tree that uses various constraints on how the nodes of the tree can be arranged to ensure the tree is always roughly balanced (for more gory algorithmical details, see the wikipedia link above). What I'm concerned about in this post is how the .NET SortedDictionary is actually implemented. In .NET 4, behind the scenes, the actual implementation of the tree is delegated to a SortedSet<KeyValuePair<TKey, TValue>>. One example tree might look like this: Each node in the above tree is stored as a separate SortedSet<T>.Node object (remember, in a SortedDictionary, T is instantiated to KeyValuePair<TKey, TValue>): class Node { public bool IsRed; public T Item; public SortedSet<T>.Node Left; public SortedSet<T>.Node Right; } The SortedSet only stores a reference to the root node; all the data in the tree is accessed by traversing the Left and Right node references until you reach the node you're looking for. Each individual node can be physically stored anywhere in memory; what's important is the relationship between the nodes. This is also why there is no constructor to SortedDictionary or SortedSet that takes an integer representing the capacity; there are no internal arrays that need to be created and resized. This may seen trivial, but it's an important distinction between SortedDictionary and SortedList that I'll cover later on. And that's pretty much it; it's a standard red-black tree. Plenty of webpages and datastructure books cover the algorithms behind the tree itself far better than I could. What's interesting is the comparions between SortedDictionary and SortedList, which I'll cover at the end. As a side point, SortedDictionary has existed in the BCL ever since .NET 2. That means that, all through .NET 2, 3, and 3.5, there has been a bona-fide sorted set class in the BCL (called TreeSet). However, it was internal, so it couldn't be used outside System.dll. Only in .NET 4 was this class exposed as SortedSet. SortedList Whereas SortedDictionary didn't use any backing arrays, SortedList does. It is implemented just as the name suggests; two arrays, one containing the keys, and one the values (I've just used random letters for the values): The items in the keys array are always guarenteed to be stored in sorted order, and the value corresponding to each key is stored in the same index as the key in the values array. In this example, the value for key item 5 is 'z', and for key item 8 is 'm'. Whenever an item is inserted or removed from the SortedList, a binary search is run on the keys array to find the correct index, then all the items in the arrays are shifted to accomodate the new or removed item. For example, if the key 3 was removed, a binary search would be run to find the array index the item was at, then everything above that index would be moved down by one: and then if the key/value pair {7, 'f'} was added, a binary search would be run on the keys to find the index to insert the new item, and everything above that index would be moved up to accomodate the new item: If another item was then added, both arrays would be resized (to a length of 10) before the new item was added to the arrays. As you can see, any insertions or removals in the middle of the list require a proportion of the array contents to be moved; an O(n) operation. However, if the insertion or removal is at the end of the array (ie the largest key), then it's only O(log n); the cost of the binary search to determine it does actually need to be added to the end (excluding the occasional O(n) cost of resizing the arrays to fit more items). As a side effect of using backing arrays, SortedList offers IList Keys and Values views that simply use the backing keys or values arrays, as well as various methods utilising the array index of stored items, which SortedDictionary does not (and cannot) offer. The Comparison So, when should you use one and not the other? Well, here's the important differences: Memory usage SortedDictionary and SortedList have got very different memory profiles. SortedDictionary... has a memory overhead of one object instance, a bool, and two references per item. On 64-bit systems, this adds up to ~40 bytes, not including the stored item and the reference to it from the Node object. stores the items in separate objects that can be spread all over the heap. This helps to keep memory fragmentation low, as the individual node objects can be allocated wherever there's a spare 60 bytes. In contrast, SortedList... has no additional overhead per item (only the reference to it in the array entries), however the backing arrays can be significantly larger than you need; every time the arrays are resized they double in size. That means that if you add 513 items to a SortedList, the backing arrays will each have a length of 1024. To conteract this, the TrimExcess method resizes the arrays back down to the actual size needed, or you can simply assign list.Capacity = list.Count. stores its items in a continuous block in memory. If the list stores thousands of items, this can cause significant problems with Large Object Heap memory fragmentation as the array resizes, which SortedDictionary doesn't have. Performance Operations on a SortedDictionary always have O(log n) performance, regardless of where in the collection you're adding or removing items. In contrast, SortedList has O(n) performance when you're altering the middle of the collection. If you're adding or removing from the end (ie the largest item), then performance is O(log n), same as SortedDictionary (in practice, it will likely be slightly faster, due to the array items all being in the same area in memory, also called locality of reference). So, when should you use one and not the other? As always with these sort of things, there are no hard-and-fast rules. But generally, if you: need to access items using their index within the collection are populating the dictionary all at once from sorted data aren't adding or removing keys once it's populated then use a SortedList. But if you: don't know how many items are going to be in the dictionary are populating the dictionary from random, unsorted data are adding & removing items randomly then use a SortedDictionary. The default (again, there's no definite rules on these sort of things!) should be to use SortedDictionary, unless there's a good reason to use SortedList, due to the bad performance of SortedList when altering the middle of the collection.

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• Monitoring Html Element CSS Changes in JavaScript

  - by Rick Strahl

  [ updated Feb 15, 2011: Added event unbinding to avoid unintended recursion ] Here's a scenario I've run into on a few occasions: I need to be able to monitor certain CSS properties on an HTML element and know when that CSS element changes. For example, I have a some HTML element behavior plugins like a drop shadow that attaches to any HTML element, but I then need to be able to automatically keep the shadow in sync with the window if the  element dragged around the window or moved via code. Unfortunately there's no move event for HTML elements so you can't tell when it's location changes. So I've been looking around for some way to keep track of the element and a specific CSS property, but no luck. I suspect there's nothing native to do this so the only way I could think of is to use a timer and poll rather frequently for the property. I ended up with a generic jQuery plugin that looks like this: (function($){ $.fn.watch = function (props, func, interval, id) { /// <summary> /// Allows you to monitor changes in a specific /// CSS property of an element by polling the value. /// when the value changes a function is called. /// The function called is called in the context /// of the selected element (ie. this) /// </summary> /// <param name="prop" type="String">CSS Properties to watch sep. by commas</param> /// <param name="func" type="Function"> /// Function called when the value has changed. /// </param> /// <param name="interval" type="Number"> /// Optional interval for browsers that don't support DOMAttrModified or propertychange events. /// Determines the interval used for setInterval calls. /// </param> /// <param name="id" type="String">A unique ID that identifies this watch instance on this element</param> /// <returns type="jQuery" /> if (!interval) interval = 200; if (!id) id = "_watcher"; return this.each(function () { var _t = this; var el$ = $(this); var fnc = function () { __watcher.call(_t, id) }; var itId = null; var data = { id: id, props: props.split(","), func: func, vals: [props.split(",").length], fnc: fnc, origProps: props, interval: interval }; $.each(data.props, function (i) { data.vals[i] = el$.css(data.props[i]); }); el$.data(id, data); hookChange(el$, id, data.fnc); }); function hookChange(el$, id, fnc) { el$.each(function () { var el = $(this); if (typeof (el.get(0).onpropertychange) == "object") el.bind("propertychange." + id, fnc); else if ($.browser.mozilla) el.bind("DOMAttrModified." + id, fnc); else itId = setInterval(fnc, interval); }); } function __watcher(id) { var el$ = $(this); var w = el$.data(id); if (!w) return; var _t = this; if (!w.func) return; // must unbind or else unwanted recursion may occur el$.unwatch(id); var changed = false; var i = 0; for (i; i < w.props.length; i++) { var newVal = el$.css(w.props[i]); if (w.vals[i] != newVal) { w.vals[i] = newVal; changed = true; break; } } if (changed) w.func.call(_t, w, i); // rebind event hookChange(el$, id, w.fnc); } } $.fn.unwatch = function (id) { this.each(function () { var el = $(this); var fnc = el.data(id).fnc; try { if (typeof (this.onpropertychange) == "object") el.unbind("propertychange." + id, fnc); else if ($.browser.mozilla) el.unbind("DOMAttrModified." + id, fnc); else clearInterval(id); } // ignore if element was already unbound catch (e) { } }); return this; } })(jQuery); With this I can now monitor movement by monitoring say the top CSS property of the element. The following code creates a box and uses the draggable (jquery.ui) plugin and a couple of custom plugins that center and create a shadow. Here's how I can set this up with the watcher: $("#box") .draggable() .centerInClient() .shadow() .watch("top", function() { $(this).shadow(); },70,"_shadow"); ... $("#box") .unwatch("_shadow") .shadow("remove"); This code basically sets up the window to be draggable and initially centered and then a shadow is added. The .watch() call then assigns a CSS property to monitor (top in this case) and a function to call in response. The component now sets up a setInterval call and keeps on pinging this property every time. When the top value changes the supplied function is called. While this works and I can now drag my window around with the shadow following suit it's not perfect by a long shot. The shadow move is delayed and so drags behind the window, but using a higher timer value is not appropriate either as the UI starts getting jumpy if the timer's set with too small of an increment. This sort of monitor can be useful for other things as well where operations are maybe not quite as time critical as a UI operation taking place. Can anybody see a better a better way of capturing movement of an element on the page?© Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  JavaScript  jQuery  

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• Pluggable Rules for Entity Framework Code First

  - by Ricardo Peres

  Suppose you want a system that lets you plug custom validation rules on your Entity Framework context. The rules would control whether an entity can be saved, updated or deleted, and would be implemented in plain .NET. Yes, I know I already talked about plugable validation in Entity Framework Code First, but this is a different approach. An example API is in order, first, a ruleset, which will hold the collection of rules: 1: public interface IRuleset : IDisposable 2: { 3: void AddRule<T>(IRule<T> rule); 4: IEnumerable<IRule<T>> GetRules<T>(); 5: } Next, a rule: 1: public interface IRule<T> 2: { 3: Boolean CanSave(T entity, DbContext ctx); 4: Boolean CanUpdate(T entity, DbContext ctx); 5: Boolean CanDelete(T entity, DbContext ctx); 6: String Name 7: { 8: get; 9: } 10: } Let’s analyze what we have, starting with the ruleset: Only has methods for adding a rule, specific to an entity type, and to list all rules of this entity type; By implementing IDisposable, we allow it to be cancelled, by disposing of it when we no longer want its rules to be applied. A rule, on the other hand: Has discrete methods for checking if a given entity can be saved, updated or deleted, which receive as parameters the entity itself and a pointer to the DbContext to which the ruleset was applied; Has a name property for helping us identifying what failed. A ruleset really doesn’t need a public implementation, all we need is its interface. The private (internal) implementation might look like this: 1: sealed class Ruleset : IRuleset 2: { 3: private readonly IDictionary<Type, HashSet<Object>> rules = new Dictionary<Type, HashSet<Object>>(); 4: private ObjectContext octx = null; 5:  6: internal Ruleset(ObjectContext octx) 7: { 8: this.octx = octx; 9: } 10:  11: public void AddRule<T>(IRule<T> rule) 12: { 13: if (this.rules.ContainsKey(typeof(T)) == false) 14: { 15: this.rules[typeof(T)] = new HashSet<Object>(); 16: } 17:  18: this.rules[typeof(T)].Add(rule); 19: } 20:  21: public IEnumerable<IRule<T>> GetRules<T>() 22: { 23: if (this.rules.ContainsKey(typeof(T)) == true) 24: { 25: foreach (IRule<T> rule in this.rules[typeof(T)]) 26: { 27: yield return (rule); 28: } 29: } 30: } 31:  32: public void Dispose() 33: { 34: this.octx.SavingChanges -= RulesExtensions.OnSaving; 35: RulesExtensions.rulesets.Remove(this.octx); 36: this.octx = null; 37:  38: this.rules.Clear(); 39: } 40: } Basically, this implementation: Stores the ObjectContext of the DbContext to which it was created for, this is so that later we can remove the association; Has a collection - a set, actually, which does not allow duplication - of rules indexed by the real Type of an entity (because of proxying, an entity may be of a type that inherits from the class that we declared); Has generic methods for adding and enumerating rules of a given type; Has a Dispose method for cancelling the enforcement of the rules. A (really dumb) rule applied to Product might look like this: 1: class ProductRule : IRule<Product> 2: { 3: #region IRule<Product> Members 4:  5: public String Name 6: { 7: get 8: { 9: return ("Rule 1"); 10: } 11: } 12:  13: public Boolean CanSave(Product entity, DbContext ctx) 14: { 15: return (entity.Price > 10000); 16: } 17:  18: public Boolean CanUpdate(Product entity, DbContext ctx) 19: { 20: return (true); 21: } 22:  23: public Boolean CanDelete(Product entity, DbContext ctx) 24: { 25: return (true); 26: } 27:  28: #endregion 29: } The DbContext is there because we may need to check something else in the database before deciding whether to allow an operation or not. And here’s how to apply this mechanism to any DbContext, without requiring the usage of a subclass, by means of an extension method: 1: public static class RulesExtensions 2: { 3: private static readonly MethodInfo getRulesMethod = typeof(IRuleset).GetMethod("GetRules"); 4: internal static readonly IDictionary<ObjectContext, Tuple<IRuleset, DbContext>> rulesets = new Dictionary<ObjectContext, Tuple<IRuleset, DbContext>>(); 5:  6: private static Type GetRealType(Object entity) 7: { 8: return (entity.GetType().Assembly.IsDynamic == true ? entity.GetType().BaseType : entity.GetType()); 9: } 10:  11: internal static void OnSaving(Object sender, EventArgs e) 12: { 13: ObjectContext octx = sender as ObjectContext; 14: IRuleset ruleset = rulesets[octx].Item1; 15: DbContext ctx = rulesets[octx].Item2; 16:  17: foreach (ObjectStateEntry entry in octx.ObjectStateManager.GetObjectStateEntries(EntityState.Added)) 18: { 19: Object entity = entry.Entity; 20: Type realType = GetRealType(entity); 21:  22: foreach (dynamic rule in (getRulesMethod.MakeGenericMethod(realType).Invoke(ruleset, null) as IEnumerable)) 23: { 24: if (rule.CanSave(entity, ctx) == false) 25: { 26: throw (new Exception(String.Format("Cannot save entity {0} due to rule {1}", entity, rule.Name))); 27: } 28: } 29: } 30:  31: foreach (ObjectStateEntry entry in octx.ObjectStateManager.GetObjectStateEntries(EntityState.Deleted)) 32: { 33: Object entity = entry.Entity; 34: Type realType = GetRealType(entity); 35:  36: foreach (dynamic rule in (getRulesMethod.MakeGenericMethod(realType).Invoke(ruleset, null) as IEnumerable)) 37: { 38: if (rule.CanDelete(entity, ctx) == false) 39: { 40: throw (new Exception(String.Format("Cannot delete entity {0} due to rule {1}", entity, rule.Name))); 41: } 42: } 43: } 44:  45: foreach (ObjectStateEntry entry in octx.ObjectStateManager.GetObjectStateEntries(EntityState.Modified)) 46: { 47: Object entity = entry.Entity; 48: Type realType = GetRealType(entity); 49:  50: foreach (dynamic rule in (getRulesMethod.MakeGenericMethod(realType).Invoke(ruleset, null) as IEnumerable)) 51: { 52: if (rule.CanUpdate(entity, ctx) == false) 53: { 54: throw (new Exception(String.Format("Cannot update entity {0} due to rule {1}", entity, rule.Name))); 55: } 56: } 57: } 58: } 59:  60: public static IRuleset CreateRuleset(this DbContext context) 61: { 62: Tuple<IRuleset, DbContext> ruleset = null; 63: ObjectContext octx = (context as IObjectContextAdapter).ObjectContext; 64:  65: if (rulesets.TryGetValue(octx, out ruleset) == false) 66: { 67: ruleset = rulesets[octx] = new Tuple<IRuleset, DbContext>(new Ruleset(octx), context); 68: 69: octx.SavingChanges += OnSaving; 70: } 71:  72: return (ruleset.Item1); 73: } 74: } It relies on the SavingChanges event of the ObjectContext to intercept the saving operations before they are actually issued. Yes, it uses a bit of dynamic magic! Very handy, by the way! So, let’s put it all together: 1: using (MyContext ctx = new MyContext()) 2: { 3: IRuleset rules = ctx.CreateRuleset(); 4: rules.AddRule(new ProductRule()); 5:  6: ctx.Products.Add(new Product() { Name = "xyz", Price = 50000 }); 7:  8: ctx.SaveChanges(); //an exception is fired here 9:  10: //when we no longer need to apply the rules 11: rules.Dispose(); 12: } Feel free to use it and extend it any way you like, and do give me your feedback! As a final note, this can be easily changed to support plain old Entity Framework (not Code First, that is), if that is what you are using.

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• SQL SERVER – SSIS Look Up Component – Cache Mode – Notes from the Field #028

  - by Pinal Dave

  [Notes from Pinal]: Lots of people think that SSIS is all about arranging various operations together in one logical flow. Well, the understanding is absolutely correct, but the implementation of the same is not as easy as it seems. Similarly most of the people think lookup component is just component which does look up for additional information and does not pay much attention to it. Due to the same reason they do not pay attention to the same and eventually get very bad performance. Linchpin People are database coaches and wellness experts for a data driven world. In this 28th episode of the Notes from the Fields series database expert Tim Mitchell (partner at Linchpin People) shares very interesting conversation related to how to write a good lookup component with Cache Mode. In SQL Server Integration Services, the lookup component is one of the most frequently used tools for data validation and completion.  The lookup component is provided as a means to virtually join one set of data to another to validate and/or retrieve missing values.  Properly configured, it is reliable and reasonably fast. Among the many settings available on the lookup component, one of the most critical is the cache mode.  This selection will determine whether and how the distinct lookup values are cached during package execution.  It is critical to know how cache modes affect the result of the lookup and the performance of the package, as choosing the wrong setting can lead to poorly performing packages, and in some cases, incorrect results. Full Cache The full cache mode setting is the default cache mode selection in the SSIS lookup transformation.  Like the name implies, full cache mode will cause the lookup transformation to retrieve and store in SSIS cache the entire set of data from the specified lookup location.  As a result, the data flow in which the lookup transformation resides will not start processing any data buffers until all of the rows from the lookup query have been cached in SSIS. The most commonly used cache mode is the full cache setting, and for good reason.  The full cache setting has the most practical applications, and should be considered the go-to cache setting when dealing with an untested set of data. With a moderately sized set of reference data, a lookup transformation using full cache mode usually performs well.  Full cache mode does not require multiple round trips to the database, since the entire reference result set is cached prior to data flow execution. There are a few potential gotchas to be aware of when using full cache mode.  First, you can see some performance issues – memory pressure in particular – when using full cache mode against large sets of reference data.  If the table you use for the lookup is very large (either deep or wide, or perhaps both), there’s going to be a performance cost associated with retrieving and caching all of that data.  Also, keep in mind that when doing a lookup on character data, full cache mode will always do a case-sensitive (and in some cases, space-sensitive) string comparison even if your database is set to a case-insensitive collation.  This is because the in-memory lookup uses a .NET string comparison (which is case- and space-sensitive) as opposed to a database string comparison (which may be case sensitive, depending on collation).  There’s a relatively easy workaround in which you can use the UPPER() or LOWER() function in the pipeline data and the reference data to ensure that case differences do not impact the success of your lookup operation.  Again, neither of these present a reason to avoid full cache mode, but should be used to determine whether full cache mode should be used in a given situation. Full cache mode is ideally useful when one or all of the following conditions exist: The size of the reference data set is small to moderately sized The size of the pipeline data set (the data you are comparing to the lookup table) is large, is unknown at design time, or is unpredictable Each distinct key value(s) in the pipeline data set is expected to be found multiple times in that set of data Partial Cache When using the partial cache setting, lookup values will still be cached, but only as each distinct value is encountered in the data flow.  Initially, each distinct value will be retrieved individually from the specified source, and then cached.  To be clear, this is a row-by-row lookup for each distinct key value(s). This is a less frequently used cache setting because it addresses a narrower set of scenarios.  Because each distinct key value(s) combination requires a relational round trip to the lookup source, performance can be an issue, especially with a large pipeline data set to be compared to the lookup data set.  If you have, for example, a million records from your pipeline data source, you have the potential for doing a million lookup queries against your lookup data source (depending on the number of distinct values in the key column(s)).  Therefore, one has to be keenly aware of the expected row count and value distribution of the pipeline data to safely use partial cache mode. Using partial cache mode is ideally suited for the conditions below: The size of the data in the pipeline (more specifically, the number of distinct key column) is relatively small The size of the lookup data is too large to effectively store in cache The lookup source is well indexed to allow for fast retrieval of row-by-row values No Cache As you might guess, selecting no cache mode will not add any values to the lookup cache in SSIS.  As a result, every single row in the pipeline data set will require a query against the lookup source.  Since no data is cached, it is possible to save a small amount of overhead in SSIS memory in cases where key values are not reused.  In the real world, I don’t see a lot of use of the no cache setting, but I can imagine some edge cases where it might be useful. As such, it’s critical to know your data before choosing this option.  Obviously, performance will be an issue with anything other than small sets of data, as the no cache setting requires row-by-row processing of all of the data in the pipeline. I would recommend considering the no cache mode only when all of the below conditions are true: The reference data set is too large to reasonably be loaded into SSIS memory The pipeline data set is small and is not expected to grow There are expected to be very few or no duplicates of the key values(s) in the pipeline data set (i.e., there would be no benefit from caching these values) Conclusion The cache mode, an often-overlooked setting on the SSIS lookup component, represents an important design decision in your SSIS data flow.  Choosing the right lookup cache mode directly impacts the fidelity of your results and the performance of package execution.  Know how this selection impacts your ETL loads, and you’ll end up with more reliable, faster packages. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: SSIS

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• Oracle Database 12 c New Partition Maintenance Features by Gwen Lazenby

  - by hamsun

  One of my favourite new features in Oracle Database 12c is the ability to perform partition maintenance operations on multiple partitions. This means we can now add, drop, truncate and merge multiple partitions in one operation, and can split a single partition into more than two partitions also in just one command. This would certainly have made my life slightly easier had it been available when I administered a data warehouse at Oracle 9i. To demonstrate this new functionality and syntax, I am going to create two tables, ORDERS and ORDERS_ITEMS which have a parent-child relationship. ORDERS is to be partitioned using range partitioning on the ORDER_DATE column, and ORDER_ITEMS is going to partitioned using reference partitioning and its foreign key relationship with the ORDERS table. This form of partitioning was a new feature in 11g and means that any partition maintenance operations performed on the ORDERS table will also take place on the ORDER_ITEMS table as well. First create the ORDERS table - SQL CREATE TABLE orders ( order_id NUMBER(12), order_date TIMESTAMP, order_mode VARCHAR2(8), customer_id NUMBER(6), order_status NUMBER(2), order_total NUMBER(8,2), sales_rep_id NUMBER(6), promotion_id NUMBER(6), CONSTRAINT orders_pk PRIMARY KEY(order_id) ) PARTITION BY RANGE(order_date) (PARTITION Q1_2007 VALUES LESS THAN (TO_DATE('01-APR-2007','DD-MON-YYYY')), PARTITION Q2_2007 VALUES LESS THAN (TO_DATE('01-JUL-2007','DD-MON-YYYY')), PARTITION Q3_2007 VALUES LESS THAN (TO_DATE('01-OCT-2007','DD-MON-YYYY')), PARTITION Q4_2007 VALUES LESS THAN (TO_DATE('01-JAN-2008','DD-MON-YYYY')) ); Table created. Now the ORDER_ITEMS table SQL CREATE TABLE order_items ( order_id NUMBER(12) NOT NULL, line_item_id NUMBER(3) NOT NULL, product_id NUMBER(6) NOT NULL, unit_price NUMBER(8,2), quantity NUMBER(8), CONSTRAINT order_items_fk FOREIGN KEY(order_id) REFERENCES orders(order_id) on delete cascade) PARTITION BY REFERENCE(order_items_fk) tablespace example; Table created. Now look at DBA_TAB_PARTITIONS to get details of what partitions we have in the two tables – SQL select table_name,partition_name, partition_position position, high_value from dba_tab_partitions where table_owner='SH' and table_name like 'ORDER_%' order by partition_position, table_name; TABLE_NAME PARTITION_NAME POSITION HIGH_VALUE -------------- --------------- -------- ------------------------- ORDERS Q1_2007 1 TIMESTAMP' 2007-04-01 00:00:00' ORDER_ITEMS Q1_2007 1 ORDERS Q2_2007 2 TIMESTAMP' 2007-07-01 00:00:00' ORDER_ITEMS Q2_2007 2 ORDERS Q3_2007 3 TIMESTAMP' 2007-10-01 00:00:00' ORDER_ITEMS Q3_2007 3 ORDERS Q4_2007 4 TIMESTAMP' 2008-01-01 00:00:00' ORDER_ITEMS Q4_2007 4 Just as an aside it is also now possible in 12c to use interval partitioning on reference partitioned tables. In 11g it was not possible to combine these two new partitioning features. For our first example of the new 12cfunctionality, let us add all the partitions necessary for 2008 to the tables using one command. Notice that the partition specification part of the add command is identical in format to the partition specification part of the create command as shown above - SQL alter table orders add PARTITION Q1_2008 VALUES LESS THAN (TO_DATE('01-APR-2008','DD-MON-YYYY')), PARTITION Q2_2008 VALUES LESS THAN (TO_DATE('01-JUL-2008','DD-MON-YYYY')), PARTITION Q3_2008 VALUES LESS THAN (TO_DATE('01-OCT-2008','DD-MON-YYYY')), PARTITION Q4_2008 VALUES LESS THAN (TO_DATE('01-JAN-2009','DD-MON-YYYY')); Table altered. Now look at DBA_TAB_PARTITIONS and we can see that the 4 new partitions have been added to both tables – SQL select table_name,partition_name, partition_position position, high_value from dba_tab_partitions where table_owner='SH' and table_name like 'ORDER_%' order by partition_position, table_name; TABLE_NAME PARTITION_NAME POSITION HIGH_VALUE -------------- --------------- -------- ------------------------- ORDERS Q1_2007 1 TIMESTAMP' 2007-04-01 00:00:00' ORDER_ITEMS Q1_2007 1 ORDERS Q2_2007 2 TIMESTAMP' 2007-07-01 00:00:00' ORDER_ITEMS Q2_2007 2 ORDERS Q3_2007 3 TIMESTAMP' 2007-10-01 00:00:00' ORDER_ITEMS Q3_2007 3 ORDERS Q4_2007 4 TIMESTAMP' 2008-01-01 00:00:00' ORDER_ITEMS Q4_2007 4 ORDERS Q1_2008 5 TIMESTAMP' 2008-04-01 00:00:00' ORDER_ITEMS Q1_2008 5 ORDERS Q2_2008 6 TIMESTAMP' 2008-07-01 00:00:00' ORDER_ITEM Q2_2008 6 ORDERS Q3_2008 7 TIMESTAMP' 2008-10-01 00:00:00' ORDER_ITEMS Q3_2008 7 ORDERS Q4_2008 8 TIMESTAMP' 2009-01-01 00:00:00' ORDER_ITEMS Q4_2008 8 Next, we can drop or truncate multiple partitions by giving a comma separated list in the alter table command. Note the use of the plural ‘partitions’ in the command as opposed to the singular ‘partition’ prior to 12c– SQL alter table orders drop partitions Q3_2008,Q2_2008,Q1_2008; Table altered. Now look at DBA_TAB_PARTITIONS and we can see that the 3 partitions have been dropped in both the two tables – TABLE_NAME PARTITION_NAME POSITION HIGH_VALUE -------------- --------------- -------- ------------------------- ORDERS Q1_2007 1 TIMESTAMP' 2007-04-01 00:00:00' ORDER_ITEMS Q1_2007 1 ORDERS Q2_2007 2 TIMESTAMP' 2007-07-01 00:00:00' ORDER_ITEMS Q2_2007 2 ORDERS Q3_2007 3 TIMESTAMP' 2007-10-01 00:00:00' ORDER_ITEMS Q3_2007 3 ORDERS Q4_2007 4 TIMESTAMP' 2008-01-01 00:00:00' ORDER_ITEMS Q4_2007 4 ORDERS Q4_2008 5 TIMESTAMP' 2009-01-01 00:00:00' ORDER_ITEMS Q4_2008 5 Now let us merge all the 2007 partitions together to form one single partition – SQL alter table orders merge partitions Q1_2005, Q2_2005, Q3_2005, Q4_2005 into partition Y_2007; Table altered. TABLE_NAME PARTITION_NAME POSITION HIGH_VALUE -------------- --------------- -------- ------------------------- ORDERS Y_2007 1 TIMESTAMP' 2008-01-01 00:00:00' ORDER_ITEMS Y_2007 1 ORDERS Q4_2008 2 TIMESTAMP' 2009-01-01 00:00:00' ORDER_ITEMS Q4_2008 2 Splitting partitions is a slightly more involved. In the case of range partitioning one of the new partitions must have no high value defined, and in list partitioning one of the new partitions must have no list of values defined. I call these partitions the ‘everything else’ partitions, and will contain any rows contained in the original partition that are not contained in the any of the other new partitions. For example, let us split the Y_2007 partition back into 4 quarterly partitions – SQL alter table orders split partition Y_2007 into (PARTITION Q1_2007 VALUES LESS THAN (TO_DATE('01-APR-2007','DD-MON-YYYY')), PARTITION Q2_2007 VALUES LESS THAN (TO_DATE('01-JUL-2007','DD-MON-YYYY')), PARTITION Q3_2007 VALUES LESS THAN (TO_DATE('01-OCT-2007','DD-MON-YYYY')), PARTITION Q4_2007); Now look at DBA_TAB_PARTITIONS to get details of the new partitions – TABLE_NAME PARTITION_NAME POSITION HIGH_VALUE -------------- --------------- -------- ------------------------- ORDERS Q1_2007 1 TIMESTAMP' 2007-04-01 00:00:00' ORDER_ITEMS Q1_2007 1 ORDERS Q2_2007 2 TIMESTAMP' 2007-07-01 00:00:00' ORDER_ITEMS Q2_2007 2 ORDERS Q3_2007 3 TIMESTAMP' 2007-10-01 00:00:00' ORDER_ITEMS Q3_2007 3 ORDERS Q4_2007 4 TIMESTAMP' 2008-01-01 00:00:00' ORDER_ITEMS Q4_2007 4 ORDERS Q4_2008 5 TIMESTAMP' 2009-01-01 00:00:00' ORDER_ITEMS Q4_2008 5 Partition Q4_2007 has a high value equal to the high value of the original Y_2007 partition, and so has inherited its upper boundary from the partition that was split. As for a list partitioning example let look at the following another table, SALES_PAR_LIST, which has 2 partitions, Americas and Europe and a partitioning key of country_name. SQL select table_name,partition_name, high_value from dba_tab_partitions where table_owner='SH' and table_name = 'SALES_PAR_LIST'; TABLE_NAME PARTITION_NAME HIGH_VALUE -------------- --------------- ----------------------------- SALES_PAR_LIST AMERICAS 'Argentina', 'Canada', 'Peru', 'USA', 'Honduras', 'Brazil', 'Nicaragua' SALES_PAR_LIST EUROPE 'France', 'Spain', 'Ireland', 'Germany', 'Belgium', 'Portugal', 'Denmark' Now split the Americas partition into 3 partitions – SQL alter table sales_par_list split partition americas into (partition south_america values ('Argentina','Peru','Brazil'), partition north_america values('Canada','USA'), partition central_america); Table altered. Note that no list of values was given for the ‘Central America’ partition. However it should have inherited any values in the original ‘Americas’ partition that were not assigned to either the ‘North America’ or ‘South America’ partitions. We can confirm this by looking at the DBA_TAB_PARTITIONS view. SQL select table_name,partition_name, high_value from dba_tab_partitions where table_owner='SH' and table_name = 'SALES_PAR_LIST'; TABLE_NAME PARTITION_NAME HIGH_VALUE --------------- --------------- -------------------------------- SALES_PAR_LIST SOUTH_AMERICA 'Argentina', 'Peru', 'Brazil' SALES_PAR_LIST NORTH_AMERICA 'Canada', 'USA' SALES_PAR_LIST CENTRAL_AMERICA 'Honduras', 'Nicaragua' SALES_PAR_LIST EUROPE 'France', 'Spain', 'Ireland', 'Germany', 'Belgium', 'Portugal', 'Denmark' In conclusion, I hope that DBA’s whose work involves maintaining partitions will find the operations a bit more straight forward to carry out once they have upgraded to Oracle Database 12c. Gwen Lazenby is a Principal Training Consultant at Oracle. She is part of Oracle University's Core Technology delivery team based in the UK, teaching Database Administration and Linux courses. Her specialist topics include using Oracle Partitioning and Parallelism in Data Warehouse environments, as well as Oracle Spatial and RMAN.

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• Waterfall Model (SDLC) vs. Prototyping Model

  The characters in the fable of the Tortoise and the Hare can easily be used to demonstrate the similarities and differences between the Waterfall and Prototyping software development models. This children fable is about a race between a consistently slow moving but steadfast turtle and an extremely fast but unreliable rabbit. After closely comparing each character’s attributes in correlation with both software development models, a trend seems to appear in that the Waterfall closely resembles the Tortoise in that Waterfall Model is typically a slow moving process that is broken up in to multiple sequential steps that must be executed in a standard linear pattern. The Tortoise can be quoted several times in the story saying “Slow and steady wins the race.” This is the perfect mantra for the Waterfall Model in that this model is seen as a cumbersome and slow moving. Waterfall Model Phases Requirement Analysis & Definition This phase focuses on defining requirements for a project that is to be developed and determining if the project is even feasible. Requirements are collected by analyzing existing systems and functionality in correlation with the needs of the business and the desires of the end users. The desired output for this phase is a list of specific requirements from the business that are to be designed and implemented in the subsequent steps. In addition this phase is used to determine if any value will be gained by completing the project. System Design This phase focuses primarily on the actual architectural design of a system, and how it will interact within itself and with other existing applications. Projects at this level should be viewed at a high level so that actual implementation details are decided in the implementation phase. However major environmental decision like hardware and platform decision are typically decided in this phase. Furthermore the basic goal of this phase is to design an application at the system level in those classes, interfaces, and interactions are defined. Additionally decisions about scalability, distribution and reliability should also be considered for all decisions. The desired output for this phase is a functional  design document that states all of the architectural decisions that have been made in regards to the project as well as a diagrams like a sequence and class diagrams. Software Design This phase focuses primarily on the refining of the decisions found in the functional design document. Classes and interfaces are further broken down in to logical modules based on the interfaces and interactions previously indicated. The output of this phase is a formal design document. Implementation / Coding This phase focuses primarily on implementing the previously defined modules in to units of code. These units are developed independently are intergraded as the system is put together as part of a whole system. Software Integration & Verification This phase primarily focuses on testing each of the units of code developed as well as testing the system as a whole. There are basic types of testing at this phase and they include: Unit Test and Integration Test. Unit Test are built to test the functionality of a code unit to ensure that it preforms its desired task. Integration testing test the system as a whole because it focuses on results of combining specific units of code and validating it against expected results. The output of this phase is a test plan that includes test with expected results and actual results. System Verification This phase primarily focuses on testing the system as a whole in regards to the list of project requirements and desired operating environment. Operation & Maintenance his phase primarily focuses on handing off the competed project over to the customer so that they can verify that all of their requirements have been met based on their original requirements. This phase will also validate the correctness of their requirements and if any changed need to be made. In addition, any problems not resolved in the previous phase will be handled in this section. The Waterfall Model’s linear and sequential methodology does offer a project certain advantages and disadvantages. Advantages of the Waterfall Model Simplistic to implement and execute for projects and/or company wide Limited demand on resources Large emphasis on documentation Disadvantages of the Waterfall Model Completed phases cannot be revisited regardless if issues arise within a project Accurate requirement are never gather prior to the completion of the requirement phase due to the lack of clarification in regards to client’s desires. Small changes or errors that arise in applications may cause additional problems The client cannot change any requirements once the requirements phase has been completed leaving them no options for changes as they see their requirements changes as the customers desires change. Excess documentation Phases are cumbersome and slow moving Learn more about the Major Process in the Sofware Development Life Cycle and Waterfall Model. Conversely, the Hare shares similar traits with the prototyping software development model in that ideas are rapidly converted to basic working examples and subsequent changes are made to quickly align the project with customers desires as they are formulated and as software strays from the customers vision. The basic concept of prototyping is to eliminate the use of well-defined project requirements. Projects are allowed to grow as the customer needs and request grow. Projects are initially designed according to basic requirements and are refined as requirement become more refined. This process allows customer to feel their way around the application to ensure that they are developing exactly what they want in the application This model also works well for determining the feasibility of certain approaches in regards to an application. Prototypes allow for quickly developing examples of implementing specific functionality based on certain techniques. Advantages of Prototyping Active participation from users and customers Allows customers to change their mind in specifying requirements Customers get a better understanding of the system as it is developed Earlier bug/error detection Promotes communication with customers Prototype could be used as final production Reduced time needed to develop applications compared to the Waterfall method Disadvantages of Prototyping Promotes constantly redefining project requirements that cause major system rewrites Potential for increased complexity of a system as scope of the system expands Customer could believe the prototype as the working version. Implementation compromises could increase the complexity when applying updates and or application fixes When companies trying to decide between the Waterfall model and Prototype model they need to evaluate the benefits and disadvantages for both models. Typically smaller companies or projects that have major time constraints typically head for more of a Prototype model approach because it can reduce the time needed to complete the project because there is more of a focus on building a project and less on defining requirements and scope prior to the start of a project. On the other hand, Companies with well-defined requirements and time allowed to generate proper documentation should steer towards more of a waterfall model because they are in a position to obtain clarified requirements and have to design and optimal solution prior to the start of coding on a project.

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• SQL Server Table Polling by Multiple Subscribers

  - by Daniel Hester

  Background Designing Stored Procedures that are safe for multiple subscribers (to call simultaneously) can be challenging.  For example let’s say that you want multiple worker processes to poll a shared work queue that’s encapsulated as a SQL Table. This is a common scenario and through experience you’ll find that you want to use Table Hints to prevent unwanted locking when performing simultaneous queries on the same table. There are three table hints to consider: NOLOCK, READPAST and UPDLOCK. Both NOLOCK and READPAST table hints allow you to SELECT from a table without placing a LOCK on that table. However, SELECTs with the READPAST hint will ignore any records that are locked due to being updated/inserted (or otherwise “dirty”), whereas a SELECT with NOLOCK ignores all locks including dirty reads. For the initial update of the flag (that marks the record as available for subscription) I don’t use the NOLOCK Table Hint because I want to be sensitive to the “active” records in the table and I want to exclude them.  I use an Update Lock (UPDLOCK) in conjunction with a WHERE clause that uses a sub-select with a READPAST Table Hint in order to explicitly lock the records I’m updating (UPDLOCK) but not place a lock on the table when selecting the records that I’m going to update (READPAST). UPDATES should be allowed to lock the rows affected because we’re probably changing a flag on a record so that it is not included in a SELECT from another subscriber. On the UPDATE statement we should explicitly use the UPDLOCK to guard against lock escalation. A SELECT to check for the next record(s) to process can result in a shared read lock being held by more than one subscriber polling the shared work queue (SQL table). It is expected that more than one worker process (or server) might try to process the same new record(s) at the same time. When each process then tries to obtain the update lock, none of them can because another process has a shared read lock in place. Thus without the UPDLOCK hint the result would be a lock escalation deadlock; however with the UPDLOCK hint this condition is mitigated against. Note that using the READPAST table hint requires that you also set the ISOLATION LEVEL of the transaction to be READ COMMITTED (rather than the default of SERIALIZABLE). Guidance In the Stored Procedure that returns records to the multiple subscribers: Perform the UPDATE first. Change the flag that makes the record available to subscribers.  Additionally, you may want to update a LastUpdated datetime field in order to be able to check for records that “got stuck” in an intermediate state or for other auditing purposes. In the UPDATE statement use the (UPDLOCK) Table Hint on the UPDATE statement to prevent lock escalation. In the UPDATE statement also use a WHERE Clause that uses a sub-select with a (READPAST) Table Hint to select the records that you’re going to update. In the UPDATE statement use the OUTPUT clause in conjunction with a Temporary Table to isolate the record(s) that you’ve just updated and intend to return to the subscriber. This is the fastest way to update the record(s) and to get the records’ identifiers within the same operation. Finally do a set-based SELECT on the main Table (using the Temporary Table to identify the records in the set) with either a READPAST or NOLOCK table hint.  Use NOLOCK if there are other processes (besides the multiple subscribers) that might be changing the data that you want to return to the multiple subscribers; or use READPAST if you're sure there are no other processes (besides the multiple subscribers) that might be updating column data in the table for other purposes (e.g. changes to a person’s last name).  NOLOCK is generally the better fit in this part of the scenario. See the following as an example: CREATE PROCEDURE [dbo].[usp_NewCustomersSelect] AS BEGIN -- OVERRIDE THE DEFAULT ISOLATION LEVEL SET TRANSACTION ISOLATION LEVEL READ COMMITTED -- SET NOCOUNT ON SET NOCOUNT ON -- DECLARE TEMP TABLE -- Note that this example uses CustomerId as an identifier; -- you could just use the Identity column Id if that’s all you need. DECLARE @CustomersTempTable TABLE ( CustomerId NVARCHAR(255) ) -- PERFORM UPDATE FIRST -- [Customers] is the name of the table -- [Id] is the Identity Column on the table -- [CustomerId] is the business document key used to identify the -- record globally, i.e. in other systems or across SQL tables -- [Status] is INT or BIT field (if the status is a binary state) -- [LastUpdated] is a datetime field used to record the time of the -- last update UPDATE [Customers] WITH (UPDLOCK) SET [Status] = 1, [LastUpdated] = GETDATE() OUTPUT [INSERTED].[CustomerId] INTO @CustomersTempTable WHERE ([Id] = (SELECT TOP 100 [Id] FROM [Customers] WITH (READPAST) WHERE ([Status] = 0) ORDER BY [Id] ASC)) -- PERFORM SELECT FROM ENTITY TABLE SELECT [C].[CustomerId], [C].[FirstName], [C].[LastName], [C].[Address1], [C].[Address2], [C].[City], [C].[State], [C].[Zip], [C].[ShippingMethod], [C].[Id] FROM [Customers] AS [C] WITH (NOLOCK), @CustomersTempTable AS [TEMP] WHERE ([C].[CustomerId] = [TEMP].[CustomerId]) END In a system that has been designed to have multiple status values for records that need to be processed in the Work Queue it is necessary to have a “Watch Dog” process by which “stale” records in intermediate states (such as “In Progress”) are detected, i.e. a [Status] of 0 = New or Unprocessed; a [Status] of 1 = In Progress; a [Status] of 2 = Processed; etc.. Thus, if you have a business rule that states that the application should only process new records if all of the old records have been processed successfully (or marked as an error), then it will be necessary to build a monitoring process to detect stalled or stale records in the Work Queue, hence the use of the LastUpdated column in the example above. The Status field along with the LastUpdated field can be used as the criteria to detect stalled / stale records. It is possible to put this watchdog logic into the stored procedure above, but I would recommend making it a separate monitoring function. In writing the stored procedure that checks for stale records I would recommend using the same kind of lock semantics as suggested above. The example below looks for records that have been in the “In Progress” state ([Status] = 1) for greater than 60 seconds: CREATE PROCEDURE [dbo].[usp_NewCustomersWatchDog] AS BEGIN -- TO OVERRIDE THE DEFAULT ISOLATION LEVEL SET TRANSACTION ISOLATION LEVEL READ COMMITTED -- SET NOCOUNT ON SET NOCOUNT ON DECLARE @MaxWait int; SET @MaxWait = 60 IF EXISTS (SELECT 1 FROM [dbo].[Customers] WITH (READPAST) WHERE ([Status] = 1) AND (DATEDIFF(s, [LastUpdated], GETDATE()) > @MaxWait)) BEGIN SELECT 1 AS [IsWatchDogError] END ELSE BEGIN SELECT 0 AS [IsWatchDogError] END END Downloads The zip file below contains two SQL scripts: one to create a sample database with the above stored procedures and one to populate the sample database with 10,000 sample records.  I am very grateful to Red-Gate software for their excellent SQL Data Generator tool which enabled me to create these sample records in no time at all. References http://msdn.microsoft.com/en-us/library/ms187373.aspx http://www.techrepublic.com/article/using-nolock-and-readpast-table-hints-in-sql-server/6185492 http://geekswithblogs.net/gwiele/archive/2004/11/25/15974.aspx http://grounding.co.za/blogs/romiko/archive/2009/03/09/biztalk-sql-receive-location-deadlocks-dirty-reads-and-isolation-levels.aspx

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• Building dynamic OLAP data marts on-the-fly

  - by DrJohn

  At the forthcoming SQLBits conference, I will be presenting a session on how to dynamically build an OLAP data mart on-the-fly. This blog entry is intended to clarify exactly what I mean by an OLAP data mart, why you may need to build them on-the-fly and finally outline the steps needed to build them dynamically. In subsequent blog entries, I will present exactly how to implement some of the techniques involved. What is an OLAP data mart? In data warehousing parlance, a data mart is a subset of the overall corporate data provided to business users to meet specific business needs. Of course, the term does not specify the technology involved, so I coined the term "OLAP data mart" to identify a subset of data which is delivered in the form of an OLAP cube which may be accompanied by the relational database upon which it was built. To clarify, the relational database is specifically create and loaded with the subset of data and then the OLAP cube is built and processed to make the data available to the end-users via standard OLAP client tools. Why build OLAP data marts? Market research companies sell data to their clients to make money. To gain competitive advantage, market research providers like to "add value" to their data by providing systems that enhance analytics, thereby allowing clients to make best use of the data. As such, OLAP cubes have become a standard way of delivering added value to clients. They can be built on-the-fly to hold specific data sets and meet particular needs and then hosted on a secure intranet site for remote access, or shipped to clients' own infrastructure for hosting. Even better, they support a wide range of different tools for analytical purposes, including the ever popular Microsoft Excel. Extension Attributes: The Challenge One of the key challenges in building multiple OLAP data marts based on the same 'template' is handling extension attributes. These are attributes that meet the client's specific reporting needs, but do not form part of the standard template. Now clearly, these extension attributes have to come into the system via additional files and ultimately be added to relational tables so they can end up in the OLAP cube. However, processing these files and filling dynamically altered tables with SSIS is a challenge as SSIS packages tend to break as soon as the database schema changes. There are two approaches to this: (1) dynamically build an SSIS package in memory to match the new database schema using C#, or (2) have the extension attributes provided as name/value pairs so the file's schema does not change and can easily be loaded using SSIS. The problem with the first approach is the complexity of writing an awful lot of complex C# code. The problem of the second approach is that name/value pairs are useless to an OLAP cube; so they have to be pivoted back into a proper relational table somewhere in the data load process WITHOUT breaking SSIS. How this can be done will be part of future blog entry. What is involved in building an OLAP data mart? There are a great many steps involved in building OLAP data marts on-the-fly. The key point is that all the steps must be automated to allow for the production of multiple OLAP data marts per day (i.e. many thousands, each with its own specific data set and attributes). Now most of these steps have a great deal in common with standard data warehouse practices. The key difference is that the databases are all built to order. The only permanent database is the metadata database (shown in orange) which holds all the metadata needed to build everything else (i.e. client orders, configuration information, connection strings, client specific requirements and attributes etc.). The staging database (shown in red) has a short life: it is built, populated and then ripped down as soon as the OLAP Data Mart has been populated. In the diagram below, the OLAP data mart comprises the two blue components: the Data Mart which is a relational database and the OLAP Cube which is an OLAP database implemented using Microsoft Analysis Services (SSAS). The client may receive just the OLAP cube or both components together depending on their reporting requirements.  So, in broad terms the steps required to fulfil a client order are as follows: Step 1: Prepare metadata Create a set of database names unique to the client's order Modify all package connection strings to be used by SSIS to point to new databases and file locations. Step 2: Create relational databases Create the staging and data mart relational databases using dynamic SQL and set the database recovery mode to SIMPLE as we do not need the overhead of logging anything Execute SQL scripts to build all database objects (tables, views, functions and stored procedures) in the two databases Step 3: Load staging database Use SSIS to load all data files into the staging database in a parallel operation Load extension files containing name/value pairs. These will provide client-specific attributes in the OLAP cube. Step 4: Load data mart relational database Load the data from staging into the data mart relational database, again in parallel where possible Allocate surrogate keys and use SSIS to perform surrogate key lookup during the load of fact tables Step 5: Load extension tables & attributes Pivot the extension attributes from their native name/value pairs into proper relational tables Add the extension attributes to the views used by OLAP cube Step 6: Deploy & Process OLAP cube Deploy the OLAP database directly to the server using a C# script task in SSIS Modify the connection string used by the OLAP cube to point to the data mart relational database Modify the cube structure to add the extension attributes to both the data source view and the relevant dimensions Remove any standard attributes that not required Process the OLAP cube Step 7: Backup and drop databases Drop staging database as it is no longer required Backup data mart relational and OLAP database and ship these to the client's infrastructure Drop data mart relational and OLAP database from the build server Mark order complete Start processing the next order, ad infinitum. So my future blog posts and my forthcoming session at the SQLBits conference will all focus on some of the more interesting aspects of building OLAP data marts on-the-fly such as handling the load of extension attributes and how to dynamically alter the structure of an OLAP cube using C#.

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• Pet Peeves with the Windows Phone 7 Marketplace

  - by Bil Simser

  Have you ever noticed how something things just gnaw at your very being. This is the case with the WP7 marketplace, the Zune software, and the things that drive me batshit crazy with a side of fries. To go. I wanted to share. XBox Live is Not the Centre of the Universe Okay, it’s fine that the Zune software has an XBox live tag for games so can see them clearly but do we really need to have it shoved down our throats. On every click? Click on Games in the marketplace: The first thing that it defaults to on the filters on the right is XBox Live: Okay. Fine. However if you change it (say to Paid) then click onto a title when you come back from that title is the filter still set to Paid? No. It’s back to XBox Live again. Really? Give us a break. If you change to any filter on any other genre then click on the selected title, it doesn’t revert back to anything. It stays on the selection you picked. Let’s be fair here. The Games genre should behave just like every other one. If I pick Paid then when I come back to the list please remember that. Double Dipping On the subject of XBox Live titles, Microsoft (and developers who have an agreement with Microsoft to produce Live titles, which generally rules out indie game developers) is double dipping with regards to exposure of their titles. Here’s the Puzzle and Trivia Game section on the Marketplace for XBox Live titles: And here’s the same category filtered on Paid titles: See the problem? Two indie titles while the rest are XBox Live ones. So while XBL has it’s filter, they also get to showcase their wares in the Paid and Free filters as well. If you’re going to have an XBox Live filter then use it and stop pushing down indie titles until they’re off the screen (on some genres this is already the case). Free and Paid titles should be just that and not include XBox Live ones. If you’re really stoked that people can’t find the Free XBox Live titles vs. the paid ones, then create a Free XBox Live filter and a Paid XBox Live filter. I don’t think we would mind much. Whose Trial is it Anyways? You might notice apps in the marketplace with titles like “My Fart App Professional Lite” or “Silicon Lamb Spleen Builder Free”. When you submit and app to the marketplace it can either be free or paid. If it’s a paid app you also have the option to submit it with Trial capabilities. It’s up to you to decide what you offer in the trial version but trial versions can be purchased from within the app so after someone trys out your app (for free) and wants to unlock the Super Secret Obama Spy Ring Level, they can just go to the marketplace from your app (if you built that functionality in) and upgrade to the paid version. However it creates a rift of sorts when it comes to visibility. Some developers go the route of the paid app with a trial version, others decide to submit *two* apps instead of one. One app is the “Free” or “Lite” verions and the other is the paid version. Why go to the hassle of submitting two apps when you can just create a trial version in the same app? Again, visibility. There’s no way to tell Paid apps with Trial versions and ones without (it’s an option, you don’t have to provide trial versions, although I think it’s a good idea). However there is a way to see the Free apps from the Paid ones so some submit the two apps and have the Free version have links to buy the paid one (again through the Marketplace tasks in the API). What we as developers need for visibility is a new filter. Trial. That’s it. It would simply filter on Paid apps that have trial capabilities and surface up those apps just like the free ones. If Microsoft added this filter to the marketplace, it would eliminate the need for people to submit their “Free” and “Lite” versions and make it easier for the developer not to have to maintain two systems. I mean, is it really that hard? Can’t be any more difficult than the XBox Live Filter that’s already there. Location is Everything The last thing on my bucket list is about location. When I launch Zune I’m running in my native location setting, Canada. What’s great is that I navigate to the Travel Tools section where I have one of my apps and behold the splendour that I see: There are my apps in the number 1 and number 4 slot for top selling in that category. I show it to my wife to make up for the sleepless nights writing this stuff and we dance around and celebrate. Then I change my location on my operation system to United States and re-launch Zune. WTF? My flight app has slipped to the 10th spot (I’m only showing 4 across here out of the 7 in Zune) and my border check app that was #1 is now in the 32nd spot! End of celebration. Not only is relevance being looked at here, I value the comments people make on may apps as do most developers. I want to respond to them and show them that I’m listening. The next version of my border app will provide multiple camera angles. However when I’m running in my native Canada location, I only see two reviews. Changing over to United States I see fourteen! While there are tools out there to provide with you a unified view, I shouldn’t have to rely on them. My own Zune desktop software should allow me to see everything. I realize that some developers will submit an app and only target it for some locations and that’s their choice. However I shouldn’t have to jump through hoops to see what apps are ahead of mine, or see people comments and ratings. Another proposal. Either unify the marketplace (i.e. when I’m looking at it show me everything combined) or let me choose a filter. I think the first option might be difficult as you’re trying to average out top selling apps across all markets and have to deal with some apps that have been omitted from some markets. Although I think you could come up with a set of use cases that would handle that, maybe that’s too much work. At the very least, let us developers view the markets in a drop down or something from within the Zune desktop. Having to shut down Zune, change our location, and re-launch Zune to see other perspectives is just too onerous. A Call to Action These are just one mans opinion. Do you agree? Disagree? Feel hungry for a bacon sandwich? Let everyone know via the comments below. Perhaps someone from Microsoft will be reading and take some of these ideas under advisement. Maybe not, but at least let’s get the word out that we really want to see some change. Egypt can do it, why not WP7 developers!

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• Can't remove burg theme packages

  - by Lassi

  Today after trying to install and remove BURG and few themes I faced an issue. Now I can't install or remove anything. Here is the output (unfortunately partly in Finnish, I couldn't change language since it also seems to depend on package listings: lassi@lassi-ubuntu:~$ sudo apt-get autoremove Luetaan pakettiluetteloita... Valmis Muodostetaan riippuvuussuhteiden puu Luetaan tilatietoja... Valmis Seuraavat paketit POISTETAAN: burg-theme-fortune burg-theme-gnome burg-theme-picchio 0 päivitetty, 0 uutta asennusta, 3 poistettavaa ja 0 päivittämätöntä. 3 ei asennettu kokonaan tai poistettiin. Toiminnon jälkeen vapautuu 7 180 k t levytilaa. Haluatko jatkaa [K/e]? k (Luetaan tietokantaa... 166462 files and directories currently installed.) Poistetaan pakettia burg-theme-fortune... sudo: update-burg: command not found dpkg: virhe käsiteltäessä burg-theme-fortune (--remove): aliprosessi installed post-removal script palautti virhetilakoodin 1 Poistetaan pakettia burg-theme-gnome... sudo: update-burg: command not found dpkg: virhe käsiteltäessä burg-theme-gnome (--remove): aliprosessi installed post-removal script palautti virhetilakoodin 1 Poistetaan pakettia burg-theme-picchio... sudo: update-burg: command not found dpkg: virhe käsiteltäessä burg-theme-picchio (--remove): aliprosessi installed post-removal script palautti virhetilakoodin 1 Käsittelyssä tapahtui liian monta virhettä: burg-theme-fortune burg-theme-gnome burg-theme-picchio E: Sub-process /usr/bin/dpkg returned an error code (1) Basically what seems to happen is this: It creates the package lists, then tries to remove packet burg-theme-fortune. This fails as update-burg command was not found. Then dpkg reports an error while processing the packet. Same goes with all 3 packages. In the end it claims that there were too many errors, and packages stay installed. I also tried installing burg as it tries to run command update-burg, but appears that it tries to delete these packages always when I try to install or remove or do anything with apt. Any ideas how I could solve this issue? Edit: Here is the output of apt-get install burg (tried installing again to get English output) lassi@lassi-ubuntu:~$ LC_ALL=C sudo apt-get install burg [sudo] password for lassi: Reading package lists... Done Building dependency tree Reading state information... Done burg is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 3 not fully installed or removed. Need to get 0 B/6169 kB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 167497 files and directories currently installed.) Preparing to replace burg-theme-fortune 0.5.0-1 (using .../burg-theme-fortune_0.5.0-1_all.deb) ... Unpacking replacement burg-theme-fortune ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: warning: subprocess old post-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error processing /var/cache/apt/archives/burg-theme-fortune_0.5.0-1_all.deb (--unpack): subprocess new post-removal script returned error exit status 1 Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error while cleaning up: subprocess new post-removal script returned error exit status 1 Preparing to replace burg-theme-gnome 0.5.0-1 (using .../burg-theme-gnome_0.5.0-1_all.deb) ... Unpacking replacement burg-theme-gnome ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: warning: subprocess old post-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error processing /var/cache/apt/archives/burg-theme-gnome_0.5.0-1_all.deb (--unpack): subprocess new post-removal script returned error exit status 1 Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error while cleaning up: subprocess new post-removal script returned error exit status 1 Preparing to replace burg-theme-picchio 0.5.0-1 (using .../burg-theme-picchio_0.5.0-1_all.deb) ... Unpacking replacement burg-theme-picchio ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: warning: subprocess old post-removal script returned error exit status 1 dpkg - trying script from the new package instead ... Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error processing /var/cache/apt/archives/burg-theme-picchio_0.5.0-1_all.deb (--unpack): subprocess new post-removal script returned error exit status 1 Generating burg.cfg ... /usr/sbin/burg-probe: error: cannot stat `/boot/burg/locale'. No path or device is specified. Try `/usr/sbin/burg-probe --help' for more information. dpkg: error while cleaning up: subprocess new post-removal script returned error exit status 1 Errors were encountered while processing: /var/cache/apt/archives/burg-theme-fortune_0.5.0-1_all.deb /var/cache/apt/archives/burg-theme-gnome_0.5.0-1_all.deb /var/cache/apt/archives/burg-theme-picchio_0.5.0-1_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1) lassi@lassi-ubuntu:~$

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• Answers to Your Common Oracle Database Lifecycle Management Questions

  - by Scott McNeil

  We recently ran a live webcast on Strategies for Managing Oracle Database's Lifecycle. There were tons of questions from our audience that we simply could not get to during the hour long presentation. Below are some of those questions along with their answers. Enjoy! Question: In the webcast the presenter talked about “gold” configuration standards, for those who want to use this technique, could you recommend a best practice to consider or follow? How do I get started? Answer:Gold configuration standardization is a quick and easy way to improve availability through consistency. Start by choosing a reference database and saving the configuration to the Oracle Enterprise Manager repository using the Save Configuration feature. Next create a comparison template using the Oracle provided template as a starting point and modify the ignored properties to eliminate expected differences in your environment. Finally create a comparison specification using the comparison template you created plus your saved gold configuration and schedule it to run on a regular basis. Don’t forget to fill in the email addresses of those you want to notify upon drift detection. Watch the database configuration management demo to learn more. Question: Can Oracle Lifecycle Management Pack for Database help with patching an Oracle Real Application Cluster (RAC) environment? Answer: Yes, Oracle Enterprise Manager supports both parallel and rolling patch application of Oracle Real Application Clusters. The use of rolling patching is recommended as there is no downtime involved. For more details watch this demo. Question: What are some of the things administrators can do to control configuration drift? Why is it important? Answer:Configuration drift is one of the main causes of instability and downtime of applications. Oracle Enterprise Manager makes it easy to manage and control drift using scheduled configuration comparisons combined with comparison templates. Question: Does Oracle Enterprise Manager 12c Release 2 offer an incremental update feature for "gold" images? For instance, if the source binary has a higher PSU level, what is the best approach to update the existing "gold" image in the software library? Do you have to create a new image or can you just update the original one? Answer:Provisioning Profiles (Gold images) can contain the installation files and database configuration templates. Although it is possible to make some changes to the profile after creation (mainly to configuration), it is normally recommended to simply create a new profile after applying a patch to your reference database. Question: The webcast talked about enforcing in-house standards, does Oracle Enterprise Manager 12c offer verification of your databases and systems to those standards? For example, the initial "gold" image has been massively deployed over time, and there may be some changes to it. How can you do regular checks from Enterprise Manager to ensure the in-house standards are being enforced? Answer:There are really two methods to validate conformity to standards. The first method is to use gold standards which you compare other databases to report unwanted differences. This method uses a new comparison template technology which allows users to ignore known differences (i.e. SID, Start time, etc) which results in a report only showing important or non-conformant differences. This method is quick to setup and configure and recommended for those who want to get started validating compliance quickly. The second method leverages the new compliance framework which allows the creation of specific and robust validations. These compliance rules are grouped into standards which can be assigned to databases quickly and easily. Compliance rules allow for targeted and more sophisticated validation beyond the basic equals operation available in the comparison method. The compliance framework can be used to implement just about any internal or industry standard. The compliance results will track current and historic compliance scores at the overall and individual database targets. When the issue is resolved, the score is automatically affected. Compliance framework is the recommended long term solution for validating compliance using Oracle Enterprise Manager 12c. Check out this demo on database compliance to learn more. Question: If you are using the integration between Oracle Enterprise Manager and My Oracle Support in an "offline" mode, how do you know if you have the latest My Oracle Support metadata? Answer:In Oracle Enterprise Manager 12c Release 2, you now only need to download one zip file containing all of the metadata xmls files. There is no indication that the metadata has changed but you could run a checksum on the file and compare it to the previously downloaded version to see if it has changed. Question: What happens if a patch fails while administrators are applying it to a database or system? Answer:A large portion of Oracle Enterprise Manager's patch automation is the pre-requisite checks that happen to ensure the highest level of confidence the patch will successfully apply. It is recommended you test the patch in a non-production environment and save the patch plan as a template once successful so you can create new plans using the saved template. If you are using the recommended ‘out of place’ patching methodology, there is no urgency because the database is still running as the cloned Oracle home is being patched. Users can address the issue and restart the patch procedure at the point it left off. If you are using 'in place' method, you can address the issue and continue where the procedure left off. Question: Can Oracle Enterprise Manager 12c R2 compare configurations between more than one target at the same time? Answer:Oracle Enterprise Manager 12c can compare any number of target configurations at one time. This is the basis of many important use cases including Configuration Drift Management. These comparisons can also be scheduled on a regular basis and emails notification sent should any differences appear. To learn more about configuration search and compare watch this demo. Question: How is data comparison done since changes are taking place in a live production system? Answer:There are many things to keep in mind when using the data comparison feature (as part of the Change Management ability to compare table data). It was primarily intended to be used for maintaining consistency of important but relatively static data. For example, application seed data and application setup configuration. This data does not change often but is critical when testing an application to ensure results are consistent with production. It is not recommended to use data comparison on highly dynamic data like transactional tables or very large tables. Question: Which versions of Oracle Database can be monitored through Oracle Enterprise Manager 12c? Answer:Oracle Database versions: 9.2.0.8, 10.1.0.5, 10.2.0.4, 10.2.0.5, 11.1.0.7, 11.2.0.1, 11.2.0.2, 11.2.0.3. Watch the On-Demand Webcast Stay Connected: Twitter | Facebook | YouTube | Linkedin | NewsletterDownload the Oracle Enterprise Manager Cloud Control12c Mobile app

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• Securing an ADF Application using OES11g: Part 1

  - by user12587121

  Future releases of the Oracle stack should allow ADF applications to be secured natively with Oracle Entitlements Server (OES). In a sequence of postings here I explore one way to achive this with the current technology, namely OES 11.1.1.5 and ADF 11.1.1.6. ADF Security Basics ADF Bascis The Application Development Framework (ADF) is Oracle’s preferred technology for developing GUI based Java applications.  It can be used to develop a UI for Swing applications or, more typically in the Oracle stack, for Web and J2EE applications.  ADF is based on and extends the Java Server Faces (JSF) technology.  To get an idea, Oracle provides an online demo to showcase ADF components. ADF can be used to develop just the UI part of an application, where, for example, the data access layer is implemented using some custom Java beans or EJBs.  However ADF also has it’s own data access layer, ADF Business Components (ADF BC) that will allow rapid integration of data from data bases and Webservice interfaces to the ADF UI component.   In this way ADF helps implement the MVC  approach to building applications with UI and data components. The canonical tutorial for ADF is to open JDeveloper, define a connection to a database, drag and drop a table from the database view to a UI page, build and deploy.  One has an application up and running very quickly with the ability to quickly integrate changes to, for example, the DB schema. ADF allows web pages to be created graphically and components like tables, forms, text fields, graphs and so on to be easily added to a page.  On top of JSF Oracle have added drag and drop tooling with JDeveloper and declarative binding of the UI to the data layer, be it database, WebService or Java beans.  An important addition is the bounded task flow which is a reusable set of pages and transitions.   ADF adds some steps to the page lifecycle defined in JSF and adds extra widgets including powerful visualizations. It is worth pointing out that the Oracle Web Center product (portal, content management and so on) is based on and extends ADF. ADF Security ADF comes with it’s own security mechanism that is exposed by JDeveloper at development time and in the WLS Console and Enterprise Manager (EM) at run time. The security elements that need to be addressed in an ADF application are: authentication, authorization of access to web pages, task-flows, components within the pages and data being returned from the model layer. One  typically relies on WLS to handle authentication and because of this users and groups will also be handled by WLS.  Typically in a Dev environment, users and groups are stored in the WLS embedded LDAP server. One has a choice when enabling ADF security (Application->Secure->Configure ADF Security) about whether to turn on ADF authorization checking or not: In the case where authorization is enabled for ADF one defines a set of roles in which we place users and then we grant access to these roles to the different ADF elements (pages or task flows or elements in a page). An important notion here is the difference between Enterprise Roles and Application Roles. The idea behind an enterprise role is that is defined in terms of users and LDAP groups from the WLS identity store.  “Enterprise” in the sense that these are things available for use to all applications that use that store.  The other kind of role is an Application Role and the idea is that  a given application will make use of Enterprise roles and users to build up a set of roles for it’s own use.  These application roles will be available only to that application.   The general idea here is that the enterprise roles are relatively static (for example an Employees group in the LDAP directory) while application roles are more dynamic, possibly depending on time, location, accessed resource and so on.  One of the things that OES adds that is that we can define these dynamic membership conditions in Role Mapping Policies. To make this concrete, here is how, at design time in Jdeveloper, one assigns these rights in Jdeveloper, which puts them into a file called jazn-data.xml: When the ADF app is deployed to a WLS this JAZN security data is pushed to the system-jazn-data.xml file of the WLS deployment for the policies and application roles and to the WLS backing LDAP for the users and enterprise roles.  Note the difference here: after deploying the application we will see the users and enterprise roles show up in the WLS LDAP server.  But the policies and application roles are defined in the system-jazn-data.xml file.  Consult the embedded WLS LDAP server to manage users and enterprise roles by going to the domain console and then Security Realms->myrealm->Users and Groups: For production environments (or in future to share this data with OES) one would then perform the operation of “reassociating” this security policy and application role data to a DB schema (or an LDAP).  This is done in the EM console by reassociating the Security Provider.  This blog posting has more explanations and references on this reassociation process. If ADF Authentication and Authorization are enabled then the Security Policies for a deployed application can be managed in EM.  Our goal is to be able to manage security policies for the applicaiton rather via OES and it's console. Security Requirements for an ADF Application With this package tour of ADF security we can see that to secure an ADF application with we would expect to be able to take care of at least the following items: Authentication, including a user and user-group store Authorization for page access Authorization for bounded Task Flow access.  A bounded task flow has only one point of entry and so if we protect that entry point by calling to OES then all the pages in the flow are protected.  Authorization for viewing data coming from the data access layer In the next posting we will describe a sample ADF application and required security policies. References ADF Dev Guide: Fusion Middleware Fusion Developer's Guide for Oracle Application Development Framework: Enabling ADF Security in a Fusion Web Application Oracle tutorial on securing a sample ADF application, appears to require ADF 11.1.2 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• 10 tape technology features that make you go hmm.

  - by Karoly Vegh

  A week ago an Oracle/StorageTek Tape Specialist, Christian Vanden Balck, visited Vienna, and agreed to visit customers to do techtalks and update them about the technology boom going around tape. I had the privilege to attend some of his sessions and noted the information and features that took the customers by surprise and made them think. Allow me to share the top 10: I. StorageTek as a brand: StorageTek is one of he strongest names in the Tape field. The brand itself was valued so much by customers that even after Sun Microsystems acquiring StorageTek and the Oracle acquiring Sun the brand lives on with all the Oracle tapelibraries are officially branded StorageTek.See http://www.oracle.com/us/products/servers-storage/storage/tape-storage/overview/index.html II. Disk information density limitations: Disk technology struggles with information density. You haven't seen the disk sizes exploding lately, have you? That's partly because there are physical limits on a disk platter. The size is given, the number of platters is limited, they just can't grow, and are running out of physical area to write to. Now, in a T10000C tape cartridge we have over 1000m long tape. There you go, you have got your physical space and don't need to stuff all that data crammed together. You can write in a reliable pattern, and have space to grow too. III. Oracle has a market share of 62% worldwide in recording head manufacturing. That's right. If you are running LTO drives, with a good chance you rely on StorageTek production. That's two out of three LTO recording heads produced worldwide.  IV. You can store 1 Exabyte data in a single tape library. Yes, an Exabyte. That is 1000 Petabytes. Or, a million Terabytes. A thousand million GigaBytes. You can store that in a stacked StorageTek SL8500 tapelibrary. In one SL8500 you can put 10.000 T10000C cartridges, that store 10TB data (compressed). You can stack 10 of these SL8500s together. Boom. 1000.000 TB.(n.b.: stacking means interconnecting the libraries. Yes, cartridges are moved between the stacked libraries automatically.)  V. EMC: 'Tape doesn't suck after all. We moved on.': Do you remember the infamous 'Tape sucks, move on' Datadomain slogan? Of course they had to put it that way, having only had disk products. But here's a fun fact: on the EMCWorld 2012 there was a major presence of a Tape-tech company - EMC, in a sudden burst of sanity is embracing tape again. VI. The miraculous T10000C: Oracle StorageTek has developed an enterprise-grade tapedrive and cartridge, the T10000C. With awesome numbers: The Cartridge: Native 5TB capacity, 10TB with compression Over a kilometer long tape within the cartridge. And it's locked when unmounted, no rattling of your data.  Replaced the metalparticles datalayer with BaFe (bariumferrite) - metalparticles lose around 7% of magnetism within 30 days. BaFe does not. Yes we employ solid-state physicists doing R&D on demagnetisation in our labs. Can be partitioned, storage tiering within the cartridge!  The Drive: 2GB Cache Encryption implemented in HW - no performance hit 252 MB/s native sustained data rate, beats disk technology by far. Not to mention peak throughput.  Leading the tape while never touching the data side of it, protecting your data physically too Data integritiy checking (CRC recalculation) on tape within the drive without having to read it back to the server reordering data from tape-order, delivering it back in application-order  writing 32 tracks at once, reading them back for CRC check at once VII. You only use 20% of your data on a regular basis. The rest 80% is just lying around for years. On continuously spinning disks. Doubly consuming energy (power+cooling), blocking diskstorage capacity. There is a solution called SAM (Storage Archive Manager) that provides you a filesystem unifying disk and tape, moving data on-demand and for clients transparently between the different storage tiers. You can share these filesystems with NFS or CIFS for clients, and enjoy the low TCO of tape. Tapes don't spin. They sit quietly in their slots, storing 10TB data, using no energy, producing no heat, automounted when a client accesses their data.See: http://www.oracle.com/us/products/servers-storage/storage/storage-software/storage-archive-manager/overview/index.html VIII. HW supported for three decades: Did you know that the original PowderHorn library was released in '87 and has been only discontinued in 2010? That is over two decades of supported operation. Tape libraries are - just like the data carrying on tapecartridges - built for longevity. Oh, and the T10000C cartridge has 30-year archival life for long-term retention.  IX. Tape is easy to manage: Have you heard of Tape Storage Analytics? It is a central graphical tool to summarize, monitor, analyze dataflow, health and performance of drives and libraries, see: http://www.oracle.com/us/products/servers-storage/storage/tape-storage/tape-analytics/overview/index.html X. The next generation: The T10000B drives were able to reuse the T10000A cartridges and write on them even more data. On the same cartridges. We call this investment protection, and this is very important for Oracle for the future too. We usually support two generations of cartridges together. The current drive is a T10000C. (...I know I promised to enlist 10, but I got still two more I really want to mention. Allow me to work around the problem: ) X++. The TallBots, the robots moving around the cartridges in the StorageTek library from tapeslots to the drives are cableless. Cables, belts, chains running to moving parts in a library cause maintenance downtimes. So StorageTek eliminated them. The TallBots get power, commands, even firmwareupgrades through the rails they are running on. Also, the TallBots don't just hook'n'pull the tapes out of their slots, they actually grip'n'lift them out. No friction, no scratches, no zillion little plastic particles floating around in the library, in the drives, on your data. (X++)++: Tape beats SSDs and Disks. In terms of throughput (252 MB/s), in terms of TCO: disks cause around 290x more power and cooling, in terms of capacity: 10TB on a single media and soon more.  So... do you need to store large amounts of data? Are you legally bound to archive it for dozens of years? Would you benefit from automatic storage tiering? Have you got large mediachunks to be streamed at times? Have you got power and cooling issues in the growing datacenters? Do you find EMC's 180° turn of tape attitude interesting, but appreciate it at the same time? With all that, you aren't alone. The most data on this planet is stored on tape. Tape is coming. Big time.

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• NUMA-aware placement of communication variables

  - by Dave

  For classic NUMA-aware programming I'm typically most concerned about simple cold, capacity and compulsory misses and whether we can satisfy the miss by locally connected memory or whether we have to pull the line from its home node over the coherent interconnect -- we'd like to minimize channel contention and conserve interconnect bandwidth. That is, for this style of programming we're quite aware of where memory is homed relative to the threads that will be accessing it. Ideally, a page is collocated on the node with the thread that's expected to most frequently access the page, as simple misses on the page can be satisfied without resorting to transferring the line over the interconnect. The default "first touch" NUMA page placement policy tends to work reasonable well in this regard. When a virtual page is first accessed, the operating system will attempt to provision and map that virtual page to a physical page allocated from the node where the accessing thread is running. It's worth noting that the node-level memory interleaving granularity is usually a multiple of the page size, so we can say that a given page P resides on some node N. That is, the memory underlying a page resides on just one node. But when thinking about accesses to heavily-written communication variables we normally consider what caches the lines underlying such variables might be resident in, and in what states. We want to minimize coherence misses and cache probe activity and interconnect traffic in general. I don't usually give much thought to the location of the home NUMA node underlying such highly shared variables. On a SPARC T5440, for instance, which consists of 4 T2+ processors connected by a central coherence hub, the home node and placement of heavily accessed communication variables has very little impact on performance. The variables are frequently accessed so likely in M-state in some cache, and the location of the home node is of little consequence because a requester can use cache-to-cache transfers to get the line. Or at least that's what I thought. Recently, though, I was exploring a simple shared memory point-to-point communication model where a client writes a request into a request mailbox and then busy-waits on a response variable. It's a simple example of delegation based on message passing. The server polls the request mailbox, and having fetched a new request value, performs some operation and then writes a reply value into the response variable. As noted above, on a T5440 performance is insensitive to the placement of the communication variables -- the request and response mailbox words. But on a Sun/Oracle X4800 I noticed that was not the case and that NUMA placement of the communication variables was actually quite important. For background an X4800 system consists of 8 Intel X7560 Xeons . Each package (socket) has 8 cores with 2 contexts per core, so the system is 8x8x2. Each package is also a NUMA node and has locally attached memory. Every package has 3 point-to-point QPI links for cache coherence, and the system is configured with a twisted ladder "mobius" topology. The cache coherence fabric is glueless -- there's not central arbiter or coherence hub. The maximum distance between any two nodes is just 2 hops over the QPI links. For any given node, 3 other nodes are 1 hop distant and the remaining 4 nodes are 2 hops distant. Using a single request (client) thread and a single response (server) thread, a benchmark harness explored all permutations of NUMA placement for the two threads and the two communication variables, measuring the average round-trip-time and throughput rate between the client and server. In this benchmark the server simply acts as a simple transponder, writing the request value plus 1 back into the reply field, so there's no particular computation phase and we're only measuring communication overheads. In addition to varying the placement of communication variables over pairs of nodes, we also explored variations where both variables were placed on one page (and thus on one node) -- either on the same cache line or different cache lines -- while varying the node where the variables reside along with the placement of the threads. The key observation was that if the client and server threads were on different nodes, then the best placement of variables was to have the request variable (written by the client and read by the server) reside on the same node as the client thread, and to place the response variable (written by the server and read by the client) on the same node as the server. That is, if you have a variable that's to be written by one thread and read by another, it should be homed with the writer thread. For our simple client-server model that means using split request and response communication variables with unidirectional message flow on a given page. This can yield up to twice the throughput of less favorable placement strategies. Our X4800 uses the QPI 1.0 protocol with source-based snooping. Briefly, when node A needs to probe a cache line it fires off snoop requests to all the nodes in the system. Those recipients then forward their response not to the original requester, but to the home node H of the cache line. H waits for and collects the responses, adjudicates and resolves conflicts and ensures memory-model ordering, and then sends a definitive reply back to the original requester A. If some node B needed to transfer the line to A, it will do so by cache-to-cache transfer and let H know about the disposition of the cache line. A needs to wait for the authoritative response from H. So if a thread on node A wants to write a value to be read by a thread on node B, the latency is dependent on the distances between A, B, and H. We observe the best performance when the written-to variable is co-homed with the writer A. That is, we want H and A to be the same node, as the writer doesn't need the home to respond over the QPI link, as the writer and the home reside on the very same node. With architecturally informed placement of communication variables we eliminate at least one QPI hop from the critical path. Newer Intel processors use the QPI 1.1 coherence protocol with home-based snooping. As noted above, under source-snooping a requester broadcasts snoop requests to all nodes. Those nodes send their response to the home node of the location, which provides memory ordering, reconciles conflicts, etc., and then posts a definitive reply to the requester. In home-based snooping the snoop probe goes directly to the home node and are not broadcast. The home node can consult snoop filters -- if present -- and send out requests to retrieve the line if necessary. The 3rd party owner of the line, if any, can respond either to the home or the original requester (or even to both) according to the protocol policies. There are myriad variations that have been implemented, and unfortunately vendor terminology doesn't always agree between vendors or with the academic taxonomy papers. The key is that home-snooping enables the use of a snoop filter to reduce interconnect traffic. And while home-snooping might have a longer critical path (latency) than source-based snooping, it also may require fewer messages and less overall bandwidth. It'll be interesting to reprise these experiments on a platform with home-based snooping. While collecting data I also noticed that there are placement concerns even in the seemingly trivial case when both threads and both variables reside on a single node. Internally, the cores on each X7560 package are connected by an internal ring. (Actually there are multiple contra-rotating rings). And the last-level on-chip cache (LLC) is partitioned in banks or slices, which with each slice being associated with a core on the ring topology. A hardware hash function associates each physical address with a specific home bank. Thus we face distance and topology concerns even for intra-package communications, although the latencies are not nearly the magnitude we see inter-package. I've not seen such communication distance artifacts on the T2+, where the cache banks are connected to the cores via a high-speed crossbar instead of a ring -- communication latencies seem more regular.

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• Visiting the Fire Station in Coromandel

  Hm, I just tried to remember how we actually came up with this cool idea... but it's already too blurred and it doesn't really matter after all. Anyway, if I remember correctly (IIRC), it happened during one of the Linux meetups at Mugg & Bean, Bagatelle where Ajay and I brought our children along and we had a brief conversation about how cool it would be to check out one of the fire stations here in Mauritius. We both thought that it would be a great experience and adventure for the little ones. An idea takes shape And there we go, down the usual routine these... having an idea, checking out the options and discussing who's doing what. Except this time, it was all up to Ajay, and he did a fantastic job. End of August, he told me that he got in touch with one of his friends which actually works as a fire fighter at the station in Coromandel and that there could be an option to come and visit them (soon). A couple of days later - Confirmed! Be there, and in time... What time? Anyway, doesn't really matter... Everything was settled and arranged. I asked the kids on Friday afternoon if they might be interested to see the fire engines and what a fire fighter is doing. Of course, they were all in! Getting up early on Sunday morning isn't really a regular exercise for all of us but everything went smooth and after a short breakfast it was time to leave. Where are we going? Are we there yet? Now, we are in Bambous. Why do you go this way? The kids were so much into it. Absolutely amazing to see their excitement. Are we there yet? Well, we went through the sugar cane fields towards Chebel and then down into the industrial zone at Coromandel. Honestly, I had a clue where the fire station is located but having Google Maps in reach that shouldn't be a problem in case that we might get lost. But my worries were washed away when our children guided us... "There! Over there are the fire engines! We have to turn left, dad." - No comment, the kids were right! As we were there a little bit too early, we parked the car and the kids started to explore the area and outskirts of the fire station. Some minutes later, as if we had placed an order a unit of two cars had to go out for an alarm and the kids could witness them leaving as closely as possible. Sirens on and wow!!! Ladder truck L32 - MAN truck with Rosenbauer built-up and equipment by Metz Taking the tour Ajay arrived shortly after that and guided us finally inside the station to meet with his pal. The three guys were absolutely well-prepared and showed us around in the hall, explaining that there two units out at the moment. But the ladder truck (with max. 32m expandable height) was still around we all got a great insight into the technique and equipment on the vehicle. It was amazing to see all three kids listening to Mambo as give some figures about the truck and how the fire fighters are actually it. The children and 'our' fire fighters of the day had great fun with the various fire engines Absolutely fantastic that the children were allowed to experience this - we had so much fun! Ajay's son brought two of his toy fire engines along, shared them with ours, and they all played very well together. As a parent it was really amazing to see them at such an ease. Enough theory Shortly afterwards the ladder truck was moved outside, got stabilised and ready to go for 'real-life' exercising. With the additional equipment of safety helmets, security belts and so on, we all got a first-hand impression about how it could be as a fire-fighter. Actually, I was totally amazed by the curiousity and excitement of my BWE. She was really into it and asked lots of interesting questions - in general but also technical. And while our fighters were busy with Ajay and family, I gave her some more details and explanations about the truck, the expandable ladder, the safety cage at the top and other equipment available. Safety first! No exceptions and always be prepared for the worst case... Also, the equipped has been checked prior to excuse - This is your life saver... Hooked up and ready to go... ...of course not too high. This is just a demonstration - and 32 meters above ground isn't for everyone. Well, after that it was me that had the asking looks on me, and I finally revealed to the local fire fighters that I was in the auxiliary fire brigade, more precisely in the hazard department, for more than 10 years. So not a professional fire fighter but at least a passionate and educated one as them. Inside the station Our fire fighters really took their time to explain their daily job to kids, provided them access to operation seat on the ladder truck and how the truck cabin is actually equipped with the different radios and so on. It was really a great time. Later on we had a brief tour through the building itself, and again all of our questions were answered. We had great fun and started to joke about bits and pieces. For me it was also very interesting to see the comparison between the fire station here in Mauritius and the ones I have been to back in Germany. Amazing to see them completely captivated in the play - the children had lots of fun! Also, that there are currently ten fire stations all over the island, plus two additional but private ones at the airport and at the harbour. The newest one is actually down in Black River on the west coast because the time from Quatre Bornes takes too long to have any chance of an effective alarm at all. IMHO, a very good decision as time is the most important factor in getting fire incidents under control. After all it was great experience for all of us, especially for the children to see and understand that their toy trucks are only copies of the real thing and that the job of a (professional) fire fighter is very important in our society. Don't forget that those guys run into the danger zone while you're trying to get away from it as much as possible. Another unit just came back from a grass fire - and shortly after they went out again. No time to rest, too much to do! Mauritian Fire Fighters now and (maybe) in the future... Thank you! It was an honour to be around! Thank you to Ajay for organising and arranging this Sunday morning event, and of course of Big Thank You to the three guys that took some time off to have us at the Fire Station in Coromandel and guide us through their daily job! And remember to call 115 in case of emergencies!

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• How To: Using spatial data with Entity Framework and Connector/Net

  - by GABMARTINEZ

  One of the new features introduced in Entity Framework 5.0 is the incorporation of some new types of data within an Entity Data Model: the spatial data types. These types allow us to perform operations on coordinates values in an easier way. There's no need to add stored routines or functions for every operation among these geometry types, now the user can have the alternative to put this logic on his application or keep it in the database. In the new 6.7.4 version there's also this new feature incorporated to Connector/Net library so our users can start exploring it and could provide us some feedback or comments about this new functionality. Through this tutorial on how to create a Code First Entity Model with a geometry column, we'll show an example on using Geometry types and some common operations when using geometry types inside an application. Requirements: - Connector/Net 6.7.4 - Entity Framework 5.0 version - .NET Framework 4.5 version - Basic understanding on Entity Framework and C# language. - An installed and running instance of MySQL Server 5.5.x or 5.6.10 version- Visual Studio 2012. Step One: Create a new Console Application  Inside Visual Studio select File->New Project menu option and select the Console Application template. Also make sure the .Net 4.5 version is selected so the new features for EF 5.0 will work with the application. Step Two: Add the Entity Framework Package For adding the Entity Framework Package there is more than one option: the package manager console or the Manage Nuget Packages option dialog. If you want to open the Package Manager Console, go to the Tools Menu -> Library Package Manager -> Package Manager Console. On the Package Manager Console Type:Install-Package EntityFrameworkThis will add the reference to the project of the latest released No alpha version of Entity Framework. Step Three: Adding Entity class and DBContext We'll add a simple class that represents a table entity to save some places and its location using a DBGeometry column that will be mapped to a Geometry type in MySQL. After that some operations can be performed using this data. public class MyPlace { [Key] public int Id { get; set; } public string name { get; set; } public DbGeometry location { get; set; } } public class JourneyDb : DbContext { public DbSet<MyPlace> MyPlaces { get; set; } }  Also make sure to add the connection string to the App.Config file as in the example: <?xml version="1.0" encoding="utf-8"?> <configuration>   <configSections>     <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->     <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />   </configSections>   <startup>     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />   </startup>   <connectionStrings>     <add name="JourneyDb" connectionString="server=localhost;userid=root;pwd=;database=journeydb" providerName="MySql.Data.MySqlClient"/>   </connectionStrings>   <entityFramework>     </entityFramework> </configuration> Note also that the <entityFramework> section is empty.Step Four: Adding some new records.On the Program.cs file add the following code for the Main method so the Database gets created and also some new data can be added to the new table. This code adds some records containing some determinate locations. After being added a distance function will be used to know how much distance has each location in reference to the Queens Village Station in New York. static void Main(string[] args)    {     using (JourneyDb cxt = new JourneyDb())      {        cxt.Database.Delete();        cxt.Database.Create();         cxt.MyPlaces.Add(new MyPlace()        {          name = "JFK INTERNATIONAL AIRPORT OF NEW YORK",          location = DbGeometry.FromText("POINT(40.644047 -73.782291)"),        });         cxt.MyPlaces.Add(new MyPlace()        {          name = "ALLEY POND PARK",          location = DbGeometry.FromText("POINT(40.745696 -73.742638)"),        });       cxt.MyPlaces.Add(new MyPlace()        {          name = "CUNNINGHAM PARK",          location = DbGeometry.FromText("POINT(40.735031 -73.768387)"),        });         cxt.MyPlaces.Add(new MyPlace()        {          name = "QUEENS VILLAGE STATION",          location = DbGeometry.FromText("POINT(40.717957 -73.736501)"),        });         cxt.SaveChanges();         var points = (from p in cxt.MyPlaces                      select new { p.name, p.location });        foreach (var item in points)       {         Console.WriteLine("Location " + item.name + " has a distance in Km from Queens Village Station " + DbGeometry.FromText("POINT(40.717957 -73.736501)").Distance(item.location) * 100);       }       Console.ReadKey();      }  }}Output : Location JFK INTERNATIONAL AIRPORT OF NEW YORK has a distance from Queens Village Station 8.69448802402959 Km. Location ALLEY POND PARK has a distance from Queens Village Station 2.84097675104912 Km. Location CUNNINGHAM PARK has a distance from Queens Village Station 3.61695793727275 Km. Location QUEENS VILLAGE STATION has a distance from Queens Village Station 0 Km. Conclusion:Adding spatial data to a table is easier than before when having Entity Framework 5.0. This new Entity Framework feature that handles spatial data columns within the Data layer has a lot of integrated functions and methods toease this type of tasks.Notes:This version of Connector/Net is just released as GA so is preatty much stable to be used on a ProductionEnvironment. Please send us your comments or questions using this blog or at the Forums where we keep answering any questions you have about Connector/Net and MySQL Server.A copy of this sample project can be downloaded here. This application does not include any library so you will haveto add them before running it. Happly MySQL/.Net Coding.

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• Getting Started With Tailoring Business Processes

  - by Richard Bingham

  In this article, and for the sake of simplicity, we will use the term “On-Premise” to mean a deployment where you have design-time development access to the instance, including administration of the technology components, the applications filesystem, and the database. In reality this might be a local development instance that is then supported by a team who can deploy your customizations to the restricted production instance equivalents. Tools Overview Firstly let’s look at the Design-Time tools within JDeveloper for customizing and extending the artifacts of a Business Process. In essence this falls into two buckets; SOA Composite Editor for working with BPEL processes, and the BPM Studio. The SOA Composite Editor As a standard extension to JDeveloper, this graphical design tool should be familiar to anyone previously worked with Oracle SOA Server. With easy-to-use modeling capability, backed-up by full XML source-view (for read-only), it provides everything that is needed to implement the technical design. In simple terms, once deployed to the remote SOA Server the composite components (like Mediator) leverage the Event Delivery Network (EDN) for interaction with the application logic. If you are customizing an existing Fusion Applications BPEL process then be aware that it does support MDS-based customization layers just like Page Composer where different customizations are used based on the run-time context, like for a specific Product or Business Unit. This also makes them safe from patching and upgrades, although only a single active version of the composite is available at run-time. This is defined by a field on the composite record, available in Enterprise Manager. Obviously if you wish to fire different activities and tasks based on the user context then you can should include switches to fork the flows in your custom BPEL process. Figure 1 – A BPEL process in Composite Editor The following describes the simplified steps for making customizations to BPEL processes. This is the most common method of changing the business processes of Fusion Applications, as over 400 BPEL-based composite applications are provided out-of-the-box. Setup your local Fusion Applications JDeveloper environment. The SOA Composite Editor should be installed as part of the Fusion Applications extension. If there are problems you can also find it under the ‘Check for Updates’ help menu option. Since SOA Server is not part of the JDeveloper integrated WebLogic Server, setup a standalone WebLogic environment for deploying and testing. Obviously you might use a Fusion Applications development instance also. Package the existing standard Fusion Applications SOA Composite using Enterprise Manager and export it as a complete SOA Archive (SAR) file, resulting in a local .jar file. You may need to ask your system administrator for this. Import the exported SAR .jar file into JDeveloper using the File menu, under the option ‘SOA Archive into SOA Project’. In JDeveloper set the appropriate customization layer values, and then change from the default role to the Fusion Applications Customization Developer role. Make the customizations and save the application project. Finally redeploy the composite application, either to a direct Application Server connection, or as a fresh SAR (jar) file that can then be re-imported and deployed via Enterprise Manager. The Business Process Management (BPM) Suite In addition to the relatively low-level development environment associated with BPEL process creation, Oracle provides a suite of products that allow business process adjustments to be made without the need for some of the programming skills.  The aim is to abstract much of the technical implementation and to provide a Business Analyst tools for immediately implementing organization changes. Obviously there are some limitations on what they can do, however the BPM Suite functionality increases with each release and for the majority of the cases the tools remains as applicable as its developer-orientated sister. At the current time business processes must be explicitly coded to support just one of these use-cases, either BPEL for developer use or BPM for business analyst use. That said, they both run on the same SOA Server in much the same way. The components bundled in each SOA Composite Application can be verified by inspection through Enterprise Manager. Figure 2 – A BPM Process in JDeveloper BPM Suite. BPM processes are written in a standard notation (BPMN) and the modeling tools are very similar to that of BPEL. The steps to deploy a custom BPM process are also essentially much the same, since the BPM process is bundled into a SOA Composite just like a BPEL process. As such the SOA Composite Editor  actually has support for both artifacts and even allows use of them together, such as a calling a BPM process as a partnerlink from a BPEL process. For more details see the references below. Business Analyst Tooling In addition to using JDeveloper extensions for BPM development, there are run-time tools that Business Analysts can use to make adjustments, so that without high costs of an IT project the system can be tuned to match changes to the business operation. The first tool to consider is the BPM Composer, deployed with the middleware SOA Server and accessible online, and for Fusion Applications it is under the Business Process icon on the homepage of the Application Composer. Figure 3 – Business Process Composer showing a CRM process flow. The key difference between this and using JDeveloper is that the BPM Composer has a Business Catalog prepopulated with features and functions that can be used, mostly through registered WebServices. This means no coding or complex interface development is required, simply drag-drop-configure. The items in the business catalog are seeded by either Oracle (as a BPM Template) or added to by your own custom development. You cannot create or generate catalog content from BPM Composer directly. As per the screenshot you can see the Business Catalog content in the BPM Project browser region. In addition, other online tools for use by Business Analysts include the BPM Worklist application for editing business rules and approval management configuration, plus the SOA Composer which focuses on non-approval business rules and domain value maps. At the current time there are only a handful of BPM processes shipped with Fusion Applications HCM and CRM, including on-boarding workers and processing customer registrations.  This also means a limited number of associated BPM Templates provided out-of-the-box, therefore a limited Business Catalog. That said, BPM-based extension is a powerful capability to leverage and will most likely develop going forwards, especially for use in SaaS deployments where full design-time JDeveloper access is not available. Further Reading For BPEL – Fusion Applications Extensibility Guide – Section 12 For BPM – Fusion Applications Extensibility Guide – Section 7 The product-specific documentation and implementation guides for Fusion Applications Fusion Middleware Developers Guide for SOA Suite Modeling and Implementation Guide for Oracle Business Process Management User’s Guide for Oracle Business Process Composer Oracle University courses on BPM Suite and SOA Development

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• BRE (Business Rules Engine) Data Services is out...!!!

  - by Vishal

  A few months ago we at Tellago had open sourced the BizTalk Data Services. We were meanwhile working on other artifacts which comes along with BizTalk Server like the “Business Rules Engine”.  We are happy to announce the first version of BRE Data Services. BRE Data Services is a same concept which we covered through BTS Data Services, providing a RESTFul OData – based API to interact with the Business Rules Engine via HTTP using ATOM Publishing Protocol or JSON as the encoding mechanism.   In the first version release, we mainly focused on the browsing, querying and searching BRE artifacts via a RESTFul interface. Also along with that we provide the functionality to execute Business Rules by inserting the Facts for policies via the IUpdatable implementation of WCF Data Services.   The BRE Data Services API provides a lightweight interface for managing Business Rules Engine artifacts such as Policies, Rules, Vocabularies, Conditions, Actions, Facts etc. The following are some examples which details some of the available features in the current version of the API.   Basic Querying: Querying BRE Policies http://localhost/BREDataServices/BREMananagementService.svc/Policies Querying BRE Rules http://localhost/BREDataServices/BREMananagementService.svc/Rules Querying BRE Vocabularies http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies   Navigation: The BRE Data Services API also leverages WCF Data Services to enable navigation across related different BRE objects. Querying a specific Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies(‘PolicyName’) Querying a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules(‘RuleName’) Querying all Rules under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Rules Querying all Facts under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Facts Querying all Actions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying all Conditions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying a specific Vocabulary: http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies('VocabName')   Implementation: With the BRE Data Services, we also provide the functionality of executing a particular policy via HTTP. There are couple of ways you can do that though the API.   Ø First is though Service Operations feature of WCF Data Services in which you can execute the Facts by passing them in the URL itself. This is a very simple implementations of the executing the policies due to the limitations & restrictions (only primitive types of input parameters which can be passed) currently of the Service Operations of the WCF Data Services. Below is a code sample.                Below is a traced Request/Response message.                                 Ø Second is through the IUpdatable Interface of WCF Data Services. In this method, you can first query the rule which you want to execute and then inserts Facts for that particular Rules and finally when you perform the SaveChanges() call for the IUpdatable Interface API, it executes the policy with the facts which you inserted at runtime. Below is a sample of client side code. Due to the limitations of current version of WCF Data Services where there is no way you can return back the updates happening on the service side back to the client via the SaveChanges() method. Here we are executing the rule passing a serialized XML as Facts and there is no changes made to any data where we can query back to fetch the changes. This is overcome though the first way to executing the policies which is by executing it as a Service Operation call.     This actually generates a AtomPub message shown as below:   POST /Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/$batch HTTP/1.1 User-Agent: Microsoft ADO.NET Data Services DataServiceVersion: 1.0;NetFx MaxDataServiceVersion: 2.0;NetFx Accept: application/atom+xml,application/xml Accept-Charset: UTF-8 Content-Type: multipart/mixed; boundary=batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Host: localhost:8080 Content-Length: 1481 Expect: 100-continue   --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Content-Type: multipart/mixed; boundary=changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf   --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf Content-Type: application/http Content-Transfer-Encoding: binary   MERGE http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy') HTTP/1.1 Content-ID: 4 Content-Type: application/atom+xml;type=entry Content-Length: 927   <?xml version="1.0" encoding="utf-8" standalone="yes"?> <entry xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" font-size: x-small"http://www.w3.org/2005/Atom">   <category scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" term="Tellago.BRE.REST.Resources.Fact" />   <title />   <author>     <name />   </author>   <updated>2011-01-31T20:09:15.0023982Z</updated>   <id>http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy')</id>   <content type="application/xml">     <m:properties>       <d:FactInstance>&lt;ns0:LoanStatus xmlns:ns0="http://tellago.com"&gt;&lt;Age&gt;10&lt;/Age&gt;&lt;Status&gt;true&lt;/Status&gt;&lt;/ns0:LoanStatus&gt;</d:FactInstance>       <d:FactType>TestSchema</d:FactType>       <d:ID>TestPolicy</d:ID>     </m:properties>   </content> </entry> --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf-- --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7—     Installation: The installation of the BRE Data Services is pretty straight forward. ·         Create a new IIS website say BREDataServices. ·         Download the SourceCode from TellagoCodeplex and copy the content from Tellago.BRE.REST.ServiceHost to the physical location of the above created website.     ·         The appPool account running the website should have admin access to the BizTalkRuleEngineDb database. ·         TheRight click the BREManagementService.svc in the IIS ContentView for the website and wala..     Conclusion: The BRE Data Services API is an experiment intended to bring the capabilities of RESTful/OData based services to the Traditional BTS/BRE Solutions. The future releases will target on technologies like BAM, ESB Toolkit. This version has been tested with various version of BizTalk Server and we have uploaded the source code to our Tellago's DevLabs workspace at Codeplex. I hope you guys enjoy this release. Keep an eye on our new releases @ Tellago Codeplex. We are working on various other Biztalk Artifacts like BAM, ESB Toolkit.     Till than happy BizzRuling…!!!     Thanks,   Vishal Mody

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• Best Practices - which domain types should be used to run applications

  - by jsavit

  This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains) One question that frequently comes up is "which types of domain should I use to run applications?" There used to be a simple answer in most cases: "only run applications in guest domains", but enhancements to T-series servers, Oracle VM Server for SPARC and the advent of SPARC SuperCluster have made this question more interesting and worth qualifying differently. This article reviews the relevant concepts and provides suggestions on where to deploy applications in a logical domains environment. Review: division of labor and types of domain Oracle VM Server for SPARC offloads many functions from the hypervisor to domains (also called virtual machines). This is a modern alternative to using a "thick" hypervisor that provides all virtualization functions, as in traditional VM designs, This permits a simpler hypervisor design, which enhances reliability, and security. It also reduces single points of failure by assigning responsibilities to multiple system components, which further improves reliability and security. In this architecture, management and I/O functionality are provided within domains. Oracle VM Server for SPARC does this by defining the following types of domain, each with their own roles: Control domain - management control point for the server, used to configure domains and manage resources. It is the first domain to boot on a power-up, is an I/O domain, and is usually a service domain as well. I/O domain - has been assigned physical I/O devices: a PCIe root complex, a PCI device, or a SR-IOV (single-root I/O Virtualization) function. It has native performance and functionality for the devices it owns, unmediated by any virtualization layer. Service domain - provides virtual network and disk devices to guest domains. Guest domain - a domain whose devices are all virtual rather than physical: virtual network and disk devices provided by one or more service domains. In common practice, this is where applications are run. Typical deployment A service domain is generally also an I/O domain: otherwise it wouldn't have access to physical device "backends" to offer to its clients. Similarly, an I/O domain is also typically a service domain in order to leverage the available PCI busses. Control domains must be I/O domains, because they boot up first on the server and require physical I/O. It's typical for the control domain to also be a service domain too so it doesn't "waste" the I/O resources it uses. A simple configuration consists of a control domain, which is also the one I/O and service domain, and some number of guest domains using virtual I/O. In production, customers typically use multiple domains with I/O and service roles to eliminate single points of failure: guest domains have virtual disk and virtual devices provisioned from more than one service domain, so failure of a service domain or I/O path or device doesn't result in an application outage. This is also used for "rolling upgrades" in which service domains are upgraded one at a time while their guests continue to operate without disruption. (It should be noted that resiliency to I/O device failures can also be provided by the single control domain, using multi-path I/O) In this type of deployment, control, I/O, and service domains are used for virtualization infrastructure, while applications run in guest domains. Changing application deployment patterns The above model has been widely and successfully used, but more configuration options are available now. Servers got bigger than the original T2000 class machines with 2 I/O busses, so there is more I/O capacity that can be used for applications. Increased T-series server capacity made it attractive to run more vertical applications, such as databases, with higher resource requirements than the "light" applications originally seen. This made it attractive to run applications in I/O domains so they could get bare-metal native I/O performance. This is leveraged by the SPARC SuperCluster engineered system, announced a year ago at Oracle OpenWorld. In SPARC SuperCluster, I/O domains are used for high performance applications, with native I/O performance for disk and network and optimized access to the Infiniband fabric. Another technical enhancement is the introduction of Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV), which make it possible to give domains direct connections and native I/O performance for selected I/O devices. A domain with either a DIO or SR-IOV device is an I/O domain. In summary: not all I/O domains own PCI complexes, and there are increasingly more I/O domains that are not service domains. They use their I/O connectivity for performance for their own applications. However, there are some limitations and considerations: at this time, a domain using physical I/O cannot be live-migrated to another server. There is also a need to plan for security and introducing unneeded dependencies: if an I/O domain is also a service domain providing virtual I/O go guests, it has the ability to affect the correct operation of its client guest domains. This is even more relevant for the control domain. where the ldm has to be protected from unauthorized (or even mistaken) use that would affect other domains. As a general rule, running applications in the service domain or the control domain should be avoided. To recap: Guest domains with virtual I/O still provide the greatest operational flexibility, including features like live migration. I/O domains can be used for applications with high performance requirements. This is used to great effect in SPARC SuperCluster and in general T4 deployments. Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV) make this more attractive by giving direct I/O access to more domains. Service domains should in general not be used for applications, because compromised security in the domain, or an outage, can affect other domains that depend on it. This concern can be mitigated by providing guests' their virtual I/O from more than one service domain, so an interruption of service in the service domain does not cause an application outage. The control domain should in general not be used to run applications, for the same reason. SPARC SuperCluster use the control domain for applications, but it is an exception: it's not a general purpose environment; it's an engineered system with specifically configured applications and optimization for optimal performance. These are recommended "best practices" based on conversations with a number of Oracle architects. Keep in mind that "one size does not fit all", so you should evaluate these practices in the context of your own requirements. Summary Higher capacity T-series servers have made it more attractive to use them for applications with high resource requirements. New deployment models permit native I/O performance for demanding applications by running them in I/O domains with direct access to their devices. This is leveraged in SPARC SuperCluster, and can be leveraged in T-series servers to provision high-performance applications running in domains. Carefully planned, this can be used to provide higher performance for critical applications.

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• HTG Explains: Why Does Rebooting a Computer Fix So Many Problems?

  - by Chris Hoffman

  Ask a geek how to fix a problem you’ve having with your Windows computer and they’ll likely ask “Have you tried rebooting it?” This seems like a flippant response, but rebooting a computer can actually solve many problems. So what’s going on here? Why does resetting a device or restarting a program fix so many problems? And why don’t geeks try to identify and fix problems rather than use the blunt hammer of “reset it”? This Isn’t Just About Windows Bear in mind that this soltion isn’t just limited to Windows computers, but applies to all types of computing devices. You’ll find the advice “try resetting it” applied to wireless routers, iPads, Android phones, and more. This same advice even applies to software — is Firefox acting slow and consuming a lot of memory? Try closing it and reopening it! Some Problems Require a Restart To illustrate why rebooting can fix so many problems, let’s take a look at the ultimate software problem a Windows computer can face: Windows halts, showing a blue screen of death. The blue screen was caused by a low-level error, likely a problem with a hardware driver or a hardware malfunction. Windows reaches a state where it doesn’t know how to recover, so it halts, shows a blue-screen of death, gathers information about the problem, and automatically restarts the computer for you . This restart fixes the blue screen of death. Windows has gotten better at dealing with errors — for example, if your graphics driver crashes, Windows XP would have frozen. In Windows Vista and newer versions of Windows, the Windows desktop will lose its fancy graphical effects for a few moments before regaining them. Behind the scenes, Windows is restarting the malfunctioning graphics driver. But why doesn’t Windows simply fix the problem rather than restarting the driver or the computer itself?  Well, because it can’t — the code has encountered a problem and stopped working completely, so there’s no way for it to continue. By restarting, the code can start from square one and hopefully it won’t encounter the same problem again. Examples of Restarting Fixing Problems While certain problems require a complete restart because the operating system or a hardware driver has stopped working, not every problem does. Some problems may be fixable without a restart, though a restart may be the easiest option. Windows is Slow: Let’s say Windows is running very slowly. It’s possible that a misbehaving program is using 99% CPU and draining the computer’s resources. A geek could head to the task manager and look around, hoping to locate the misbehaving process an end it. If an average user encountered this same problem, they could simply reboot their computer to fix it rather than dig through their running processes. Firefox or Another Program is Using Too Much Memory: In the past, Firefox has been the poster child for memory leaks on average PCs. Over time, Firefox would often consume more and more memory, getting larger and larger and slowing down. Closing Firefox will cause it to relinquish all of its memory. When it starts again, it will start from a clean state without any leaked memory. This doesn’t just apply to Firefox, but applies to any software with memory leaks. Internet or Wi-Fi Network Problems: If you have a problem with your Wi-Fi or Internet connection, the software on your router or modem may have encountered a problem. Resetting the router — just by unplugging it from its power socket and then plugging it back in — is a common solution for connection problems. In all cases, a restart wipes away the current state of the software . Any code that’s stuck in a misbehaving state will be swept away, too. When you restart, the computer or device will bring the system up from scratch, restarting all the software from square one so it will work just as well as it was working before. “Soft Resets” vs. “Hard Resets” In the mobile device world, there are two types of “resets” you can perform. A “soft reset” is simply restarting a device normally — turning it off and then on again. A “hard reset” is resetting its software state back to its factory default state. When you think about it, both types of resets fix problems for a similar reason. For example, let’s say your Windows computer refuses to boot or becomes completely infected with malware. Simply restarting the computer won’t fix the problem, as the problem is with the files on the computer’s hard drive — it has corrupted files or malware that loads at startup on its hard drive. However, reinstalling Windows (performing a “Refresh or Reset your PC” operation in Windows 8 terms) will wipe away everything on the computer’s hard drive, restoring it to its formerly clean state. This is simpler than looking through the computer’s hard drive, trying to identify the exact reason for the problems or trying to ensure you’ve obliterated every last trace of malware. It’s much faster to simply start over from a known-good, clean state instead of trying to locate every possible problem and fix it. Ultimately, the answer is that “resetting a computer wipes away the current state of the software, including any problems that have developed, and allows it to start over from square one.” It’s easier and faster to start from a clean state than identify and fix any problems that may be occurring — in fact, in some cases, it may be impossible to fix problems without beginning from that clean state. Image Credit: Arria Belli on Flickr, DeclanTM on Flickr     

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• CodePlex Daily Summary for Monday, August 11, 2014

  CodePlex Daily Summary for Monday, August 11, 2014Popular ReleasesSpace Engineers Server Manager: SESM V1.15: V1.15 - Updated Quartz library - Correct a bug in the new mod managment - Added a warning if you have backup enabled on a server but no static map configuredAspose for Apache POI: Missing Features of Apache POI SS - v 1.2: Release contain the Missing Features in Apache POI SS SDK in comparison with Aspose.Cells What's New ? Following Examples: Create Pivot Charts Detect Merged Cells Sort Data Printing Workbooks Feedback and Suggestions Many more examples are available at Aspose Docs. Raise your queries and suggest more examples via Aspose Forums or via this social coding site.AngularGo (SPA Project Template): AngularGo.VS2013.vsix: First ReleaseTouchmote: Touchmote 1.0 beta 13: Changes Less GPU usage Works together with other Xbox 360 controls Bug fixesPublic Key Infrastructure PowerShell module: PowerShell PKI Module v3.0: Important: I would like to hear more about what you are thinking about the project? I appreciate that you like it (2000 downloads over past 6 months), but may be you have to say something? What do you dislike in the module? Maybe you would love to see some new functionality? Tell, what you think! Installation guide:Use default installation path to install this module for current user only. To install this module for all users — enable "Install for all users" check-box in installation UI ...Modern UI for WPF: Modern UI 1.0.6: The ModernUI assembly including a demo app demonstrating the various features of Modern UI for WPF. BREAKING CHANGE LinkGroup.GroupName renamed to GroupKey NEW FEATURES Improved rendering on high DPI screens, including support for per-monitor DPI awareness available in Windows 8.1 (see also Per-monitor DPI awareness) New ModernProgressRing control with 8 builtin styles New LinkCommands.NavigateLink routed command New Visual Studio project templates 'Modern UI WPF App' and 'Modern UI W...ClosedXML - The easy way to OpenXML: ClosedXML 0.74.0: Multiple thread safe improvements including AdjustToContents XLHelper XLColor_Static IntergerExtensions.ToStringLookup Exception now thrown when saving a workbook with no sheets, instead of creating a corrupt workbook Fix for hyperlinks with non-ASCII Characters Added basic workbook protection Fix for error thrown, when a spreadsheet contained comments and images Fix to Trim function Fix Invalid operation Exception thrown when the formula functions MAX, MIN, and AVG referenc...SEToolbox: SEToolbox 01.042.019 Release 1: Added RadioAntenna broadcast name to ship name detail. Added two additional columns for Asteroid material generation for Asteroid Fields. Added Mass and Block number columns to main display. Added Ellipsis to some columns on main display to reduce name confusion. Added correct SE version number in file when saving. Re-added in reattaching Motor when drag/dropping or importing ships (KeenSH have added RotorEntityId back in after removing it months ago). Added option to export and r...jQuery List DragSort: jQuery List DragSort 0.5.2: Fixed scrollContainer removing deprecated use of $.browser so should now work with latest version of jQuery. Added the ability to return false in dragEnd to revert sort order Project changes Added nuget package for dragsort https://www.nuget.org/packages/dragsort Converted repository from SVN to MercurialBraintree Client Library: Braintree 2.32.0: Allow credit card verification options to be passed outside of the nonce for PaymentMethod.create Allow billingaddress parameters and billingaddress_id to be passed outside of the nonce for PaymentMethod.create Add Subscriptions to paypal accounts Add PaymentMethod.update Add failonduplicatepaymentmethod option to PaymentMethod.create Add support for dispute webhooksThe Mario Kart 8 App: V1.0.2.1: First Codeplex release. WINDOWS INSTALLER ONLYAspose Java for Docx4j: Aspose.Words vs Docx4j - v 1.0: Release contain the Code Comparison for Features in Docx4j SDK and Aspose.Words What's New ?Following Examples: Accessing Document Properties Add Bookmarks Convert to Formats Delete Bookmarks Working with Comments Feedback and Suggestions Many more examples are available at Aspose Docs. Raise your queries and suggest more examples via Aspose Forums or via this social coding site.File System Security PowerShell Module: NTFSSecurity 2.4.1: Add-Access and Remove-Access now take multiple accoutsYourSqlDba: YourSqlDba 5.2.1.: This version improves alert message that comes a while after you install the script. First it says to get it from YourSqlDba.CodePlex.com If you don't want to update now, just-rerun the script from your installed version. To get actual version running just execute install.PrintVersionInfo. . You can go to source code / history and click on change set 72957 to see changes in the script.Manipulator: Manipulator: manipulatorXNB filetype plugin for Paint.NET: Paint.NET XNB plugin v0.4.0.0: CHANGELOG Reverted old incomplete changes. Updated library for compatibility with Paint .NET 4. Updated project to NET 4.5. Updated version to 0.4.0.0. INSTALLATION INSTRUCTIONS Extract the ZIP file to your Paint.NET\FileTypes folder.EdiFabric: Release 4.1: Changed MessageContextWix# (WixSharp) - managed interface for WiX: Release 1.0.0.0: Release 1.0.0.0 Custom UI Custom MSI Dialog Custom CLR Dialog External UIMath.NET Numerics: Math.NET Numerics v3.2.0: Linear Algebra: Vector.Map2 (map2 in F#), storage-optimized Linear Algebra: fix RemoveColumn/Row early index bound check (was not strict enough) Statistics: Entropy ~Jeff Mastry Interpolation: use Array.BinarySearch instead of local implementation ~Candy Chiu Resources: fix a corrupted exception message string Portable Build: support .Net 4.0 as well by using profile 328 instead of 344. .Net 3.5: F# extensions now support .Net 3.5 as well .Net 3.5: NuGet package now contains pro...babelua: 1.6.5.1: V1.6.5.1 - 2014.8.7New feature: Formatting code; Stability improvement: fix a bug that pop up error "System.Net.WebResponse EndGetResponse";New ProjectsDouDou: a little project.Dynamic MVC: Dynamically generate views from your model objects for a data centric MVC application.EasyDb - Simple Data Access: EasyDb is a simple library for data access that allows you to write less code.ExpressToAbroad: just go!!!!!Full Silverlight Web Video/Voice Conferencing: The Goal of this project is to provide complete Open Source (Voice/Video Chatting Client/Server) Modules Using SilverlightGaia: Gaia is an app for Windows plataform, Gaia is like Siri and Google Now or Betty but Gaia use only text commands.pxctest: pxctestSTACS: Career Management System for MIT by Team "STACS"StrongWorld: StrongWorld.WebSuiteXevas Tools: Xevas is a professional coders group of 'Nimbuzz'. We make all tools for worldwide users of nimbuzz at free of cost.????????: ????????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ????????????????: ????????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ????????????????: ????????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ???????????????: ????????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ??????????????: ????????????????: ????????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ??????????????: ???????????????: ???????????????: ??????????????: ??????????????: ??????????????: ????????????????: ?????????

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• To SYNC or not to SYNC – Part 3

  - by AshishRay

  I can't believe it has been almost a year since my last blog post. I know, that's an absolute no-no in the blogosphere. And I know that "I have been busy" is not a good excuse. So - without trying to come up with an excuse - let me state this - my apologies for taking such a long time to write the next Part. Without further ado, here goes. This is Part 3 of a multi-part blog article where we are discussing various aspects of setting up Data Guard synchronous redo transport (SYNC). In Part 1 of this article, I debunked the myth that Data Guard SYNC is similar to a two-phase commit operation. In Part 2, I discussed the various ways that network latency may or may not impact a Data Guard SYNC configuration. In this article, I will talk in details regarding why Data Guard SYNC is a good thing. I will also talk about distance implications for setting up such a configuration. So, Why Good? Why is Data Guard SYNC a good thing? Because, at the end of the day, this gives you the assurance of zero data loss - it doesn’t matter what outage may befall your primary system. Befall! Boy, that sounds theatrical. But seriously - think about this - it minimizes your data risks. That’s a big deal. Whether you have an outage due to bad disks, faulty hardware components, hardware / software bugs, physical data corruptions, power failures, lightning that takes out significant part of your data center, fire that melts your assets, water leakage from the cooling system, human errors such as accidental deletion of online redo log files - it doesn’t matter - you can have that “Om - peace” look on your face and then you can failover to the standby system, without losing a single bit of data in your Oracle database. You will be a hero, as shown in this not so imaginary conversation: IT Manager: Well, what’s the status? You: John is doing the trace analysis on the storage array. IT Manager: So? How long is that gonna take? You: Well, he is stuck, waiting for a response from <insert your not-so-favorite storage vendor here>. IT Manager: So, no root cause yet? You: I told you, he is stuck. We have escalated with their Support, but you know how long these things take. IT Manager: Darn it - the site is down! You: Not really … IT Manager: What do you mean? You: John is stuck, but Sreeni has already done a failover to the Data Guard standby. IT Manager: Whoa, whoa - wait! Failover means we lost some data, why did you do this without letting the Business group know? You: We didn’t lose any data. Remember, we had set up Data Guard with SYNC? So now, any problems on the production – we just failover. No data loss, and we are up and running in minutes. The Business guys don’t need to know. IT Manager: Wow! Are we great or what!! You: I guess … Ok, so you get it - SYNC is good. But as my dear friend Larry Carpenter says, “TANSTAAFL”, or "There ain't no such thing as a free lunch". Yes, of course - investing in Data Guard SYNC means that you have to invest in a low-latency network, you have to monitor your applications and database especially in peak load conditions, and you cannot under-provision your standby systems. But all these are good and necessary things, if you are supporting mission-critical apps that are supposed to be running 24x7. The peace of mind that this investment will give you is priceless, especially if you are serious about HA. How Far Can We Go? Someone may say at this point - well, I can’t use Data Guard SYNC over my coast-to-coast deployment. Most likely - true. So how far can you go? Well, we have customers who have deployed Data Guard SYNC over 300+ miles! Does this mean that you can also deploy over similar distances? Duh - no! I am going to say something here that most IT managers don’t like to hear - “It depends!” It depends on your application design, application response time / throughput requirements, network topology, etc. However, because of the optimal way we do SYNC, customers have been able to stretch Data Guard SYNC deployments over longer distances compared to traditional, storage-centric ways of doing this. The MAA Database 10.2 best practices paper Data Guard Redo Transport & Network Configuration, and Oracle Database 11.2 High Availability Best Practices Manual talk about some of these SYNC-related metrics. For example, a test deployment of Data Guard SYNC over 330 miles with 10ms latency showed an impact less than 5% for a busy OLTP application. Even if you can’t deploy Data Guard SYNC over your WAN distance, or if you already have an ASYNC standby located 1000-s of miles away, here’s another nifty way to boost your HA. Have a local standby, configured SYNC. How local is “local”? Again - it depends. One customer runs a local SYNC standby across the campus. Another customer runs it across 15 miles in another data center. Both of these customers are running Data Guard SYNC as their HA standard. If a localized outage affects their primary system, no problem! They have all the data available on the standby, to which they can failover. Very fast. In seconds. Wait - did I say “seconds”? Yes, Virginia, there is a Santa Claus. But you have to wait till the next blog article to find out more. I assure you tho’ that this time you won’t have to wait for another year for this.

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• DTracing TCP congestion control

  - by user12820842

  In a previous post, I showed how we can use DTrace to probe TCP receive and send window events. TCP receive and send windows are in effect both about flow-controlling how much data can be received - the receive window reflects how much data the local TCP is prepared to receive, while the send window simply reflects the size of the receive window of the peer TCP. Both then represent flow control as imposed by the receiver. However, consider that without the sender imposing flow control, and a slow link to a peer, TCP will simply fill up it's window with sent segments. Dealing with multiple TCP implementations filling their peer TCP's receive windows in this manner, busy intermediate routers may drop some of these segments, leading to timeout and retransmission, which may again lead to drops. This is termed congestion, and TCP has multiple congestion control strategies. We can see that in this example, we need to have some way of adjusting how much data we send depending on how quickly we receive acknowledgement - if we get ACKs quickly, we can safely send more segments, but if acknowledgements come slowly, we should proceed with more caution. More generally, we need to implement flow control on the send side also. Slow Start and Congestion Avoidance From RFC2581, let's examine the relevant variables: "The congestion window (cwnd) is a sender-side limit on the amount of data the sender can transmit into the network before receiving an acknowledgment (ACK). Another state variable, the slow start threshold (ssthresh), is used to determine whether the slow start or congestion avoidance algorithm is used to control data transmission" Slow start is used to probe the network's ability to handle transmission bursts both when a connection is first created and when retransmission timers fire. The latter case is important, as the fact that we have effectively lost TCP data acts as a motivator for re-probing how much data the network can handle from the sending TCP. The congestion window (cwnd) is initialized to a relatively small value, generally a low multiple of the sending maximum segment size. When slow start kicks in, we will only send that number of bytes before waiting for acknowledgement. When acknowledgements are received, the congestion window is increased in size until cwnd reaches the slow start threshold ssthresh value. For most congestion control algorithms the window increases exponentially under slow start, assuming we receive acknowledgements. We send 1 segment, receive an ACK, increase the cwnd by 1 MSS to 2*MSS, send 2 segments, receive 2 ACKs, increase the cwnd by 2*MSS to 4*MSS, send 4 segments etc. When the congestion window exceeds the slow start threshold, congestion avoidance is used instead of slow start. During congestion avoidance, the congestion window is generally updated by one MSS for each round-trip-time as opposed to each ACK, and so cwnd growth is linear instead of exponential (we may receive multiple ACKs within a single RTT). This continues until congestion is detected. If a retransmit timer fires, congestion is assumed and the ssthresh value is reset. It is reset to a fraction of the number of bytes outstanding (unacknowledged) in the network. At the same time the congestion window is reset to a single max segment size. Thus, we initiate slow start until we start receiving acknowledgements again, at which point we can eventually flip over to congestion avoidance when cwnd ssthresh. Congestion control algorithms differ most in how they handle the other indication of congestion - duplicate ACKs. A duplicate ACK is a strong indication that data has been lost, since they often come from a receiver explicitly asking for a retransmission. In some cases, a duplicate ACK may be generated at the receiver as a result of packets arriving out-of-order, so it is sensible to wait for multiple duplicate ACKs before assuming packet loss rather than out-of-order delivery. This is termed fast retransmit (i.e. retransmit without waiting for the retransmission timer to expire). Note that on Oracle Solaris 11, the congestion control method used can be customized. See here for more details. In general, 3 or more duplicate ACKs indicate packet loss and should trigger fast retransmit . It's best not to revert to slow start in this case, as the fact that the receiver knew it was missing data suggests it has received data with a higher sequence number, so we know traffic is still flowing. Falling back to slow start would be excessive therefore, so fast recovery is used instead. Observing slow start and congestion avoidance The following script counts TCP segments sent when under slow start (cwnd ssthresh). #!/usr/sbin/dtrace -s #pragma D option quiet tcp:::connect-request / start[args[1]-cs_cid] == 0/ { start[args[1]-cs_cid] = 1; } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd tcps_cwnd_ssthresh / { @c["Slow start", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd args[3]-tcps_cwnd_ssthresh / { @c["Congestion avoidance", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } As we can see the script only works on connections initiated since it is started (using the start[] associative array with the connection ID as index to set whether it's a new connection (start[cid] = 1). From there we simply differentiate send events where cwnd ssthresh (congestion avoidance). Here's the output taken when I accessed a YouTube video (where rport is 80) and from an FTP session where I put a large file onto a remote system. # dtrace -s tcp_slow_start.d ^C ALGORITHM RADDR RPORT #SEG Slow start 10.153.125.222 20 6 Slow start 138.3.237.7 80 14 Slow start 10.153.125.222 21 18 Congestion avoidance 10.153.125.222 20 1164 We see that in the case of the YouTube video, slow start was exclusively used. Most of the segments we sent in that case were likely ACKs. Compare this case - where 14 segments were sent using slow start - to the FTP case, where only 6 segments were sent before we switched to congestion avoidance for 1164 segments. In the case of the FTP session, the FTP data on port 20 was predominantly sent with congestion avoidance in operation, while the FTP session relied exclusively on slow start. For the default congestion control algorithm - "newreno" - on Solaris 11, slow start will increase the cwnd by 1 MSS for every acknowledgement received, and by 1 MSS for each RTT in congestion avoidance mode. Different pluggable congestion control algorithms operate slightly differently. For example "highspeed" will update the slow start cwnd by the number of bytes ACKed rather than the MSS. And to finish, here's a neat oneliner to visually display the distribution of congestion window values for all TCP connections to a given remote port using a quantization. In this example, only port 80 is in use and we see the majority of cwnd values for that port are in the 4096-8191 range. # dtrace -n 'tcp:::send { @q[args[4]-tcp_dport] = quantize(args[3]-tcps_cwnd); }' dtrace: description 'tcp:::send ' matched 10 probes ^C 80 value ------------- Distribution ------------- count -1 | 0 0 |@@@@@@ 5 1 | 0 2 | 0 4 | 0 8 | 0 16 | 0 32 | 0 64 | 0 128 | 0 256 | 0 512 | 0 1024 | 0 2048 |@@@@@@@@@ 8 4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@ 23 8192 | 0

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