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  • Training a 'replacement', how to enforce standards?

    - by Mohgeroth
    Not sure that this is the right stack exchange site to ask this of, but here goes... Scope I work for a small company that employs a few hundred people. The development team for the company is small and works out of visual foxpro. A specific department in the company hired me in as a 'lone gunman' to fix and enhance a pre-existing invoicing system. I've successfully taken an Access application that suffered from a lot of risks and limitations and converted it into a C# application driven off of a SQL server backend. I have recently obtained my undergraduate and am no expert by any means. To help make up for that I've felt that earning microsoft certifications will force me to understand more about .net and how it functions. So, after giving my notice with 9 months in advance, 3 months ago a replacement finally showed up. Their role is to learn what I have been designing to an attempt to support the applications designed in C#. The Replacement Fresh out of college with no real-world work experience, the first instinct for anything involving data was and still is listboxes... any time data is mentioned the list box is the control of choice for the replacement. This has gotten to the point, no matter how many times I discuss other controls, where I've seen 5 listboxes on a single form. Classroom experience was almost all C++ console development. So, an example of where I have concern is in a winforms application: Users need to key Reasons into a table to select from later. Given that I know that a strongly typed data set exists, I can just drag the data source from the toolbox and it would create all of this for me. I realize this is a simple example but using databinding is the key. For the past few months now we have been talking about the strongly typed dataset, how to use it and where it interacts with other controls. Data sets, how they work in relation to binding sources, adapters and data grid views. After handing this project off I expected questions about how to implement these since for me this is the way to do it. What happened next simply floors me: An instance of an adapter from the strongly typed dataset was created in the activate event of the form, a table was created and filled with data. Then, a loop was made to manually add rows to a listbox from this table. Finally, a variable was kept to do lookups to figure out what ID the record was for updates if required. How do they modify records you ask? That was my first question too. You won't believe how simple it is, all you do it double click and they type into a pop-up prompt the new value to change it to. As a data entry operator, all the modal popups would drive me absolutely insane. The final solution exceeds 100 lines of code that must be maintained. So my concern is that none of this is sinking in... the department is only allowed 20 hours a week of their time. Up until last week, we've only been given 4-5 hours a week if I'm lucky. The past week or so, I've been lucky to get 10. Question WHAT DO I DO?! I have 4 weeks left until I leave and they fully 'support' this application. I love this job and the opportunity it has given me but it's time for me to spread my wings and find something new. I am in no way, shape or form convinced that they are ready to take over. I do feel that the replacement has the technical ability to 'figure it out' but instead of learning they just write code to do all of this stuff manually. If the replacement wants to code differently in the end, as long as it works I'm fine with that as horrifiying at it looks. However to support what I have designed they MUST to understand how it works and how I have used controls and the framework to make 'magic' happen. This project has about 40 forms, a database with over 30 some odd tables, triggers and stored procedures. It relates labor to invoices to contracts to projections... it's not as simple as it was three years ago when I began this project and the department is now in a position where they cannot survive without it. How in the world can I accomplish any of the following?: Enforce standards or understanding in constent design when the department manager keeps telling them they can do it however they want to Find a way to engage the replacement in active learning of the framework and system design that support must be given for Gracefully inform sr. management that 5-9 hours a week is simply not enough time to learn about the department, pre-existing processes, applications that need to be supported AND determine where potential enhancements to the system go... Yes I know this is a wall of text, thanks for reading through me but I simply don't know what I should be doing. For me, this job is a monster of a reference and things would look extremely bad if I left and things fell apart. How do I handle this?

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  • XBRL - Moving from Production to Consumption

    - by jmorourke
    Here's an update on what’s new with XBRL and how it can actually benefit your organization versus adding extra time and costs to financial reporting.  On February 29th (leap day) of 2012 I attended the XBRL and Financial Analysis Technology Conference at Baruch College in NYC.  The event, which attracted over 300 XBRL gurus and fans was presented by XBRL US, The New York Society of Security Analysts’ Improved Corporate Reporting Committee, and Baruch College’s Robert Zicklin Center for Corporate Integrity.  The event featured keynotes from the U.S. Securities and Exchange Commission (SEC), and the CFA Institute as well as panels covering alternative research tools and data, corporate reporting to stakeholders and a demonstration of XBRL analysis tools.  The program culminated in a presentation of the finalists and the winner of the $20,000 XBRL Challenge.    Some of the key points made in the sessions included: The focus of XBRL tools is moving from production to consumption. As of February 2012, over 9000 companies are reporting in XBRL, with over 10 million facts filed to date XBRL taxonomy extensions have dropped from 27% to 11% making comparisons easier The SEC reports that XBRL makes it easier to analyze disclosures, focus on accounting issues XBRL is helping standards-setters like the FASB speed their analysis of impacts of proposed accounting rule changes Companies like Thomson Reuters report that XBRL is helping speed the delivery of data to clients The most interesting part of the program though, was the session highlighting the 5 finalists in the XBRL Challenge competition and the winning solution.  The XBRL Challenge was launched in 2011 as a means of spurring the development of more end-user tools to help with the consumption of XBRL-based financial information.       Over an 8-month process handled by 5 judges, there were 84 registrants, 15 completed submissions, 5 finalists and one winner of the challenge.  All of the solutions are open-sourced tools and most of them focus on consuming XBRL-based data.  The 5 finalists included: Advanced XBRL Processing from Oxide solutions – XBRL viewer for taxonomies, filings and company data with peer comparison capabilities. Arrelle – API for XBRL processes, supports SEC Validations, RSS Feeds to access filings etc. Calcbench – XBRL data analysis tool that can be embedded in other web applications.  This tool can combine XBRL filings with real-time market data. XBRL to XL – allows the importing of XBRL data into Microsoft Excel for analysis, comparisons.  Users start on the web and populate Excel with XBRL data. XBurble – allows users to search and view XBRL filings, export to Excel, merge for comparison, and includes a workflow interface. The winner of the $20,000 XBRL Challenge prize was CalcBench.  More information about the XBRL Challenge and the finalists can be found at www.XBRLUS.org/challenge XBRL for Sustainability Reporting – other recent news on the XBRL front was the announcement by the Global Reporting Initiative (GRI) of an XBRL taxonomy for Sustainability Reporting.  This taxonomy was co-developed by the GRI and Deloitte and is designed to make the consumption of data found in Sustainability Reports much easier.  Although there is no government mandate to file Sustainability Reports in XBRL format, organizations that do use the GRI guidelines for Sustainability Reporting are encouraged to tag and submit their data voluntarily to the GRI – who will populate a database with Sustainability Reporting data and make this available to the public.  For more information about this initiative, you can go to the GRI web site:  www.globalreporting.org. So how does all of this benefit corporate filers and investors?  Since its introduction, the consensus in the market is that XBRL has mainly benefited the regulators and investment analysts who need to consume and analyze large volumes of financial data.  But with the emergence of more end-user tools for consuming and analyzing XBRL-based data, and the ability to perform quick comparisons of one company versus its peers and competitors in an industry group, will soon accelerate the benefits to corporate finance staff, as well as individual investors.  This could apply to financial results tagged in XBRL, as well as non-financial information such as Sustainability Reporting – which over the long-term will likely be integrated with financial reporting.   And as multiple regulators and agencies in a country adopt the XBRL standard for corporate filings, more benefits will accrue as companies will be able to leverage one set of XBRL-based financial data for multiple regulatory filings.     For more information about the latest developments in XBRL, check out the XBRL US or XBRL International web sites:  www.xbrl.org, www.xbrlus.org. For more information about what Oracle is doing to support XBRL, here are some links: http://www.oracle.com/us/solutions/ent-performance-bi/disclosure-management-065892.html http://www.oracle.com/technetwork/database/features/xmldb/index-087631.html Feel free to contact me if you have any questions or need more information:  [email protected]

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  • AppHarbor - Azure Done Right AKA Heroku for .NET

    - by Robz / Fervent Coder
    Easy and Instant deployments and instant scale for .NET? Awhile back a few of us were looking at Ruby Gems as the answer to package management for .NET. The gems platform supported the concept of DLLs as packages although some changes would have needed to happen to have long term use for the entire community. From that we formed a partnership with some folks at Microsoft to make v2 into something that would meet wider adoption across the community, which people now call NuGet. So now we have the concept of package management. What comes next? Heroku Instant deployments and instant scaling. Stupid simple API. This is Heroku. It doesn’t sound like much, but when you think of how fast you can go from an idea to having someone else tinker with it, you can start to see its power. In literally seconds you can be looking at your rails application deployed and online. Then when you are ready to scale, you can do that. This is power. Some may call this “cloud-computing” or PaaS (Platform as a Service). I first ran into Heroku back in July when I met Nick of RubyGems.org. At the time there was no alternative in the .NET-o-sphere. I don’t count Windows Azure, mostly because it is not simple and I don’t believe there is a free version. Heroku itself would not lend itself well to .NET due to the nature of platforms and each language’s specific needs (solution stack).  So I tucked the idea in the back of my head and moved on. AppHarbor Enters The Scene I’m not sure when I first heard about AppHarbor as a possible .NET version of Heroku. It may have been in November, but I didn’t actually try it until January. I was instantly hooked. AppHarbor is awesome! It still has a ways to go to be considered Heroku for .NET, but it already has a growing community. I created a video series (at the bottom of this post) that really highlights how fast you can get a product onto the web and really shows the power and simplicity of AppHarbor. Deploying is as simple as a git/hg push to appharbor. From there they build your code, run any unit tests you have and deploy it if everything succeeds. The screen on the right shows a simple and elegant UI to getting things done. The folks at AppHarbor graciously gave me a limited number of invites to hand out. If you are itching to try AppHarbor then navigate to: https://appharbor.com/account/new?inviteCode=ferventcoder  After playing with it, send feedback if you want more features. Go vote up two features I want that will make it more like Heroku. Disclaimer: I am in no way affiliated with AppHarbor and have not received any funds or favors from anyone at AppHarbor. I just think it is awesome and I want others to know about it. From Zero To Deployed in 15 Minutes (Or Less) Now I have a challenge for you. I created a video series showing how fast I could go from nothing to a deployed application. It could have been from Zero to Deployed in Less than 5 minutes, but I wanted to show you the tools a little more and give you an opportunity to beat my time. And that’s the challenge. Beat my time and show it in a video response. The video series is below (at least one of the videos has to be watched on YouTube). The person with the best time by March 15th @ 11:59PM CST will receive a prize. Ground rules: .NET Application with a valid database connection Start from Zero Deployed with AppHarbor or an alternative A timer displayed in the video that runs during the entire process Video response published on YouTube or acceptable alternative Video(s) must be published by March 15th at 11:59PM CST. Either post the link here as a comment or on YouTube as a response (also by 11:59PM CST March 15th) From Zero To Deployed In 15 Minutes (Or Less) Part 1 From Zero To Deployed In 15 Minutes (Or Less) Part 2 From Zero To Deployed In 15 Minutes (Or Less) Part 3

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  • Cannot connect to Open WiFi hotspot created by Android

    - by Bibhas
    I'm trying to share my 3G data connection via WiFi hotspot. I have an open Hotspot running on my phone(Xperia Neo V - MT11i - Android 2.3.4). But I cannot connect to it from my Ubuntu system. Here is the syslog while I try to connect to it - NetworkManager[1077]: <info> Activation (wlan0) starting connection 'TheNeo' NetworkManager[1077]: <info> (wlan0): device state change: disconnected -> prepare (reason 'none') [30 40 0] NetworkManager[1077]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled... NetworkManager[1077]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started... NetworkManager[1077]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled... NetworkManager[1077]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete. NetworkManager[1077]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting... NetworkManager[1077]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0] NetworkManager[1077]: <info> Activation (wlan0/wireless): connection 'TheNeo' requires no security. No secrets needed. NetworkManager[1077]: <info> Config: added 'ssid' value 'TheNeo' NetworkManager[1077]: <info> Config: added 'scan_ssid' value '1' NetworkManager[1077]: <info> Config: added 'key_mgmt' value 'NONE' NetworkManager[1077]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete. NetworkManager[1077]: <info> Config: set interface ap_scan to 1 NetworkManager[1077]: <info> (wlan0): supplicant interface state: inactive -> scanning wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) NetworkManager[1077]: <info> (wlan0): supplicant interface state: scanning -> authenticating kernel: [17498.113553] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17498.310138] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17498.510069] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17498.710083] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17504.779927] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17504.976420] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17505.176379] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17505.376314] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17511.478385] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17511.674738] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17511.874655] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17512.074659] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17518.152643] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17518.349064] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17518.549051] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17518.748999] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17524.858896] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17525.055404] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17525.255387] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17525.455254] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17531.589176] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17531.785747] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17531.985724] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17532.185610] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17538.329257] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17538.528003] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17538.728024] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17538.927922] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17545.022036] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17545.218339] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17545.418319] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17545.618206] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out wpa_supplicant[29352]: Trying to authenticate with 5c:b5:24:2f:d1:2f (SSID='TheNeo' freq=2462 MHz) kernel: [17551.724177] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 1/3) kernel: [17551.920685] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 2/3) kernel: [17552.120597] wlan0: direct probe to 5c:b5:24:2f:d1:2f (try 3/3) kernel: [17552.320526] wlan0: direct probe to 5c:b5:24:2f:d1:2f timed out NetworkManager[1077]: <warn> Activation (wlan0/wireless): association took too long, failing activation. NetworkManager[1077]: <info> (wlan0): device state change: config -> failed (reason 'supplicant-timeout') [50 120 11] NetworkManager[1077]: <warn> Activation (wlan0) failed for access point (TheNeo) NetworkManager[1077]: <warn> Activation (wlan0) failed. NetworkManager[1077]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0] NetworkManager[1077]: <info> (wlan0): deactivating device (reason 'none') [0] NetworkManager[1077]: <info> (wlan0): supplicant interface state: authenticating -> disconnected NetworkManager[1077]: <warn> Couldn't disconnect supplicant interface: This interface is not connected. Why is direct probe to 5c:b5:24:2f:d1:2f timed out? Any idea?

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  • .NET Code Evolution

    - by Alois Kraus
    Originally posted on: http://geekswithblogs.net/akraus1/archive/2013/07/24/153504.aspxAt my day job I do look at a lot of code written by other people. Most of the code is quite good and some is even a masterpiece. And there is also code which makes you think WTF… oh it was written by me. Hm not so bad after all. There are many excuses reasons for bad code. Most often it is time pressure followed by not enough ambition (who cares) or insufficient training. Normally I do care about code quality quite a lot which makes me a (perceived) slow worker who does write many tests and refines the code quite a lot because of the design deficiencies. Most of the deficiencies I do find by putting my design under stress while checking for invariants. It does also help a lot to step into the code with a debugger (sometimes also Windbg). I do this much more often when my tests are red. That way I do get a much better understanding what my code really does and not what I think it should be doing. This time I do want to show you how code can evolve over the years with different .NET Framework versions. Once there was  time where .NET 1.1 was new and many C++ programmers did switch over to get rid of not initialized pointers and memory leaks. There were also nice new data structures available such as the Hashtable which is fast lookup table with O(1) time complexity. All was good and much code was written since then. At 2005 a new version of the .NET Framework did arrive which did bring many new things like generics and new data structures. The “old” fashioned way of Hashtable were coming to an end and everyone used the new Dictionary<xx,xx> type instead which was type safe and faster because the object to type conversion (aka boxing) was no longer necessary. I think 95% of all Hashtables and dictionaries use string as key. Often it is convenient to ignore casing to make it easy to look up values which the user did enter. An often followed route is to convert the string to upper case before putting it into the Hashtable. Hashtable Table = new Hashtable(); void Add(string key, string value) { Table.Add(key.ToUpper(), value); } This is valid and working code but it has problems. First we can pass to the Hashtable a custom IEqualityComparer to do the string matching case insensitive. Second we can switch over to the now also old Dictionary type to become a little faster and we can keep the the original keys (not upper cased) in the dictionary. Dictionary<string, string> DictTable = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); void AddDict(string key, string value) { DictTable.Add(key, value); } Many people do not user the other ctors of Dictionary because they do shy away from the overhead of writing their own comparer. They do not know that .NET has for strings already predefined comparers at hand which you can directly use. Today in the many core area we do use threads all over the place. Sometimes things break in subtle ways but most of the time it is sufficient to place a lock around the offender. Threading has become so mainstream that it may sound weird that in the year 2000 some guy got a huge incentive for the idea to reduce the time to process calibration data from 12 hours to 6 hours by using two threads on a dual core machine. Threading does make it easy to become faster at the expense of correctness. Correct and scalable multithreading can be arbitrarily hard to achieve depending on the problem you are trying to solve. Lets suppose we want to process millions of items with two threads and count the processed items processed by all threads. A typical beginners code might look like this: int Counter; void IJustLearnedToUseThreads() { var t1 = new Thread(ThreadWorkMethod); t1.Start(); var t2 = new Thread(ThreadWorkMethod); t2.Start(); t1.Join(); t2.Join(); if (Counter != 2 * Increments) throw new Exception("Hmm " + Counter + " != " + 2 * Increments); } const int Increments = 10 * 1000 * 1000; void ThreadWorkMethod() { for (int i = 0; i < Increments; i++) { Counter++; } } It does throw an exception with the message e.g. “Hmm 10.222.287 != 20.000.000” and does never finish. The code does fail because the assumption that Counter++ is an atomic operation is wrong. The ++ operator is just a shortcut for Counter = Counter + 1 This does involve reading the counter from a memory location into the CPU, incrementing value on the CPU and writing the new value back to the memory location. When we do look at the generated assembly code we will see only inc dword ptr [ecx+10h] which is only one instruction. Yes it is one instruction but it is not atomic. All modern CPUs have several layers of caches (L1,L2,L3) which try to hide the fact how slow actual main memory accesses are. Since cache is just another word for redundant copy it can happen that one CPU does read a value from main memory into the cache, modifies it and write it back to the main memory. The problem is that at least the L1 cache is not shared between CPUs so it can happen that one CPU does make changes to values which did change in meantime in the main memory. From the exception you can see we did increment the value 20 million times but half of the changes were lost because we did overwrite the already changed value from the other thread. This is a very common case and people do learn to protect their  data with proper locking.   void Intermediate() { var time = Stopwatch.StartNew(); Action acc = ThreadWorkMethod_Intermediate; var ar1 = acc.BeginInvoke(null, null); var ar2 = acc.BeginInvoke(null, null); ar1.AsyncWaitHandle.WaitOne(); ar2.AsyncWaitHandle.WaitOne(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Intermediate did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Intermediate() { for (int i = 0; i < Increments; i++) { lock (this) { Counter++; } } } This is better and does use the .NET Threadpool to get rid of manual thread management. It does give the expected result but it can result in deadlocks because you do lock on this. This is in general a bad idea since it can lead to deadlocks when other threads use your class instance as lock object. It is therefore recommended to create a private object as lock object to ensure that nobody else can lock your lock object. When you read more about threading you will read about lock free algorithms. They are nice and can improve performance quite a lot but you need to pay close attention to the CLR memory model. It does make quite weak guarantees in general but it can still work because your CPU architecture does give you more invariants than the CLR memory model. For a simple counter there is an easy lock free alternative present with the Interlocked class in .NET. As a general rule you should not try to write lock free algos since most likely you will fail to get it right on all CPU architectures. void Experienced() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Experienced); t1.Wait(); t2.Wait(); if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Experienced did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Experienced() { for (int i = 0; i < Increments; i++) { Interlocked.Increment(ref Counter); } } Since time does move forward we do not use threads explicitly anymore but the much nicer Task abstraction which was introduced with .NET 4 at 2010. It is educational to look at the generated assembly code. The Interlocked.Increment method must be called which does wondrous things right? Lets see: lock inc dword ptr [eax] The first thing to note that there is no method call at all. Why? Because the JIT compiler does know very well about CPU intrinsic functions. Atomic operations which do lock the memory bus to prevent other processors to read stale values are such things. Second: This is the same increment call prefixed with a lock instruction. The only reason for the existence of the Interlocked class is that the JIT compiler can compile it to the matching CPU intrinsic functions which can not only increment by one but can also do an add, exchange and a combined compare and exchange operation. But be warned that the correct usage of its methods can be tricky. If you try to be clever and look a the generated IL code and try to reason about its efficiency you will fail. Only the generated machine code counts. Is this the best code we can write? Perhaps. It is nice and clean. But can we make it any faster? Lets see how good we are doing currently. Level Time in s IJustLearnedToUseThreads Flawed Code Intermediate 1,5 (lock) Experienced 0,3 (Interlocked.Increment) Master 0,1 (1,0 for int[2]) That lock free thing is really a nice thing. But if you read more about CPU cache, cache coherency, false sharing you can do even better. int[] Counters = new int[12]; // Cache line size is 64 bytes on my machine with an 8 way associative cache try for yourself e.g. 64 on more modern CPUs void Master() { var time = Stopwatch.StartNew(); Task t1 = Task.Factory.StartNew(ThreadWorkMethod_Master, 0); Task t2 = Task.Factory.StartNew(ThreadWorkMethod_Master, Counters.Length - 1); t1.Wait(); t2.Wait(); Counter = Counters[0] + Counters[Counters.Length - 1]; if (Counter != 2 * Increments) throw new Exception(String.Format("Hmm {0:N0} != {1:N0}", Counter, 2 * Increments)); Console.WriteLine("Master did take: {0:F1}s", time.Elapsed.TotalSeconds); } void ThreadWorkMethod_Master(object number) { int index = (int) number; for (int i = 0; i < Increments; i++) { Counters[index]++; } } The key insight here is to use for each core its own value. But if you simply use simply an integer array of two items, one for each core and add the items at the end you will be much slower than the lock free version (factor 3). Each CPU core has its own cache line size which is something in the range of 16-256 bytes. When you do access a value from one location the CPU does not only fetch one value from main memory but a complete cache line (e.g. 16 bytes). This means that you do not pay for the next 15 bytes when you access them. This can lead to dramatic performance improvements and non obvious code which is faster although it does have many more memory reads than another algorithm. So what have we done here? We have started with correct code but it was lacking knowledge how to use the .NET Base Class Libraries optimally. Then we did try to get fancy and used threads for the first time and failed. Our next try was better but it still had non obvious issues (lock object exposed to the outside). Knowledge has increased further and we have found a lock free version of our counter which is a nice and clean way which is a perfectly valid solution. The last example is only here to show you how you can get most out of threading by paying close attention to your used data structures and CPU cache coherency. Although we are working in a virtual execution environment in a high level language with automatic memory management it does pay off to know the details down to the assembly level. Only if you continue to learn and to dig deeper you can come up with solutions no one else was even considering. I have studied particle physics which does help at the digging deeper part. Have you ever tried to solve Quantum Chromodynamics equations? Compared to that the rest must be easy ;-). Although I am no longer working in the Science field I take pride in discovering non obvious things. This can be a very hard to find bug or a new way to restructure data to make something 10 times faster. Now I need to get some sleep ….

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  • C#/.NET Little Wonders: Getting Caller Information

    - by James Michael Hare
    Originally posted on: http://geekswithblogs.net/BlackRabbitCoder/archive/2013/07/25/c.net-little-wonders-getting-caller-information.aspx Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. There are times when it is desirable to know who called the method or property you are currently executing.  Some applications of this could include logging libraries, or possibly even something more advanced that may server up different objects depending on who called the method. In the past, we mostly relied on the System.Diagnostics namespace and its classes such as StackTrace and StackFrame to see who our caller was, but now in C# 5, we can also get much of this data at compile-time. Determining the caller using the stack One of the ways of doing this is to examine the call stack.  The classes that allow you to examine the call stack have been around for a long time and can give you a very deep view of the calling chain all the way back to the beginning for the thread that has called you. You can get caller information by either instantiating the StackTrace class (which will give you the complete stack trace, much like you see when an exception is generated), or by using StackFrame which gets a single frame of the stack trace.  Both involve examining the call stack, which is a non-trivial task, so care should be done not to do this in a performance-intensive situation. For our simple example let's say we are going to recreate the wheel and construct our own logging framework.  Perhaps we wish to create a simple method Log which will log the string-ified form of an object and some information about the caller.  We could easily do this as follows: 1: static void Log(object message) 2: { 3: // frame 1, true for source info 4: StackFrame frame = new StackFrame(1, true); 5: var method = frame.GetMethod(); 6: var fileName = frame.GetFileName(); 7: var lineNumber = frame.GetFileLineNumber(); 8: 9: // we'll just use a simple Console write for now 10: Console.WriteLine("{0}({1}):{2} - {3}", 11: fileName, lineNumber, method.Name, message); 12: } So, what we are doing here is grabbing the 2nd stack frame (the 1st is our current method) using a 2nd argument of true to specify we want source information (if available) and then taking the information from the frame.  This works fine, and if we tested it out by calling from a file such as this: 1: // File c:\projects\test\CallerInfo\CallerInfo.cs 2:  3: public class CallerInfo 4: { 5: Log("Hello Logger!"); 6: } We'd see this: 1: c:\projects\test\CallerInfo\CallerInfo.cs(5):Main - Hello Logger! This works well, and in fact CallStack and StackFrame are still the best ways to examine deeper into the call stack.  But if you only want to get information on the caller of your method, there is another option… Determining the caller at compile-time In C# 5 (.NET 4.5) they added some attributes that can be supplied to optional parameters on a method to receive caller information.  These attributes can only be applied to methods with optional parameters with explicit defaults.  Then, as the compiler determines who is calling your method with these attributes, it will fill in the values at compile-time. These are the currently supported attributes available in the  System.Runtime.CompilerServices namespace": CallerFilePathAttribute – The path and name of the file that is calling your method. CallerLineNumberAttribute – The line number in the file where your method is being called. CallerMemberName – The member that is calling your method. So let’s take a look at how our Log method would look using these attributes instead: 1: static int Log(object message, 2: [CallerMemberName] string memberName = "", 3: [CallerFilePath] string fileName = "", 4: [CallerLineNumber] int lineNumber = 0) 5: { 6: // we'll just use a simple Console write for now 7: Console.WriteLine("{0}({1}):{2} - {3}", 8: fileName, lineNumber, memberName, message); 9: } Again, calling this from our sample Main would give us the same result: 1: c:\projects\test\CallerInfo\CallerInfo.cs(5):Main - Hello Logger! However, though this seems the same, there are a few key differences. First of all, there are only 3 supported attributes (at this time) that give you the file path, line number, and calling member.  Thus, it does not give you as rich of detail as a StackFrame (which can give you the calling type as well and deeper frames, for example).  Also, these are supported through optional parameters, which means we could call our new Log method like this: 1: // They're defaults, why not fill 'em in 2: Log("My message.", "Some member", "Some file", -13); In addition, since these attributes require optional parameters, they cannot be used in properties, only in methods. These caveats aside, they do let you get similar information inside of methods at a much greater speed!  How much greater?  Well lets crank through 1,000,000 iterations of each.  instead of logging to console, I’ll return the formatted string length of each.  Doing this, we get: 1: Time for 1,000,000 iterations with StackTrace: 5096 ms 2: Time for 1,000,000 iterations with Attributes: 196 ms So you see, using the attributes is much, much faster!  Nearly 25x faster in fact.  Summary There are a few ways to get caller information for a method.  The StackFrame allows you to get a comprehensive set of information spanning the whole call stack, but at a heavier cost.  On the other hand, the attributes allow you to quickly get at caller information baked in at compile-time, but to do so you need to create optional parameters in your methods to support it. Technorati Tags: Little Wonders,CSharp,C#,.NET,StackFrame,CallStack,CallerFilePathAttribute,CallerLineNumberAttribute,CallerMemberName

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  • Intel Centrino Wireless-N 1000 Again ! Ubuntu 13.04 x64

    - by vafa
    First I have to say that I tried everything written about this concept. The problem is that it stops working randomly in 3 main forms : 1 - sometimes it disconnect from wireless network and reconnect automatically 2 - sometimes it disconnect and wont connect no matter what (needs reboot) 3 - some times it's still connected but cannot ping or surf or whatever. I already tried disabling N mod using these commands : sudo modprobe -r iwlwifi modprobe iwlwifi 11n_disable=1 (or 0, whatever) it didn't help . these are the results of lspci, sudo lshw -C network, ifconfig, iwconfig, rfkill list when it disconnected and didn't connect till reboot : ifconfig : eth0 Link encap:Ethernet HWaddr c8:0a:a9:34:65:77 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:1563213476557380 errors:9379306629148050 dropped:3126435543049350 overruns:1563217771524675 frame:7816088857623375 TX packets:1563217771524675 errors:6252871086098700 dropped:0 overruns:1563217771524675 carrier:3126435543049350 collisions:7816088857623375 txqueuelen:1000 RX bytes:1563217771524675 (1.5 PB) TX bytes:1563217771524675 (1.5 PB) ham0 Link encap:Ethernet HWaddr 7a:79:19:a5:e4:93 inet addr:25.165.228.147 Bcast:25.255.255.255 Mask:255.0.0.0 inet6 addr: fe80::7879:19ff:fea5:e493/64 Scope:Link inet6 addr: 2620:9b::19a5:e493/96 Scope:Global UP BROADCAST RUNNING MULTICAST MTU:1404 Metric:1 RX packets:7743 errors:0 dropped:0 overruns:0 frame:0 TX packets:1250 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:665642 (665.6 KB) TX bytes:204056 (204.0 KB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:41138 errors:0 dropped:0 overruns:0 frame:0 TX packets:41138 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:6420962 (6.4 MB) TX bytes:6420962 (6.4 MB) wlan0 Link encap:Ethernet HWaddr 00:1e:64:45:fb:70 inet6 addr: fe80::21e:64ff:fe45:fb70/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:286999 errors:0 dropped:0 overruns:0 frame:0 TX packets:226966 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:324386887 (324.3 MB) TX bytes:30674804 (30.6 MB) iwconfig : ham0 no wireless extensions. eth0 no wireless extensions. lo no wireless extensions. wlan0 IEEE 802.11bg ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=14 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off sudo lshw -C network: *-network description: Wireless interface product: Centrino Wireless-N 1000 [Condor Peak] vendor: Intel Corporation physical id: 0 bus info: pci@0000:07:00.0 logical name: wlan0 version: 00 serial: 00:1e:64:45:fb:70 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=3.8.0-30-generic firmware=39.31.5.1 build 35138 latency=0 link=no multicast=yes wireless=IEEE 802.11bg resources: irq:46 memory:c0400000-c0401fff *-network description: Ethernet interface product: AR8131 Gigabit Ethernet vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:09:00.0 logical name: eth0 version: c0 serial: c8:0a:a9:34:65:77 capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vpd cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.1-NAPI latency=0 link=no multicast=yes port=twisted pair resources: irq:47 memory:c0900000-c093ffff ioport:5000(size=128) *-network description: Ethernet interface physical id: 2 logical name: ham0 serial: 7a:79:19:a5:e4:93 size: 10Mbit/s capabilities: ethernet physical configuration: autonegotiation=off broadcast=yes driver=tun driverversion=1.6 duplex=full ip=25.165.228.147 link=yes multicast=yes port=twisted pair speed=10Mbit/s lspci: 00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07) 00:01.0 PCI bridge: Intel Corporation Mobile 4 Series Chipset PCI Express Graphics Port (rev 07) 00:1a.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 03) 00:1a.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 03) 00:1a.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 03) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03) 00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 03) 00:1c.3 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 4 (rev 03) 00:1c.5 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 6 (rev 03) 00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 03) 00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 03) 00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 03) 00:1d.3 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 03) 00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 03) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 93) 00:1f.0 ISA bridge: Intel Corporation ICH9M LPC Interface Controller (rev 03) 00:1f.2 SATA controller: Intel Corporation 82801IBM/IEM (ICH9M/ICH9M-E) 4 port SATA Controller [AHCI mode] (rev 03) 00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 03) 01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 105M] (rev a1) 07:00.0 Network controller: Intel Corporation Centrino Wireless-N 1000 [Condor Peak] 09:00.0 Ethernet controller: Qualcomm Atheros AR8131 Gigabit Ethernet (rev c0) rfkill list : 1: acer-wireless: Wireless LAN Soft blocked: no Hard blocked: no 2: acer-bluetooth: Bluetooth Soft blocked: yes Hard blocked: no 9: phy0: Wireless LAN Soft blocked: no Hard blocked: no any help will be REALLLYYYY appreciated

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  • Airline mess - what a journey

    - by Mike Dietrich
    What a day, what a journey ... Flew this noon from Munich to Zuerich for catch my ongoing flight to San Francisco with Swiss. And that day did start very well as Lufthansa messed up the connection flight by 42 minutes for a 35 minute flight. And as I was obviously the only passenger connection to San Francisco nobody picked me up at the airplane to bring me directly to my connection as Swiss did for the 8 passengers connection to Miami. So I missed my flight. What a start - and many thanks to Lufthansa. I was not the only one missing a connection as Lufthansa/Swiss had canceled the flight before due to "technical problems". In Zuerich Swiss did rebook me via Frankfurt with Lufthansa to board a United Airlines flight to San Francisco. "Ouch" I thought. I had my share of experience with United already as they've messed up my luggage on the way to San Francisco some years ago and it took them five (!!!) days to fly my bag over and deliver it. But actually it was the only option today. So I said "Yes". A big mistake as I've learned later on. The Frankfurt flight was delayed as well "due to a late incoming aircraft". But there was plenty of time. And I went to the Swiss counter at the gate and let them check if my baggage is on that flight to Frankfurt. They've said "Yes". Boarding the plane with a delay of 45 minutes (the typical Lufthansa delay these days) I spotted my Rimowa trolley right next to the plane on the airfield. So I was sure that it will be send to Frankfurt. In Frankfurt I went to the United counter once it did open - had to go through the passport check they do for US flights as well - and they've said "Yes, your luggage is with us". Well ... Arriving in San Francisco with just a bit of a some minutes delay and a very fast immigration procedure I saw the first bags with Priority tags getting pushed to the baggage claim - but mine was not there. I did wait ... and wait ... and wait. Well, thanks United, you did it again!!! I flew twice in the past years United Airlines - and in both cases they've messed up my luggage on the way to San Francisco. How lovely is that ... Now the real fun started again as the lady at the "Lost and Found" counter for luggage spotted my luggage in her system in Zuerich - and told me it's supposed to be sent with LH1191 to Frankfurt on Sept 27. But this was yesterday in Europe - it's already Sept 28 - and I saw my luggage in front of the airplane. So I'd suppose it's in Frankfurt already. But what could she do? Nothing but doing the awful paperwork. And "No Mr Dietrich, we don't call international numbers". Thank you, United. Next time I'll try to get a contract for a US land line in advance. They can't even tell you which plane will bring your luggage. It may be tomorrow with UA flight arriving around 4pm in SFO. I'm looking forward to some hours in the wonderful United Airlines call center waiting line. Last time I did spend 60-90 minutes every day until I got my luggage. If it takes again that long then OOW will be over by then. I love airline travel - and especially with United Airlines. And by the way ... they gave us these nice fancy packages during the flight:  That looks good - what's in that box??? Yes, really ... a bag of potato chips. Pure fat - very healthy.  I doubt that I'll ever fly United Airlines again!!!

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  • 24 Hours of PASS – first reflections

    - by Rob Farley
    A few days after the end of 24HOP, I find myself reflecting on it. I’m still waiting on most of the information. I want to be able to discover things like where the countries represented on each of the sessions, and things like that. So far, I have the feedback scores and the numbers of attendees. The data was provided in a PDF, so while I wait for it to appear in a more flexible format, I’ve pushed the 24 attendee numbers into Excel. This chart shows the numbers by time. Remember that we started at midnight GMT, which was 10:30am in my part of the world and 8pm in New York. It’s probably no surprise that numbers drooped a bit at the start, stayed comparatively low, and then grew as the larger populations of the English-speaking world woke up. I remember last time 24HOP ran for 24 hours straight, there were quite a few sessions with less than 100 attendees. None this time though. We got close, but even when it was 4am in New York, 8am in London and 7pm in Sydney (which would have to be the worst slot for attracting people), we still had over 100 people tuning in. As expected numbers grew as the UK woke up, and even more so as the US did, with numbers peaking at 755 for the “3pm in New York” session on SQL Server Data Tools. Kendra Little almost reached those numbers too, and certainly contributed the biggest ‘spike’ on the chart with her session five hours earlier. Of all the sessions, Kendra had the highest proportion of ‘Excellent’s for the “Overall Evaluation of the session” question, and those of you who saw her probably won’t be surprised by that. Kendra had one of the best ranked sessions from the 24HOP event this time last year (narrowly missing out on being top 3), and she has produced a lot of good video content since then. The reports indicate that there were nearly 8.5 thousand attendees across the 24 sessions, averaging over 350 at each one. I’m looking forward to seeing how many different people that was, although I do know that Wil Sisney managed to attend every single one (if you did too, please let me know). Wil even moderated one of the sessions, which made his feat even greater. Thanks Wil. I also want to send massive thanks to Dave Dustin. Dave probably would have attended all of the sessions, if it weren’t for a power outage that forced him to take a break. He was also a moderator, and it was during this session that he earned special praise. Part way into the session he was moderating, the speaker lost connectivity and couldn’t get back for about fifteen minutes. That’s an incredibly long time when you’re in a live presentation. There were over 200 people tuned in at the time, and I’m sure Dave was as stressed as I was to have a speaker disappear. I started chasing down a phone number for the speaker, while Dave spoke to the audience. And he did brilliantly. He started answering questions, and kept doing that until the speaker came back. Bear in mind that Dave hadn’t expected to give a presentation on that topic (or any other), and was simply drawing on his SQL expertise to get him through. Also consider that this was between midnight at 1am in Dave’s part of the world (Auckland, NZ). I would’ve been expecting just to welcome people, monitor questions, probably read some out, and in general, help make things run smoothly. He went far beyond the call of duty, and if I had a medal to give him, he’d definitely be getting one. On the whole, I think this 24HOP was a success. We tried a different platform, and I think for the most part it was a popular move. We didn’t ask the question “Was this better than LiveMeeting?”, but we did get a number of people telling us that they thought the platform was very good. Some people have told me I get a chance to put my feet up now that this is over. As I’m also co-ordinating a tour of SQLSaturday events across the Australia/New Zealand region, I don’t quite get to take that much of a break (plus, there’s the little thing of squeezing in seven SQL 2012 exams over the next 2.5 weeks). But I am pleased to be reflecting on this event rather than anticipating it. There were a number of factors that could have gone badly, but on the whole I’m pleased about how it went. A massive thanks to everyone involved. If you’re reading this and thinking you wish you could’ve tuned in more, don’t worry – they were all recorded and you’ll be able to watch them on demand very soon. But as well as that, PASS has a stream of content produced by the Virtual Chapters, so you can keep learning from the comfort of your desk all year round. More info on them at sqlpass.org, of course.

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  • How to move MOSS 2007 to another SharePoint Farm

    - by DipeshBhanani
    It was time of my first onsite client assignment on SharePoint. Client had one server production environment. They wanted to upgrade the topology with completely new SharePoint Farm of three servers. So, the task was to move whole MOSS 2007 stuff to the new server environment without impacting data. The last three words “… without impacting data…” were actually putting pressure on my head. Moreover SSP was required to move because additional information has been added for users apart from AD import.   I thought I had to do only backup and restore. It appeared pretty easy at first thought. Just because of these three damn scary words, I thought to check out on internet for guidance related to this scenario. I couldn’t get anything except general guidance of moving server on Microsoft TechNet site. I promised myself for starting blogs with this post if I would be successful in this task. Well, I took long time to write this but finally made it. I hope it will be useful to all guys looking for SharePoint server movement.   Before beginning restoration, make sure that, there is no difference in versions of SharePoint at source and destination server. Also check whether the state of SharePoint Installation at the time of backup and restore is same or not. (E.g. SharePoint related service packs and patches if any)   The main tasks of the server movement are as follow:   1.        Backup all the databases 2.        Install and configure SharePoint on new environment 3.        Deploy all solutions (WSP Files) globally to destination server- for installing features attached to the solutions 4.        Install all the custom features 5.        Deploy/Copy custom pages/files which are added to the “12Hive” folder later 6.        Restore SSP 7.        Restore My Site 8.        Restore other web application   Tasks 3 to 5 are for making sure that we have configured the environment well enough for the web application to be restored successfully. The main and complex task was restoring SSP. I have started restoring SSP through Central Admin. After a while, the restoration status was updated to “unsuccessful”. “Damn it, what went wrong?” I thought looking at the error detail down the page. I couldn’t remember the error message but I had corrected and restored it again.   Actually once you fail restoring SSP, until and unless you don’t clean all related stuff well, your restoration will be failed again and again. I wanted to find the actual reason. So cleaned, restored, cleaned, restored… I had tried almost 5-6 times and finally, I succeeded. I had realized how pleasant it is, to see the word “Successful” on the screen. Without wasting your much time to read, let me write all the detailed steps of restoring SSP:   1.        Delete the SSP through following STSADM command. stsadm -o deletessp -title <SSP name> -deletedatabases -force e.g.: stsadm -o deletessp -title SharedServices1 -deletedatabases –force 2.        Check and delete the web application associated with SSP if it exists. 3.        Remove Link from Check and remove “Alternate Access Mapping” associated with SSP if it exists. 4.        Check and delete IIS site as well as application pool associated with SSP if it exists. 5.        Stop following services: ·         Office SharePoint Server Search ·         Windows SharePoint Services Search ·         Windows SharePoint Services Help Search   6.        Delete all the databases associated/related to SSP from SQL Server. 7.        Reset IIS. 8.        Start again following services: ·         Office SharePoint Server Search ·         Windows SharePoint Services Search ·         Windows SharePoint Services Help Search   9.        Restore the new SSP.   After the SSP restoration, all other stuffs had completed very smoothly without any more issues. I did few modifications to sites for change of server name and finally, the new environment was ready.

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  • Keep a programming language backwards compatible vs. fixing its flaws

    - by Radu Murzea
    First, some context (stuff that most of you know anyway): Every popular programming language has a clear evolution, most of the time marked by its version: you have Java 5, 6, 7 etc., PHP 5.1, 5.2, 5.3 etc. Releasing a new version makes new APIs available, fixes bugs, adds new features, new frameworks etc. So all in all: it's good. But what about the language's (or platform's) problems? If and when there's something wrong in a language, developers either avoid it (if they can) or they learn to live with it. Now, the developers of those languages get a lot of feedback from the programmers that use them. So it kind of makes sense that, as time (and version numbers) goes by, the problems in those languages will slowly but surely go away. Well, not really. Why? Backwards compatibility, that's why. But why is this so? Read below for a more concrete situation. The best way I can explain my question is to use PHP as an example: PHP is loved thousands of people and hated by just as many thousands. All languages have flaws, but apparently PHP is special. Check out this blog post. It has a very long list of so called flaws in PHP. Now, I'm not a PHP developer (not yet), but I read through all of it and I'm sure that a big chunk of that list are indeed real issues. (Not all of it, since it's potentially subjective). Now, if I was one of the guys who actively develops PHP, I would surely want to fix those problems, one by one. However, if I do that, then code that relies on a particular behaviour of the language will break if it runs on the new version. Summing it up in 2 words: backwards compatibility. What I don't understand is: why should I keep PHP backwards compatible? If I release PHP version 8 with all those problems fixed, can't I just put a big warning on it saying: "Don't run old code on this version !"? There is a thing called deprecation. We had it for years and it works. In the context of PHP: look at how these days people actively discourage the use of the mysql_* functions (and instead recommend mysqli_* and PDO). Deprecation works. We can use it. We should use it. If it works for functions, why shouldn't it work for entire languages? Let's say I (the developer of PHP) do this: Launch a new version of PHP (let's say 8) with all of those flaws fixed New projects will start using that version, since it's much better, clearer, more secure etc. However, in order not to abandon older versions of PHP, I keep releasing updates to it, fixing security issues, bugs etc. This makes sense for reasons that I'm not listing here. It's common practice: look for example at how Oracle kept updating version 5.1.x of MySQL, even though it mostly focused on version 5.5.x. After about 3 or 4 years, I stop updating old versions of PHP and leave them to die. This is fine, since in those 3 or 4 years, most projects will have switched to PHP 8 anyway. My question is: Do all these steps make sense? Would it be so hard to do? If it can be done, then why isn't it done? Yes, the downside is that you break backwards compatibility. But isn't that a price worth paying ? As an upside, in 3 or 4 years you'll have a language that has 90 % of its problems fixed.... a language much more pleasant to work with. Its name will ensure its popularity. EDIT: OK, so I didn't expressed myself correctly when I said that in 3 or 4 years people will move to the hypothetical PHP 8. What I meant was: in 3 or 4 years, people will use PHP 8 if they start a new project.

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  • Use your own domain email and tired of SPAM? SPAMfighter FTW

    - by Dave Campbell
    I wouldn't post this if I hadn't tried it... and I paid for it myself, so don't anybody be thinking I'm reviewing something someone sent me! Long ago and far away I got very tired of local ISPs and 2nd phone lines and took the plunge and got hooked up to cable... yeah I know the 2nd phone line concept may be hard for everyone to understand, but that's how it was in 'the old days'. To avoid having to change email addresses all the time, I decided to buy a domain name, get minimal hosting, and use that for all email into the house. That way if I changed providers, all the email addresses wouldn't have to change. Of course, about a dozen domains later, I have LOTS of pop email addresses and even an exchange address to my client's server... times have changed. What also has changed is the fact that we get SPAM... 'back in the day' when I was a beta tester for the first ISP in Phoenix, someone tried sending an ad to all of us, and what he got in return for his trouble was a bunch of core dumps that locked up his email... if you don't know what a core dump is, ask your grandfather. But in today's world, we're all much more civilized than that, and as with many things, the criminals seem to have much more rights than we do, so we get inundated with email offering all sorts of wild schemes that you'd have to be brain-dead to accept, but yet... if people weren't accepting them, they'd stop sending them. I keep hoping that survival of the smartest would weed out the mental midgets that respond and then the jumk email stop, but that hasn't happened yet anymore than finding high-quality hearing aids at the checkout line of Safeway because of all the dimwits playing music too loud inside their car... but that's another whole topic and I digress. So what's the solution for all the spam? And I mean *all*... on that old personal email address, I am now getting over 150 spam messages a day! Yes I know that's why God invented the delete key, but I took it on as a challenge, and it's a matter of principle... why should I switch email addresses, or convert from [email protected] to something else, or have all my email filtered through some service just because some A-Hole somewhere has a site up trying to phish Ma & Pa Kettle (ask your grandfather about that too) out of their retirement money? Well... I got an email from my cousin the other day while I was writing yet another email rule, and there was a banner on the bottom of his email that said he was protected by SPAMfighter. SPAMfighter huh.... so I took a look at their site, and found yet one more of the supposed tools to help us. But... I read that they're a Microsoft Gold Partner... and that doesn't come lightly... so I took a gamble and here's what I found: I installed it, and had to do a couple things: 1) SPAMfighter stuffed the SPAMfighter folder into my client's exchange address... I deleted it, made a new SPAMfighter folder where I wanted it to go, then in the SPAMfighter Clients settings for Outlook, I told it to put all spam there. 2) It didn't seem to be doing anything. There's a ribbon button that you can select "Block", and I did that, wondering if I was 'training' it, but it wasn't picking up duplicates 3) I sent email to support, and wrote a post on the forum (not to self: reply to that post). By the time the folks from the home office responded, it was the next day, and first up, SPAMfighter knocked down everything that came through when Outlook opend... two thumbs up! I disabled my 'garbage collection' rule from Outlook, and told Outlook not to use the junk folder thinking it was interfering. 4) Day 2 seemed to go about like Day 1... but I hung in there. 5) Day 3 is now a whole new day... I had left Outlook open and hadn't looked at the PC since sometime late yesterday afternoon, and when I looked this morning, *every bit* of spam was in the SPAMfighter folder!! I'm a new paying customer After watching SPAMfighter work this morning, I've purchased a 1-year license, and I now can sit and watch as emails come in and disappear from my inbox into the SPAMfighter folder. No more continual tweaking of the rules. I've got SPAMfighter set to 'Very Hard' filtering... personally I'd rather pull the few real emails out of the SPAMfighter folder than pull spam out of the real folders. Yes this is simply another way of using the delete key, but you know what? ... it feels good :) Here's a screenshot of the stats after just about 48 hours of being onboard: Note that all the ones blocked by me were during Day 1 and 2... I've blocked none today, and everything is blocked. Stay in the 'Light!

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  • Agile Testing Days 2012 – My First Conference!

    - by Chris George
    I’d like to give you a bit of background first… so please bear with me! In 1996, whilst studying for my final year of my degree, I applied for a job as a C++ Developer at a small software house in Hertfordshire  After bodging up the technical part of the interview I didn’t get the job, but was offered a position as a QA Engineer instead. The role sounded intriguing and the pay was pretty good so in the absence of anything else I took it. Here began my career in the world of software testing! Back then, testing/QA was often an afterthought, something that was bolted on to the development process and very much a second class citizen. Test automation was rare, and tools were basic or non-existent! The internet was just starting to take off, and whilst there might have been testing communities and resources, we were certainly not exposed to any of them. After 8 years I moved to another small company, and again didn’t find myself exposed to any of the changes that were happening in the industry. It wasn’t until I joined Red Gate in 2008 that my view of testing and software development as a whole started to expand. But it took a further 4 years for my view of testing to be totally blown open, and so the story really begins… In May 2012 I was fortunate to land the role of Head of Test Engineering. Soon after, I received an email with details for the “Agile Testi However, in my new role, I decided that it was time to bite the bullet and at least go to one conference. Perhaps I could get some new ideas to supplement and support some of the ideas I already had.ng Days” conference in Potsdam, Germany. I looked over the suggested programme and some of the talks peeked my interest. For numerous reasons I’d shied away from attending conferences in the past, one of the main ones being that I didn’t see much benefit in attending loads of talks when I could just read about stuff like that on the internet. So, on the 18th November 2012, myself and three other Red Gaters boarded a plane at Heathrow bound for Potsdam, Germany to attend Agile Testing Days 2012. Tutorial Day – “Software Testing Reloaded” We chose to do the tutorials on the 19th, I chose the one titled “Software Testing Reloaded – So you wanna actually DO something? We’ve got just the workshop for you. Now with even less powerpoint!”. With such a concise and serious title I just had to see what it was about! I nervously entered the room to be greeted by tables, chairs etc all over the place, not set out and frankly in one hell of a mess! There were a few people in there playing a game with dice. Okaaaay… this is going to be a long day! Actually the dice game was an exercise in deduction and simplification… I found it very interesting and is certainly something I’ll be using at work as a training exercise! (I won’t explain the game here cause I don’t want to let the cat out of the bag…) The tutorial consisted of several games, exploring different aspects of testing. They were all practical yet required a fair amount of thin king. Matt Heusser and Pete Walen were running the tutorial, and presented it in a very relaxed and light-hearted manner. It was really my first experience of working in small teams with testers from very different backgrounds, and it was really enjoyable. Matt & Pete were very approachable and offered advice where required whilst still making you work for the answers! One of the tasks was to devise several strategies for testing some electronic dice. The premise was that a Vegas casino wanted to use the dice to appeal to the twenty-somethings interested in tech, but needed assurance that they were as reliable and random as traditional dice. This was a very interesting and challenging exercise that forced us to challenge various assumptions, determine/clarify requirements but most of all it was frustrating because the dice made a very very irritating beeping noise. Multiple that by at least 12 dice and I was dreaming about them all that night!! Some of the main takeaways that were brilliantly demonstrated through the games were not to make assumptions, challenge requirements, and have fun testing! The tutorial lasted the whole day, but to be honest the day went very quickly! My introduction into the conference experience started very well indeed, and I would talk to both Matt and Pete several times during the 4 days. Days 1,2 & 3 will be coming soon…  

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  • Microsoft Forcing Dev/Partners Hands on Win 8 Through Certification

    - by D'Arcy Lussier
    I remember 2.5 years ago when Microsoft dropped a bomb on the Microsoft Partner community: all Gold competencies would require .NET 4 based premiere certifications (MCPD). Problem was, this gave a window of about 6 months for partners to update their employees’ certifications. At the place I was working, I put together an aggressive plan and we were able to attain the certs needed. Microsoft is always open that the certification requirements will change as the industry changes. .NET 1.0 certifications are useless here in 2012, and rightfully so they’ve been retired for a long time now. But now we’re seeing a new tactic by Microsoft – shifting gears away from certifications that speak to what industry needs and more to the Windows 8 agenda. Consider that currently the premiere development certification is the Microsoft Certified Professional Developer, which comes in three flavours – Web, Windows, and Azure. All require WCF and Data Access exams, as well as one that deals with the associated base technologies (ASP.NET, WinForms/WPF, Azure), and one that ties all three together in a solution-based exam. For Microsoft-based organizations, these skills aren’t just valid but necessary in building Microsoft applications. But the MCPD is being replaced with our old friend Microsoft Certified Solutions Developer (MCSD). So far, Microsoft has only released two types of MCSD – Web and Windows Store Apps. Windows Store Apps?! In a push to move developers to create WinRT-based applications, desktop development is now considered a second-class citizen in the eyes of Redmond. Also interesting are the language options for the exams: HTML5 and C#. Sorry VB folks, its time to embrace curly braces whether they be JavaScript or C#. Consider too the skills being assessed for the Windows Store Apps: Get your MCSD: Windows Store Apps Using HTML5 Get your MCSD: Windows Store Apps Using C# *Image Source: http://www.microsoft.com/learning/en/us/certification/mcsd-windows-store-apps.aspx Nov 21/2012 If you look at the skills being tested in each exam, you’ll find that skills like WCF and Data Access are downplayed compared to things like integrating Charms, facilitating Search, programming for the microphone and camera – all very Windows 8 focussed items. Where this becomes maddening is that Microsoft is still pushing Windows 7 with enterprise clients. According to a ZDNet article, Microsoft wants to see Windows 7 on 70% of enterprise desktops by mid 2013. Assuming they somehow meet that (its a pretty lofty goal), there’s years of traditional desktop-based development that will still be required at some level. For those thinking they’ll just write and stick with the MCPD certification, note that most exams that go towards that certification will be retired at the end of July 2013! (Read the small print). And while details haven’t been finalized, its a safe bet that MCPD certifications eventually won’t count towards Gold-level competencies in the Microsoft Partner program. What this means for Microsoft Partners and Developers is that certification for desktop development is going to be limited to Windows Store Apps unless Microsoft re-introduces a traditional desktop (WPF) based MCSD cert. Web Application Development – It’s Not All Bad There’s big changes on the web side of certification, but I actually see these changes as being for the good! Check out the new exam requirements for MCSD – Web Applications: Get your MCSD: Web Applications certification *Image Source: http://www.microsoft.com/learning/en/us/certification/cert-mcsd-web-applications.aspx Nov 21, 2012 We now *start* with HTML5, JavaScript, and CSS3! Now I’m sure that these will be slanted towards web development in IE, and I can hear designers everywhere bemoaning the CSS/IE combination. Still, I applaud Microsoft for adopting HTML5 as the go-to web technology and requiring certified developers to prove they have skills in the basics of web dev. The fact that the second exam clearly states “MVC Web Applications” shows that Web Forms is truly legacy and deprecated. That’s not to say there aren’t those out there that are still supporting or (for whatever reason) doing new dev with Web Forms, but this move by Microsoft is telling the community they better get on the MVC bandwagon if they want to stay current. Fantastic! And of course Azure needs to be here as well, and this is where the Microsoft agenda fits in. It’s no secret that there’s been a huge push in getting developers on to Azure. I don’t see this as being a bad thing either, as cloud computing (whether Azure, private, or 3rd party) is a necessary skill for developers to have here in 2012. The cynic in me realizes that the HTML5/JavaScript/CSS push wouldn’t be as prominent though if not for the Windows 8 Store App play, where HTML5 is a first class citizen (and an available language for the MCSD Windows Store App cert). In this case, the desktop developers loss is the web developers gain. Get Ready for Changes In addition to the changes in certifications, the Microsoft Partner competencies are going through changes as well. Web and Software Development are being merged into a single competency, meaning that licenses you would have received from having both as Gold are reduced. Other competencies are either being removed or changed, as are the exam requirements. In the same way that we’re seeing faster release cycles from Microsoft, so too will we see the Microsoft Partner Program and MS Certifications evolve faster than ever before. Many of us got caught in the last wave of changes, but this time we can see the wave coming – and it looks pretty big!

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  • Thread.Interrupt Is Evil

    - by Alois Kraus
    Recently I have found an interesting issue with Thread.Interrupt during application shutdown. Some application was crashing once a week and we had not really a clue what was the issue. Since it happened not very often it was left as is until we have got some memory dumps during the crash. A memory dump usually means WindDbg which I really like to use (I know I am one of the very few fans of it).  After a quick analysis I did find that the main thread already had exited and the thread with the crash was stuck in a Monitor.Wait. Strange Indeed. Running the application a few thousand times under the debugger would potentially not have shown me what the reason was so I decided to what I call constructive debugging. I did create a simple Console application project and try to simulate the exact circumstances when the crash did happen from the information I have via memory dump and source code reading. The thread that was  crashing was actually MS code from an old version of the Microsoft Caching Application Block. From reading the code I could conclude that the main thread did call the Dispose method on the CacheManger class which did call Thread.Interrupt on the cache scavenger thread which was just waiting for work to do. My first version of the repro looked like this   static void Main(string[] args) { Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); } static void ThreadFunc() { while (true) { object value = Dequeue(); // block until unblocked or awaken via ThreadInterruptedException } } static object WaitObject = new object(); static object Dequeue() { object lret = "got value"; try { lock (WaitObject) { } } catch (ThreadInterruptedException) { Console.WriteLine("Got ThreadInterruptException"); lret = null; } return lret; } I do start a background thread and call Thread.Interrupt on it and then directly let the application terminate. The thread in the meantime does plenty of Monitor.Enter/Leave calls to simulate work on it. This first version did not crash. So I need to dig deeper. From the memory dump I did know that the finalizer thread was doing just some critical finalizers which were closing file handles. Ok lets add some long running finalizers to the sample. class FinalizableObject : CriticalFinalizerObject { ~FinalizableObject() { Console.WriteLine("Hi we are waiting to finalize now and block the finalizer thread for 5s."); Thread.Sleep(5000); } } class Program { static void Main(string[] args) { FinalizableObject fin = new FinalizableObject(); Thread t = new Thread(ThreadFunc) { IsBackground = true, Name = "Test Thread" }; t.Start(); Console.WriteLine("Interrupt Thread"); t.Interrupt(); GC.KeepAlive(fin); // prevent finalizing it too early // After leaving main the other thread is woken up via Thread.Abort // while we are finalizing. This causes a stackoverflow in the CLR ThreadAbortException handling at this time. } With this changed Main method and a blocking critical finalizer I did get my crash just like the real application. The funny thing is that this is actually a CLR bug. When the main method is left the CLR does suspend all threads except the finalizer thread and declares all objects as garbage. After the normal finalizers were called the critical finalizers are executed to e.g. free OS handles (usually). Remember that I did call Thread.Interrupt as one of the last methods in the Main method. The Interrupt method is actually asynchronous and does wake a thread up and throws a ThreadInterruptedException only once unlike Thread.Abort which does rethrow the exception when an exception handling clause is left. It seems that the CLR does not expect that a frozen thread does wake up again while the critical finalizers are executed. While trying to raise a ThreadInterrupedException the CLR goes down with an stack overflow. Ups not so nice. Why has this nobody noticed for years is my next question. As it turned out this error does only happen on the CLR for .NET 4.0 (x86 and x64). It does not show up in earlier or later versions of the CLR. I have reported this issue on connect here but so far it was not confirmed as a CLR bug. But I would be surprised if my console application was to blame for a stack overflow in my test thread in a Monitor.Wait call. What is the moral of this story? Thread.Abort is evil but Thread.Interrupt is too. It is so evil that even the CLR of .NET 4.0 contains a race condition during the CLR shutdown. When the CLR gurus can get it wrong the chances are high that you get it wrong too when you use this constructs. If you do not believe me see what Patrick Smacchia does blog about Thread.Abort and List.Sort. Not only the CLR creators can get it wrong. The BCL writers do sometimes have a hard time with correct exception handling as well. If you do tell me that you use Thread.Abort frequently and never had problems with it I do suspect that you do not have looked deep enough into your application to find such sporadic errors.

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  • Drive Online Engagement with Intuitive Portals and Websites

    - by kellsey.ruppel
    As more and more business is being conducted via online channels, engaging users and making them more productive and efficient though these online channels is becoming critical. These users could be customers, partners or employees and while the respective channels through which they interact might be different, these users do increasingly interact with your business through the Web, or mobile devices or now through various social mediums.  Businesses need a user engagement strategy and solution that allows them to deliver targeted and personalized content and applications to users through the various online mediums and touch points.  The customer experience today is made up of an ongoing set of interactions with organizations across many channels, online and offline.  The Direct channel (including sales reps, email and mail) is an important point of contact, as is the Contact Center.  Contact Centers rely on the phone as a means of interacting with customers, and also more now than ever, the Web as well.  However, the online organization is often managed separately from the Contact Center organization within a business. In-store is an important channel for retailers, offering Point-of-Service for human interactions, and Kiosks which enable self-service. Kiosks are a Web-enabled touch point but in-store kiosks are often managed by the head of retail operations, rather than the online organization.  And of course, the online channel, including customer interactions with an organization via digital means -- on the website, mobile websites, and social networking sites, has risen to paramount importance in recent years in the customer experience. Historically all of these channels have been managed separately. The result of all of this fragmentation is that the customer touch points with an organization are siloed.  Their interactions online are not known and respected in their dealings in-store.  Their calls to the contact center are not taken as input into what the website offers them when they arrive. Think of how many times you’ve fallen victim to this. Your experience with the company call center is different than the experience in-store. Your experience with the company website on your desktop computer is different than your experience on your iPad. I think you get the point. But the customer isn’t the only one we need to look at here, as employees and the IT organization have challenges as well when it comes to online engagement. There are many common tools and technologies that organizations have been using to try and engage users, whether it’s customers, employees or partners. Some have adopted different blog and wiki technologies (some hosted, some open source, sometimes embedded in platforms), to things like tagging, file sharing and content management, or composite applications for self-service applications and activity streams. Basically, there are so many different tools & technologies that each address different aspects of user engagement. Now, one of the challenges with this, is that if we look at each individual tool, typically just implementing for example a file sharing and basic collaboration solution, may meet the needs of the business user for one aspect of user engagement, but it may not be the best solution to engage with customers and partners, or it may not fit with IT standards such as integrating with their single sign on tools or their corporate website. Often, the scenario is that businesses are having to acquire multiple pieces and parts as well as build custom applications to meet their needs. Leaving customers and partners with a more fragmented way of interacting with the company. Every organization has some sort of enterprise balancing act between the needs of the business user and the needs and restrictions enforced by enterprise IT groups. As we’ve been discussing, we all know that the expectations for online engagement have changed since the days of the static, one-size fits all website. With these changes have come some very difficult organizational challenges as well. Today, as a business user, you want to engage with your customers, and your customers expect you to know who they are. They expect you to recall the details they’ve provided to you on your website, to your CSRs and to your sales people. They expect you to remember their purchases, their preferences and their problems. And they expect you to know who they are, equally well, across channels, including your web presence. This creates a host of challenges for today’s business users. Delivering targeted, relevant content online is now essential for converting prospects into customers and for engendering long term loyalty. Business users need the ability to leverage customer data from different sources to fuel their segmentation and targeting strategies and to easily set-up, manage and optimize online campaigns. Also critical, they need the ability to accomplish these things on-the-fly, at the speed of the marketplace, while making iterative improvements.  These changing expectations put a host of demands on the IT organization as well. The web presence must be able to scale to support the delivery of personalized and targeted content to thousands of site visitors without sacrificing performance. And integration between systems becomes more important as well, as organizations strive to obtain one view of the customer culled from WCM data, CRM data and more. So then, how do you solve these challenges and meet the growing demands of your users?  You need a solution that: Unifies every customer interaction across all channels Personalizes the products and content that interest the customer and to the device Delivers targeted promotions to the right customer Engages and improve employee productivity Provides self-service access to applications Includes embedded in-context social   So how then do you achieve this level of online engagement, complete customer experience and engage your employees? The answer: Oracle WebCenter. If you want to learn how to get there, we encourage you to attend this webcast on Thursday Drive Online Engagement with Intuitive Portals and Websites, where we'll talk about how you are able to transform your portal experience and optimize online engagement -- making your portals more interactive and more engaging across multiple channels. Register today!

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  • Microsoft BUILD 2013 Day 1&ndash;Keynote

    - by Tim Murphy
    Originally posted on: http://geekswithblogs.net/tmurphy/archive/2013/06/27/microsoft-build-2013-day-1ndashkeynote.aspx This one is going to be a little long because the keynote was jam-packed so bare with me. The keynote for the first day of BUILD 2013 was kicked off by Steve Balmer.  He made it very clear that Microsoft’s focus is on accelerating its time to market with products and product updates.  His quote was that “Rapid release” is the new norm.  He continued by showing off several new Lumias that have been buzzing around the internet for a while and announce that Sprint will now be carrying the HTC 8XT and Samsung ATIV. Balmer is known for repeating words or phrase for affect.  This time it was “Rapid release, rapid release” and “Touch, touch, touch, touch, touch, …”.  This was fun, but even more fun was when he announce that all attendees would receive an Acer Iconia 8” tablet. SCORE! The next subject Balmer focused on is new apps.  The three new ones were Flipboard, Facebook and NFL Fantasy Football.  I liked the first two because these are ones that people coming from other platforms are missing.  The NFL app is great just because it targets a demographic that can be fanatical.  If these types of apps keep coming than the missing app argument goes away. While many Negative Nancy’s are describing Windows 8.1 as Windows 180 Steve Balmer chose to call it a “refined blend” as in a coffee that has been improved with a new mix.  This includes more multi-tasking options and leveraging Bing straight throughout the entire ecosystem. He ended this first section by explaining that this will also bring more Bing development opportunities to the community. Steve Balmer was followed by Julie Larson-Green who spent her time on stage selling us on Windows 8 all over again from my point of view.  Something that I would not have thought was needed until I had listened to some other attendees who had a number of concerns and complaints.  She showed a number of new gestures that will come with Windows 8.1, and while they were cool I was left wondering if they really improved the experience.  I guess only time will tell. I did like the fact that it the UI implementation to bring up “All Apps” now mirrors that of Windows Phone.  The consistency is a big step forward that I hope to see continue.  The cool factor went up from there as she swiped content from a desktop (mega-tablet) to the XBox One.  This seamless experience I believe is what is really needed for any future platform to be relevant. I was much more enthused by the presentation of Antoine Leblond who humbled us by letting us know that there are 5k new API.  How that can be or how anyone would ever use all of them is another question.  His announcement was that the Visual Studio 2013 preview would be available today along with the Windows 8.1 bits.  One of the features of VS2013 that he demonstrated is the power consumption profiler.  With battery life being a key factor with consumer consumption devices this is a welcome addition. He didn’t limit his presentation to VS2013 features though.  He showed how the Store has been redesigned to enable better search and discoverability of apps and how Win 8.1 can perform multiple screen scales depending on the resolution of the device automatically.  The last feature he demoed was the real time video streaming API which he made sure we understood by attaching a Surface to a little robot.  Oh, but there was one more thing.  Antoine and Julie announce that all attendees would also be getting Surface Pros.  BONUS! How much more could there be?  Gurdeep Singh Pall was about to pile on.  He introduced us to Bing as a platform (BaaP?).  He said if they (Microsoft) could do something with and API that is good 3rd party developers can do something that is dynamite and showed us some of the tools they had produced.  These included natural user interface improvements such as voice commands that looked to put Siri to shame.  Add to that 3D, OCR and translation capabilities and the future looks to be full of opportunities. Balmer then came out to show us one last thing.  Project Spark is a game design environment that will be available for Windows 8.1, XBox 360 and XBox One.  All I can say is that if my kids get their hands on this they are going to be able to learn some of what dad does in a much more enjoyable way. At the end of it all I was both exhausted and energized by what I saw.  What could they have possibly left for the day 2 keynote?  I hear it will feature Scott Hanselman.  If that is right we are in for a treat.  See you there. del.icio.us Tags: BUILD 2013,Windows 8.1,Winodws Phone,XAML,Keynote,Bing,Visual Studio 2013,Project Spark

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  • What Can We Learn About Software Security by Going to the Gym

    - by Nick Harrison
    There was a recent rash of car break-ins at the gym. Not an epidemic by any stretch, probably 4 or 5, but still... My gym used to allow you to hang your keys from a peg board at the front desk. This way you could come to the gym dressed to work out, lock your valuables in your car, and not have anything to worry about. Ignorance is bliss. The problem was that anyone who wanted to could go pick up your car keys, click the unlock button and find your car. Once there, they could rummage through your stuff and then walk back in and finish their workout as if nothing had happened. The people doing this were a little smatter then the average thief and would swipe some but not all of your cash leaving everything else in place. Most thieves would steal the whole car and be busted more quickly. The victims were unaware that anything had happened for several days. Fortunately, once the victims realized what had happened, the gym was still able to pull security tapes and find out who was misbehaving. All of the bad guys were busted, and everyone can now breathe a sigh of relieve. It is once again safe to go to the gym. Except there was still a fundamental problem. Putting your keys on a peg board by the front door is just asking for bad things to happen. One person got busted exploiting this security flaw. Others can still be exploiting it. In fact, others may well have been exploiting it and simply never got caught. How long would it take you to realize that $10 was missing from your wallet, if everything else was there? How would you even know when it went missing? Would you go to the front desk and even bother to ask them to review security tapes if you were only missing a small amount. Once highlighted, it is easy to see how commonly such vulnerability may have been exploited. So the gym did the very reasonable precaution of removing the peg board. To me the most shocking part of this story is the resulting uproar from gym members losing the convenient key peg. How dare they remove the trusted peg board? How can I work out now, I have to carry my keys from machine to machine? How can I enjoy my workout with this added inconvenience? This all happened a couple of weeks ago, and some people are still complaining. In light of the recent high profile hacking, there are a couple of parallels that can be drawn. Many web sites are riddled with vulnerabilities are crazy and easily exploitable as leaving your car keys by the front door while you work out. No one ever considered thanking the people who were swiping these keys for pointing out the vulnerability. Without a hesitation, they had their gym memberships revoked and are awaiting prosecution. The gym did recognize the vulnerability for what it is, and closed up that attack vector. What can we learn from this? Monitoring and logging will not prevent a crime but they will allow us to identify that a crime took place and may help track down who did it. Once we find a security weakness, we need to eliminate it. We may never identify and eliminate all security weaknesses, but we cannot allow well known vulnerabilities to persist in our system. In our case, we are not likely to meet resistance from end users. We are more likely to meet resistance from stake holders, product owners, keeper of schedules and budgets. We may meet resistance from integration partners, co workers, and third party vendors. Regardless of the source, we will see resistance, but the weakness needs to be dealt with. There is no need to glorify a cracker for bringing to light a security weakness. Regardless of their claimed motives, they are not heroes. There is also no point in wasting time defending weaknesses once they are identified. Deal with the weakness and move on. In may be embarrassing to find security weaknesses in our systems, but it is even more embarrassing to continue ignoring them. Even if it is unpopular, we need to seek out security weaknesses and eliminate them when we find them. http://www.sans.org has put together the Common Weakness Enumeration http://cwe.mitre.org/ which lists out common weaknesses. The site navigation takes a little getting used to, but there is a treasure trove here. Here is the detail page for SQL Injection. It clearly states how this can be exploited, in case anyone doubts that the weakness should be taken seriously, and more importantly how to mitigate the risk.

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  • Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

    - by GABMARTINEZ
    Entity Framework 4.3.1 includes a new feature called code first migrations.  We are adding support for this feature in our upcoming 6.6 release of Connector/Net.  In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database.   The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager.  You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application  Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a  <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations;     //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext>  //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());     }   }  This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations.  Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version         Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes.  It will execute the Up method in the initial migration which has no changes in the database. And second, and very important,  it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community.  Happy MySQL/Net Coding!

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  • Windows in StreamInsight: Hopping vs. Snapshot

    - by Roman Schindlauer
    Three weeks ago, we explained the basic concept of windows in StreamInsight: defining sets of events that serve as arguments for set-based operations, like aggregations. Today, we want to discuss the so-called Hopping Windows and compare them with Snapshot Windows. We will compare these two, because they can serve similar purposes with different behaviors; we will discuss the remaining window type, Count Windows, another time. Hopping (and its syntactic-sugar-sister Tumbling) windows are probably the most straightforward windowing concept in StreamInsight. A hopping window is defined by its length, and the offset from one window to the next. They are aligned with some absolute point on the timeline (which can also be given as a parameter to the window) and create sets of events. The diagram below shows an example of a hopping window with length of 1h and hop size (the offset) of 15 minutes, hence creating overlapping windows:   Two aspects in this diagram are important: Since this window is overlapping, an event can fall into more than one windows. If an (interval) event spans a window boundary, its lifetime will be clipped to the window, before it is passed to the set-based operation. That’s the default and currently only available window input policy. (This should only concern you if you are using a time-sensitive user-defined aggregate or operator.) The set-based operation will be applied to each of these sets, yielding a result. This result is: A single scalar value in case of built-in or user-defined aggregates. A subset of the input payloads, in case of the TopK operator. Arbitrary events, when using a user-defined operator. The timestamps of the result are almost always the ones of the windows. Only the user-defined  operator can create new events with timestamps. (However, even these event lifetimes are subject to the window’s output policy, which is currently always to clip to the window end.) Let’s assume we were calculating the sum over some payload field: var result = from window in source.HoppingWindow( TimeSpan.FromHours(1), TimeSpan.FromMinutes(15), HoppingWindowOutputPolicy.ClipToWindowEnd) select new { avg = window.Avg(e => e.Value) }; Now each window is reflected by one result event:   As you can see, the window definition defines the output frequency. No matter how many or few events we got from the input, this hopping window will produce one result every 15 minutes – except for those windows that do not contain any events at all, because StreamInsight window operations are empty-preserving (more about that another time). The “forced” output for every window can become a performance issue if you have a real-time query with many events in a wide group & apply – let me explain: imagine you have a lot of events that you group by and then aggregate within each group – classical streaming pattern. The hopping window produces a result in each group at exactly the same point in time for all groups, since the window boundaries are aligned with the timeline, not with the event timestamps. This means that the query output will become very bursty, delivering the results of all the groups at the same point in time. This becomes especially obvious if the events are long-lasting, spanning multiple windows each, so that the produced result events do not change their value very often. In such a case, a snapshot window can remedy. Snapshot windows are more difficult to explain than hopping windows: they represent those periods in time, when no event changes occur. In other words, if you mark all event start and and times on your timeline, then you are looking at all snapshot window boundaries:   If your events are never overlapping, the snapshot window will not make much sense. It is commonly used together with timestamp modification, which make it a very powerful tool. Or as Allan Mitchell expressed in in a recent tweet: “I used to look at SnapshotWindow() with disdain. Now she is my mistress, the one I turn to in times of trouble and need”. Let’s look at a simple example: I want to compute the average of some value in my events over the last minute. I don’t want this output be produced at fixed intervals, but at soon as it changes (that’s the true event-driven spirit!). The snapshot window will include all currently active event at each point in time, hence we need to extend our original events’ lifetimes into the future: Applying the Snapshot window on these events, it will appear to be “looking back into the past”: If you look at the result produced in this diagram, you can easily prove that, at each point in time, the current event value represents the average of all original input event within the last minute. Here is the LINQ representation of that query, applying the lifetime extension before the snapshot window: var result = from window in source .AlterEventDuration(e => TimeSpan.FromMinutes(1)) .SnapshotWindow(SnapshotWindowOutputPolicy.Clip) select new { avg = window.Avg(e => e.Value) }; With more complex modifications of the event lifetimes you can achieve many more query patterns. For instance “running totals” by keeping the event start times, but snapping their end times to some fixed time, like the end of the day. Each snapshot then “sees” all events that have happened in the respective time period so far. Regards, The StreamInsight Team

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  • CPU Usage in Very Large Coherence Clusters

    - by jpurdy
    When sizing Coherence installations, one of the complicating factors is that these installations (by their very nature) tend to be application-specific, with some being large, memory-intensive caches, with others acting as I/O-intensive transaction-processing platforms, and still others performing CPU-intensive calculations across the data grid. Regardless of the primary resource requirements, Coherence sizing calculations are inherently empirical, in that there are so many permutations that a simple spreadsheet approach to sizing is rarely optimal (though it can provide a good starting estimate). So we typically recommend measuring actual resource usage (primarily CPU cycles, network bandwidth and memory) at a given load, and then extrapolating from those measurements. Of course there may be multiple types of load, and these may have varying degrees of correlation -- for example, an increased request rate may drive up the number of objects "pinned" in memory at any point, but the increase may be less than linear if those objects are naturally shared by concurrent requests. But for most reasonably-designed applications, a linear resource model will be reasonably accurate for most levels of scale. However, at extreme scale, sizing becomes a bit more complicated as certain cluster management operations -- while very infrequent -- become increasingly critical. This is because certain operations do not naturally tend to scale out. In a small cluster, sizing is primarily driven by the request rate, required cache size, or other application-driven metrics. In larger clusters (e.g. those with hundreds of cluster members), certain infrastructure tasks become intensive, in particular those related to members joining and leaving the cluster, such as introducing new cluster members to the rest of the cluster, or publishing the location of partitions during rebalancing. These tasks have a strong tendency to require all updates to be routed via a single member for the sake of cluster stability and data integrity. Fortunately that member is dynamically assigned in Coherence, so it is not a single point of failure, but it may still become a single point of bottleneck (until the cluster finishes its reconfiguration, at which point this member will have a similar load to the rest of the members). The most common cause of scaling issues in large clusters is disabling multicast (by configuring well-known addresses, aka WKA). This obviously impacts network usage, but it also has a large impact on CPU usage, primarily since the senior member must directly communicate certain messages with every other cluster member, and this communication requires significant CPU time. In particular, the need to notify the rest of the cluster about membership changes and corresponding partition reassignments adds stress to the senior member. Given that portions of the network stack may tend to be single-threaded (both in Coherence and the underlying OS), this may be even more problematic on servers with poor single-threaded performance. As a result of this, some extremely large clusters may be configured with a smaller number of partitions than ideal. This results in the size of each partition being increased. When a cache server fails, the other servers will use their fractional backups to recover the state of that server (and take over responsibility for their backed-up portion of that state). The finest granularity of this recovery is a single partition, and the single service thread can not accept new requests during this recovery. Ordinarily, recovery is practically instantaneous (it is roughly equivalent to the time required to iterate over a set of backup backing map entries and move them to the primary backing map in the same JVM). But certain factors can increase this duration drastically (to several seconds): large partitions, sufficiently slow single-threaded CPU performance, many or expensive indexes to rebuild, etc. The solution of course is to mitigate each of those factors but in many cases this may be challenging. Larger clusters also lead to the temptation to place more load on the available hardware resources, spreading CPU resources thin. As an example, while we've long been aware of how garbage collection can cause significant pauses, it usually isn't viewed as a major consumer of CPU (in terms of overall system throughput). Typically, the use of a concurrent collector allows greater responsiveness by minimizing pause times, at the cost of reducing system throughput. However, at a recent engagement, we were forced to turn off the concurrent collector and use a traditional parallel "stop the world" collector to reduce CPU usage to an acceptable level. In summary, there are some less obvious factors that may result in excessive CPU consumption in a larger cluster, so it is even more critical to test at full scale, even though allocating sufficient hardware may often be much more difficult for these large clusters.

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  • Null Values And The T-SQL IN Operator

    - by Jesse
    I came across some unexpected behavior while troubleshooting a failing test the other day that took me long enough to figure out that I thought it was worth sharing here. I finally traced the failing test back to a SELECT statement in a stored procedure that was using the IN t-sql operator to exclude a certain set of values. Here’s a very simple example table to illustrate the issue: Customers CustomerId INT, NOT NULL, Primary Key CustomerName nvarchar(100) NOT NULL SalesRegionId INT NULL   The ‘SalesRegionId’ column contains a number representing the sales region that the customer belongs to. This column is nullable because new customers get created all the time but assigning them to sales regions is a process that is handled by a regional manager on a periodic basis. For the purposes of this example, the Customers table currently has the following rows: CustomerId CustomerName SalesRegionId 1 Customer A 1 2 Customer B NULL 3 Customer C 4 4 Customer D 2 5 Customer E 3   How could we write a query against this table for all customers that are NOT in sales regions 2 or 4? You might try something like this: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE SalesRegionId NOT IN (2,4)   Will this work? In short, no; at least not in the way that you might expect. Here’s what this query will return given the example data we’re working with: CustomerId CustomerName SalesRegionId 1 Customer A 1 5 Customer E 5   I was expecting that this query would also return ‘Customer B’, since that customer has a NULL SalesRegionId. In my mind, having a customer with no sales region should be included in a set of customers that are not in sales regions 2 or 4.When I first started troubleshooting my issue I made note of the fact that this query should probably be re-written without the NOT IN clause, but I didn’t suspect that the NOT IN clause was actually the source of the issue. This particular query was only one minor piece in a much larger process that was being exercised via an automated integration test and I simply made a poor assumption that the NOT IN would work the way that I thought it should. So why doesn’t this work the way that I thought it should? From the MSDN documentation on the t-sql IN operator: If the value of test_expression is equal to any value returned by subquery or is equal to any expression from the comma-separated list, the result value is TRUE; otherwise, the result value is FALSE. Using NOT IN negates the subquery value or expression. The key phrase out of that quote is, “… is equal to any expression from the comma-separated list…”. The NULL SalesRegionId isn’t included in the NOT IN because of how NULL values are handled in equality comparisons. From the MSDN documentation on ANSI_NULLS: The SQL-92 standard requires that an equals (=) or not equal to (<>) comparison against a null value evaluates to FALSE. When SET ANSI_NULLS is ON, a SELECT statement using WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement using WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name. In fact, the MSDN documentation on the IN operator includes the following blurb about using NULL values in IN sub-queries or expressions that are used with the IN operator: Any null values returned by subquery or expression that are compared to test_expression using IN or NOT IN return UNKNOWN. Using null values in together with IN or NOT IN can produce unexpected results. If I were to include a ‘SET ANSI_NULLS OFF’ command right above my SELECT statement I would get ‘Customer B’ returned in the results, but that’s definitely not the right way to deal with this. We could re-write the query to explicitly include the NULL value in the WHERE clause: 1: SELECT 2: CustomerId, 3: CustomerName, 4: SalesRegionId 5: FROM Customers 6: WHERE (SalesRegionId NOT IN (2,4) OR SalesRegionId IS NULL)   This query works and properly includes ‘Customer B’ in the results, but I ultimately opted to re-write the query using a LEFT OUTER JOIN against a table variable containing all of the values that I wanted to exclude because, in my case, there could potentially be several hundred values to be excluded. If we were to apply the same refactoring to our simple sales region example we’d end up with: 1: DECLARE @regionsToIgnore TABLE (IgnoredRegionId INT) 2: INSERT @regionsToIgnore values (2),(4) 3:  4: SELECT 5: c.CustomerId, 6: c.CustomerName, 7: c.SalesRegionId 8: FROM Customers c 9: LEFT OUTER JOIN @regionsToIgnore r ON r.IgnoredRegionId = c.SalesRegionId 10: WHERE r.IgnoredRegionId IS NULL By performing a LEFT OUTER JOIN from Customers to the @regionsToIgnore table variable we can simply exclude any rows where the IgnoredRegionId is null, as those represent customers that DO NOT appear in the ignored regions list. This approach will likely perform better if the number of sales regions to ignore gets very large and it also will correctly include any customers that do not yet have a sales region.

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  • Oracle NoSQL Database Exceeds 1 Million Mixed YCSB Ops/Sec

    - by Charles Lamb
    We ran a set of YCSB performance tests on Oracle NoSQL Database using SSD cards and Intel Xeon E5-2690 CPUs with the goal of achieving 1M mixed ops/sec on a 95% read / 5% update workload. We used the standard YCSB parameters: 13 byte keys and 1KB data size (1,102 bytes after serialization). The maximum database size was 2 billion records, or approximately 2 TB of data. We sized the shards to ensure that this was not an "in-memory" test (i.e. the data portion of the B-Trees did not fit into memory). All updates were durable and used the "simple majority" replica ack policy, effectively 'committing to the network'. All read operations used the Consistency.NONE_REQUIRED parameter allowing reads to be performed on any replica. In the past we have achieved 100K ops/sec using SSD cards on a single shard cluster (replication factor 3) so for this test we used 10 shards on 15 Storage Nodes with each SN carrying 2 Rep Nodes and each RN assigned to its own SSD card. After correcting a scaling problem in YCSB, we blew past the 1M ops/sec mark with 8 shards and proceeded to hit 1.2M ops/sec with 10 shards.  Hardware Configuration We used 15 servers, each configured with two 335 GB SSD cards. We did not have homogeneous CPUs across all 15 servers available to us so 12 of the 15 were Xeon E5-2690, 2.9 GHz, 2 sockets, 32 threads, 193 GB RAM, and the other 3 were Xeon E5-2680, 2.7 GHz, 2 sockets, 32 threads, 193 GB RAM.  There might have been some upside in having all 15 machines configured with the faster CPU, but since CPU was not the limiting factor we don't believe the improvement would be significant. The client machines were Xeon X5670, 2.93 GHz, 2 sockets, 24 threads, 96 GB RAM. Although the clients had 96 GB of RAM, neither the NoSQL Database or YCSB clients require anywhere near that amount of memory and the test could have just easily been run with much less. Networking was all 10GigE. YCSB Scaling Problem We made three modifications to the YCSB benchmark. The first was to allow the test to accommodate more than 2 billion records (effectively int's vs long's). To keep the key size constant, we changed the code to use base 32 for the user ids. The second change involved to the way we run the YCSB client in order to make the test itself horizontally scalable.The basic problem has to do with the way the YCSB test creates its Zipfian distribution of keys which is intended to model "real" loads by generating clusters of key collisions. Unfortunately, the percentage of collisions on the most contentious keys remains the same even as the number of keys in the database increases. As we scale up the load, the number of collisions on those keys increases as well, eventually exceeding the capacity of the single server used for a given key.This is not a workload that is realistic or amenable to horizontal scaling. YCSB does provide alternate key distribution algorithms so this is not a shortcoming of YCSB in general. We decided that a better model would be for the key collisions to be limited to a given YCSB client process. That way, as additional YCSB client processes (i.e. additional load) are added, they each maintain the same number of collisions they encounter themselves, but do not increase the number of collisions on a single key in the entire store. We added client processes proportionally to the number of records in the database (and therefore the number of shards). This change to the use of YCSB better models a use case where new groups of users are likely to access either just their own entries, or entries within their own subgroups, rather than all users showing the same interest in a single global collection of keys. If an application finds every user having the same likelihood of wanting to modify a single global key, that application has no real hope of getting horizontal scaling. Finally, we used read/modify/write (also known as "Compare And Set") style updates during the mixed phase. This uses versioned operations to make sure that no updates are lost. This mode of operation provides better application behavior than the way we have typically run YCSB in the past, and is only practical at scale because we eliminated the shared key collision hotspots.It is also a more realistic testing scenario. To reiterate, all updates used a simple majority replica ack policy making them durable. Scalability Results In the table below, the "KVS Size" column is the number of records with the number of shards and the replication factor. Hence, the first row indicates 400m total records in the NoSQL Database (KV Store), 2 shards, and a replication factor of 3. The "Clients" column indicates the number of YCSB client processes. "Threads" is the number of threads per process with the total number of threads. Hence, 90 threads per YCSB process for a total of 360 threads. The client processes were distributed across 10 client machines. Shards KVS Size Clients Mixed (records) Threads OverallThroughput(ops/sec) Read Latencyav/95%/99%(ms) Write Latencyav/95%/99%(ms) 2 400m(2x3) 4 90(360) 302,152 0.76/1/3 3.08/8/35 4 800m(4x3) 8 90(720) 558,569 0.79/1/4 3.82/16/45 8 1600m(8x3) 16 90(1440) 1,028,868 0.85/2/5 4.29/21/51 10 2000m(10x3) 20 90(1800) 1,244,550 0.88/2/6 4.47/23/53

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  • A Knights Tale

    - by Phil Factor
    There are so many lessons to be learned from the story of Knight Capital losing nearly half a billion dollars as a result of a deployment gone wrong. The Knight Capital Group (KCG N) was an American global financial services firm engaging in market making, electronic execution, and institutional sales and trading. According to the recent order (File No.3.15570) against Knight Capital by U.S. Securities and Exchange Commission?, Knight had, for many years used some software which broke up incoming “parent” orders into smaller “child” orders that were then transmitted to various exchanges or trading venues for execution. A tracking ‘cumulative quantity’ function counted the number of ‘child’ orders and stopped the process once the total of child orders matched the ‘parent’ and so the parent order had been completed. Back in the mists of time, some code had been added to it  which was excuted if a particular flag was set. It was called ‘power peg’ and seems to have had a similar design and purpose, but, one guesses, would have shared the same tracking function. This code had been abandoned in 2003, but never deleted. In 2005, The tracking function was moved to an earlier point in the main process. It would seem from the account that, from that point, had that flag ever been set, the old ‘Power Peg’ would have been executed like Godzilla bursting from the ice, making child orders without limit without any tracking function. It wasn’t, presumably because the software that set the flag was removed. In 2012, nearly a decade after ‘Power Peg’ was abandoned, Knight prepared a new module to their software to cope with the imminent Retail Liquidity Program (RLP) for the New York Stock Exchange. By this time, the flag had remained unused and someone made the fateful decision to reuse it, and replace the old ‘power peg’ code with this new RLP code. Had the two actions been done together in a single automated deployment, and the new deployment tested, all would have been well. It wasn’t. To quote… “Beginning on July 27, 2012, Knight deployed the new RLP code in SMARS in stages by placing it on a limited number of servers in SMARS on successive days. During the deployment of the new code, however, one of Knight’s technicians did not copy the new code to one of the eight SMARS computer servers. Knight did not have a second technician review this deployment and no one at Knight realized that the Power Peg code had not been removed from the eighth server, nor the new RLP code added. Knight had no written procedures that required such a review.” (para 15) “On August 1, Knight received orders from broker-dealers whose customers were eligible to participate in the RLP. The seven servers that received the new code processed these orders correctly. However, orders sent with the repurposed flag to the eighth server triggered the defective Power Peg code still present on that server. As a result, this server began sending child orders to certain trading centers for execution. Because the cumulative quantity function had been moved, this server continuously sent child orders, in rapid sequence, for each incoming parent order without regard to the number of share executions Knight had already received from trading centers. Although one part of Knight’s order handling system recognized that the parent orders had been filled, this information was not communicated to SMARS.” (para 16) SMARS routed millions of orders into the market over a 45-minute period, and obtained over 4 million executions in 154 stocks for more than 397 million shares. By the time that Knight stopped sending the orders, Knight had assumed a net long position in 80 stocks of approximately $3.5 billion and a net short position in 74 stocks of approximately $3.15 billion. Knight’s shares dropped more than 20% after traders saw extreme volume spikes in a number of stocks, including preferred shares of Wells Fargo (JWF) and semiconductor company Spansion (CODE). Both stocks, which see roughly 100,000 trade per day, had changed hands more than 4 million times by late morning. Ultimately, Knight lost over $460 million from this wild 45 minutes of trading. Obviously, I’m interested in all this because, at one time, I used to write trading systems for the City of London. Obviously, the US SEC is in a far better position than any of us to work out the failings of Knight’s IT department, and the report makes for painful reading. I can’t help observing, though, that even with the breathtaking mistakes all along the way, that a robust automated deployment process that was ‘all-or-nothing’, and tested from soup to nuts would have prevented the disaster. The report reads like a Greek Tragedy. All the way along one wants to shout ‘No! not that way!’ and ‘Aargh! Don’t do it!’. As the tragedy unfolds, the audience weeps for the players, trapped by a cruel fate. All application development and deployment requires defense in depth. All IT goes wrong occasionally, but if there is a culture of defensive programming throughout, the consequences are usually containable. For financial systems, these defenses are required by statute, and ignored only by the foolish. Knight’s mistakes weren’t made by just one hapless sysadmin, but were progressive errors by an  IT culture spanning at least ten years.  One can spell these out, but I think they’re obvious. One can only hope that the industry studies what happened in detail, learns from the mistakes, and draws the right conclusions.

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  • On Reflector Pricing

    - by Nick Harrison
    I have heard a lot of outrage over Red Gate's decision to charge for Reflector. In the interest of full disclosure, I am a fan of Red Gate. I have worked with them on several usability tests. They also sponsor Simple Talk where I publish articles. They are a good company. I am also a BIG fan of Reflector. I have used it since Lutz originally released it. I have written my own add-ins. I have written code to host reflector and use its object model in my own code. Reflector is a beautiful tool. The care that Lutz took to incorporate extensibility is amazing. I have never had difficulty convincing my fellow developers that it is a wonderful tool. Almost always, once anyone sees it in action, it becomes their favorite tool. This wide spread adoption and usability has made it an icon and pivotal pillar in the DotNet community. Even folks with the attitude that if it did not come out of Redmond then it must not be any good, still love it. It is ironic to hear everyone clamoring for it to be released as open source. Reflector was never open source, it was free, but you never were able to peruse the source code and contribute your own changes. You could not even use Reflector to view the source code. From the very beginning, it was never anyone's intention for just anyone to examine the source code and make their own contributions aside from the add-in model. Lutz chose to hand over the reins to Red Gate because he believed that they would be able to build on his original vision and keep the product viable and effective. He did not choose to make it open source, hoping that the community would be up to the challenge. The simplicity and elegance may well have been lost with the "design by committee" nature of open source. Despite being a wonderful and beloved tool, Reflector cannot be an easy tool to maintain. Maybe because it is so wonderful and beloved, it is even more difficult to maintain. At any rate, we have high expectations. Reflector must continue to be able to reasonably disassemble every language construct that the framework and core languages dream up. We want it to be fast, and we also want it to continue to be simple to use. No small order. Red Gate tried to keep the core product free. Sadly there was not enough interest in the Pro version to subsidize the rest of the expenses. $35 is a reasonable cost, more than reasonable. I have read the blog posts and forum posts complaining about the time associated with getting the expense approved. I have heard people complain about the cost being unreasonable if you are a developer from certain countries. Let's do the math. How much of a productivity boost is Reflector? How many hours do you think it saves you in a typical project? The next question is a little easier if you are a contractor or a consultant, but what is your hourly rate? If you are not a contractor, you can probably figure out an hourly rate. How long does it take to get a return on your investment? The value added proposition is not a difficult one to make. I have read people clamoring that Red Gate sucks and is evil. They complain about broken promises and conflicts of interest. Relax! Red Gate is not evil. The world is not coming to an end. The sun will come up tomorrow. I am sure that Red Gate will come up with options for volume licensing or site licensing for companies that want to get a licensed copy for their entire team. Don't panic, and I am sure that many great improvements are on the horizon. Switching the UI to WPF and including a tabbed interface opens up lots of possibilities.

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