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  • What's My Problem? What's Your Problem?

    - by Jacek Ziabicki
    Software installers are not made for building demo environments. I can say this much after 12 years (on and off) of supporting my fellow sales consultants with environments for software demonstrations. When we release software, we include installation programs and procedures that are designed for use by our clients – to build a production environment and a limited number of testing, training and development environments. Different Objectives Your priorities when building an environment for client use vs. building a demo environment are very different. In a production environment, security, stability, and performance concerns are paramount. These environments are built on a specific server and rarely, if ever, moved to a different server or different network address. There is typically just one application running on a particular server (physical or virtual). Once built, the environment will be used for months or years at a time. Because of security considerations, the installation program wants to make these environments very specific to the organization using the software and the use case, encoding a fully qualified name of the server, or even the IP address on the network, in the configuration. So you either go through the installation procedure for each environment, or learn how to clone and reconfigure the software as a separate instance to build all your non-production environments. This may not matter much if the installation is as simple as clicking on the Setup program. But for enterprise applications, you have a number of configuration settings that you need to get just right – so whether you are installing from scratch or reconfiguring an existing installation, this requires both time and expertise in the particular piece of software. If you need a setup of several applications that are integrated to talk to one another, it is a whole new level of complexity. Now you need the expertise in all of the applications involved (plus the supporting technology products), and in addition to making each application work, you also have to configure the integration endpoints. Each application needs the URLs and credentials to call the integration layer, and the integration must be able to call each application. Then you have to make sure that each app has the right data so a business process initiated in one application can continue in the next. And, you will need to check that each application has the correct version and patch level for the integration to work. When building demo environments, your #1 concern is agility. If you can get away with a small number of long-running environments, you are lucky. More likely, you may get a request for a dedicated environment for a demonstration that is two weeks away: how quickly can you make this available so we still have the time to build the client-specific data? We are running a hands-on workshop next month, and we’ll need 15 instances of application X environment so each student can have a separate server for the exercises. We cannot connect to our data center from the client site, the client’s security policy won’t allow our VPN to go through – so we need a portable environment that we can bring with us. Our consultants need to be able to work at the hotel, airport, and the airplane, so we really want an environment that can run on a laptop. The client will need two playpen environments running in the cloud, accessible from their network, for a series of workshops that start two weeks from now. We have seen all of these scenarios and more. Here you would be much better served by a generic installation that would be easy to clone. Welcome to the Wonder Machine The reason I started this blog is to share a particular design of a demo environment, a special way to install software, that can address the above requirements, even for integrated setups. This design was created by a team at Oracle Utilities Global Business Unit, and we are using this setup for most of our demo environments. In a bout of modesty we called it the Wonder Machine. Over the next few posts – think of it as a novel in parts – I will tell you about the big idea, how it was implemented and what you can do with it. After we have laid down the groundwork, I would like to share some tips and tricks for users of our Wonder Machine implementation, as well as things I am learning about building portable, cloneable environments. The Wonder Machine is by no means a closed specification, it is under active development! I am hoping this blog will be of interest to two groups of readers – the users of the Wonder Machine we have built at Oracle Utilities, who want to get the most out of their demo environments and be able to reconfigure it to their needs – and to people who need to build environments for demonstration, testing, training, development and would like to make them cloneable and portable to maximize the reuse of their effort. Surely we are not the only ones facing this problem? If you can think of a better way to solve it, or if you can help us improve on our concept, I will appreciate your comments!

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  • High Availability for IaaS, PaaS and SaaS in the Cloud

    - by BuckWoody
    Outages, natural disasters and unforeseen events have proved that even in a distributed architecture, you need to plan for High Availability (HA). In this entry I'll explain a few considerations for HA within Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). In a separate post I'll talk more about Disaster Recovery (DR), since each paradigm has a different way to handle that. Planning for HA in IaaS IaaS involves Virtual Machines - so in effect, an HA strategy here takes on many of the same characteristics as it would on-premises. The primary difference is that the vendor controls the hardware, so you need to verify what they do for things like local redundancy and so on from the hardware perspective. As far as what you can control and plan for, the primary factors fall into three areas: multiple instances, geographical dispersion and task-switching. In almost every cloud vendor I've studied, to ensure your application will be protected by any level of HA, you need to have at least two of the Instances (VM's) running. This makes sense, but you might assume that the vendor just takes care of that for you - they don't. If a single VM goes down (for whatever reason) then the access to it is lost. Depending on multiple factors, you might be able to recover the data, but you should assume that you can't. You should keep a sync to another location (perhaps the vendor's storage system in another geographic datacenter or to a local location) to ensure you can continue to serve your clients. You'll also need to host the same VM's in another geographical location. Everything from a vendor outage to a network path problem could prevent your users from reaching the system, so you need to have multiple locations to handle this. This means that you'll have to figure out how to manage state between the geo's. If the system goes down in the middle of a transaction, you need to figure out what part of the process the system was in, and then re-create or transfer that state to the second set of systems. If you didn't write the software yourself, this is non-trivial. You'll also need a manual or automatic process to detect the failure and re-route the traffic to your secondary location. You could flip a DNS entry (if your application can tolerate that) or invoke another process to alias the first system to the second, such as load-balancing and so on. There are many options, but all of them involve coding the state into the application layer. If you've simply moved a state-ful application to VM's, you may not be able to easily implement an HA solution. Planning for HA in PaaS Implementing HA in PaaS is a bit simpler, since it's built on the concept of stateless applications deployment. Once again, you need at least two copies of each element in the solution (web roles, worker roles, etc.) to remain available in a single datacenter. Also, you need to deploy the application again in a separate geo, but the advantage here is that you could work out a "shared storage" model such that state is auto-balanced across the world. In fact, you don't have to maintain a "DR" site, the alternate location can be live and serving clients, and only take on extra load if the other site is not available. In Windows Azure, you can use the Traffic Manager service top route the requests as a type of auto balancer. Even with these benefits, I recommend a second backup of storage in another geographic location. Storage is inexpensive; and that second copy can be used for not only HA but DR. Planning for HA in SaaS In Software-as-a-Service (such as Office 365, or Hadoop in Windows Azure) You have far less control over the HA solution, although you still maintain the responsibility to ensure you have it. Since each SaaS is different, check with the vendor on the solution for HA - and make sure you understand what they do and what you are responsible for. They may have no HA for that solution, or pin it to a particular geo, or perhaps they have a massive HA built in with automatic load balancing (which is often the case).   All of these options (with the exception of SaaS) involve higher costs for the design. Do not sacrifice reliability for cost - that will always cost you more in the end. Build in the redundancy and HA at the very outset of the project - if you try to tack it on later in the process the business will push back and potentially not implement HA. References: http://www.bing.com/search?q=windows+azure+High+Availability  (each type of implementation is different, so I'm routing you to a search on the topic - look for the "Patterns and Practices" results for the area in Azure you're interested in)

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  • Documentation Changes in Solaris 11.1

    - by alanc
    One of the first places you can see Solaris 11.1 changes are in the docs, which have now been posted in the Solaris 11.1 Library on docs.oracle.com. I spent a good deal of time reviewing documentation for this release, and thought some would be interesting to blog about, but didn't review all the changes (not by a long shot), and am not going to cover all the changes here, so there's plenty left for you to discover on your own. Just comparing the Solaris 11.1 Library list of docs against the Solaris 11 list will show a lot of reorganization and refactoring of the doc set, especially in the system administration guides. Hopefully the new break down will make it easier to get straight to the sections you need when a task is at hand. Packaging System Unfortunately, the excellent in-depth guide for how to build packages for the new Image Packaging System (IPS) in Solaris 11 wasn't done in time to make the initial Solaris 11 doc set. An interim version was published shortly after release, in PDF form on the OTN IPS page. For Solaris 11.1 it was included in the doc set, as Packaging and Delivering Software With the Image Packaging System in Oracle Solaris 11.1, so should be easier to find, and easier to share links to specific pages the HTML version. Beyond just how to build a package, it includes details on how Solaris is packaged, and how package updates work, which may be useful to all system administrators who deal with Solaris 11 upgrades & installations. The Adding and Updating Oracle Solaris 11.1 Software Packages was also extended, including new sections on Relaxing Version Constraints Specified by Incorporations and Locking Packages to a Specified Version that may be of interest to those who want to keep the Solaris 11 versions of certain packages when they upgrade, such as the couple of packages that had functionality removed by an (unusual for an update release) End of Feature process in the 11.1 release. Also added in this release is a document containing the lists of all the packages in each of the major package groups in Solaris 11.1 (solaris-desktop, solaris-large-server, and solaris-small-server). While you can simply get the contents of those groups from the package repository, either via the web interface or the pkg command line, the documentation puts them in handy tables for easier side-by-side comparison, or viewing the lists before you've installed the system to pick which one you want to initially install. X Window System We've not had good X11 coverage in the online Solaris docs in a while, mostly relying on the man pages, and upstream X.Org docs. In this release, we've integrated some X coverage into the Solaris 11.1 Desktop Adminstrator's Guide, including sections on installing fonts for fontconfig or legacy X11 clients, X server configuration, and setting up remote access via X11 or VNC. Of course we continue to work on improving the docs, including a lot of contributions to the upstream docs all OS'es share (more about that another time). Security One of the things Oracle likes to do for its products is to publish security guides for administrators & developers to know how to build systems that meet their security needs. For Solaris, we started this with Solaris 11, providing a guide for sysadmins to find where the security relevant configuration options were documented. The Solaris 11.1 Security Guidelines extend this to cover new security features, such as Address Space Layout Randomization (ASLR) and Read-Only Zones, as well as adding additional guidelines for existing features, such as how to limit the size of tmpfs filesystems, to avoid users driving the system into swap thrashing situations. For developers, the corresponding document is the Developer's Guide to Oracle Solaris 11 Security, which has been the source for years for documentation of security-relevant Solaris API's such as PAM, GSS-API, and the Solaris Cryptographic Framework. For Solaris 11.1, a new appendix was added to start providing Secure Coding Guidelines for Developers, leveraging the CERT Secure Coding Standards and OWASP guidelines to provide the base recommendations for common programming languages and their standard API's. Solaris specific secure programming guidance was added via links to other documentation in the product doc set. In parallel, we updated the Solaris C Libary Functions security considerations list with details of Solaris 11 enhancements such as FD_CLOEXEC flags, additional *at() functions, and new stdio functions such as asprintf() and getline(). A number of code examples throughout the Solaris 11.1 doc set were updated to follow these recommendations, changing unbounded strcpy() calls to strlcpy(), sprintf() to snprintf(), etc. so that developers following our examples start out with safer code. The Writing Device Drivers guide even had the appendix updated to list which of these utility functions, like snprintf() and strlcpy(), are now available via the Kernel DDI. Little Things Of course all the big new features got documented, and some major efforts were put into refactoring and renovation, but there were also a lot of smaller things that got fixed as well in the nearly a year between the Solaris 11 and 11.1 doc releases - again too many to list here, but a random sampling of the ones I know about & found interesting or useful: The Privileges section of the DTrace Guide now gives users a pointer to find out how to set up DTrace privileges for non-global zones and what limitations are in place there. A new section on Recommended iSCSI Configuration Practices was added to the iSCSI configuration section when it moved into the SAN Configuration and Multipathing administration guide. The Managing System Power Services section contains an expanded explanation of the various tunables for power management in Solaris 11.1. The sample dcmd sources in /usr/demo/mdb were updated to include ::help output, so that developers like myself who follow the examples don't forget to include it (until a helpful code reviewer pointed it out while reviewing the mdb module changes for Xorg 1.12). The README file in that directory was updated to show the correct paths for installing both kernel & userspace modules, including the 64-bit variants.

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  • To My 24 Year Old Self, Wherever You Are&hellip;

    - by D'Arcy Lussier
    A decade is a milestone in one’s life, regardless of when it occurs. 2011 might seem like a weird year to mark a decade, but 2001 was a defining year for me. It marked my emergence into the technology industry, an unexpected loss of innocence, and triggered an ongoing struggle with faith and belief. Once you go through a valley, climbing the mountain and looking back over where you travelled, you can take in the entirety of the journey. Over the last 10 years I kept journals, and in this new year I took some time to review them. For those today that are me a decade ago, I share with you what I’ve gleamed from my experiences. Take it for what it’s worth, and safe travels on your own journeys through life. Life is a Performance-Based Sport Have confidence, believe you’re capable, but realize that life is a performance-based sport. Everything you get in life is based on whether you can show that you deserve it. Performance is also your best defense against personal attacks. Just make sure you know what standards you’re expected to hit and if people want to poke holes at you let them do the work of trying to find them. Sometimes performance won’t matter though. Good things will happen to bad people, and bad things to good people. What’s important is that you do the right things and ensure the good and bad even out in your own life. How you finish is just as important as how you start. Start strong, end strong. Respect is Your Most Prized Reward Respect is more important than status or ego. The formula is simple: Performing Well + Building Trust + Showing Dedication = Respect Focus on perfecting your craft and helping your team and respect will come. Life is a Team Sport Whatever aspect of your life, you can’t do it alone. You need to rely on the people around you and ensure you’re a positive aspect of their lives; even those that may be difficult or unpleasant. Avoid criticism and instead find ways to help colleagues and superiors better whatever environment you’re in (work, home, etc.). Don’t just highlight gaps and issues, but also come to the table with solutions. At the same time though, stand up for yourself and hold others accountable for the commitments they make to the team. A healthy team needs accountability. Give feedback early and often, and make it verbal. Issues should be dealt with immediately, and positives should be celebrated as they happen. Life is a Contact Sport Difficult moments will happen. Don’t run from them or shield yourself from experiencing them. Embrace them. They will further mold you and reveal who you will become. Find Your Tribe and Embrace Your Community We all need a tribe: a group of people that we gravitate to for support, guidance, wisdom, and friendship. Discover your tribe and immerse yourself in them. Don’t look for a non-existent tribe just to fill the need of belonging though that will leave you empty and bitter when they don’t meet your unrealistic expectations. Try to associate with people more experienced and more knowledgeable than you. You’ll always learn, and you’ll always remember you have much to learn. Put yourself out there, get involved with the community. Opportunities will present themselves. When we open ourselves up to be vulnerable, we also give others the chance to do the same. This helps us all to grow and help each other, it’s very important. And listen to your wife. (Easter *is* a romantic holiday btw, regardless of what you may think.) Don’t Believe Your Own Press Clippings (and by that I mean the ones you write) Until you have a track record of performance to refer to, any notions of grandeur are just that: notions. You lose your rookie status through trials and tribulations, not by the number of stamps in your passport. Be realistic about your own “experience and leadership” and be honest when you aren’t ready for something. And always remember: nobody really cares about you as much as you think they do. Don’t Let Assholes Get You Down The world isn’t evil, but there is evil in the world. Know the difference and don’t paint all people with the same brush. Do be wary of those that use personal beliefs to describe their business (i.e. “We’re a [religion] company”). What matters is the culture of the organization, and that will tell you the moral compass and what is truly valued. Don’t make someone or something a priority that only makes you an option. Life is unfair and enemies/opponents will succeed when you fail. Don’t waste your energy getting upset at this; the only one that will lose out is you. As mentioned earlier, nobody really cares about you as much as you think they do. Misc Ecclesiastes is bullshit. Everything is certainly *not* meaningless. Software development is about delivery, not the process. Having a great process means nothing if you don’t produce anything. Watch “The Weatherman” (“It’s not easy, but easy doesn’t enter into grownup life.”). Read Tony Dungee’s autobiography, even if you don’t like football, and even if you aren’t a Christian. Say no, don’t feel like you have to commit right away when someone asks you to.

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  • SQL Server - Rebuilding Indexes

    - by Renso
    Goal: Rebuild indexes in SQL server. This can be done one at a time or with the example script below to rebuild all index for a specified table or for all tables in a given database. Why? The data in indexes gets fragmented over time. That means that as the index grows, the newly added rows to the index are physically stored in other sections of the allocated database storage space. Kind of like when you load your Christmas shopping into the trunk of your car and it is full you continue to load some on the back seat, in the same way some storage buffer is created for your index but once that runs out the data is then stored in other storage space and your data in your index is no longer stored in contiguous physical pages. To access the index the database manager has to "string together" disparate fragments to create the full-index and create one contiguous set of pages for that index. Defragmentation fixes that. What does the fragmentation affect?Depending of course on how large the table is and how fragmented the data is, can cause SQL Server to perform unnecessary data reads, slowing down SQL Server’s performance.Which index to rebuild?As a rule consider that when reorganize a table's clustered index, all other non-clustered indexes on that same table will automatically be rebuilt. A table can only have one clustered index.How to rebuild all the index for one table:The DBCC DBREINDEX command will not automatically rebuild all of the indexes on a given table in a databaseHow to rebuild all indexes for all tables in a given database:USE [myDB]    -- enter your database name hereDECLARE @tableName varchar(255)DECLARE TableCursor CURSOR FORSELECT table_name FROM information_schema.tablesWHERE table_type = 'base table'OPEN TableCursorFETCH NEXT FROM TableCursor INTO @tableNameWHILE @@FETCH_STATUS = 0BEGINDBCC DBREINDEX(@tableName,' ',90)     --a fill factor of 90%FETCH NEXT FROM TableCursor INTO @tableNameENDCLOSE TableCursorDEALLOCATE TableCursorWhat does this script do?Reindexes all indexes in all tables of the given database. Each index is filled with a fill factor of 90%. While the command DBCC DBREINDEX runs and rebuilds the indexes, that the table becomes unavailable for use by your users temporarily until the rebuild has completed, so don't do this during production  hours as it will create a shared lock on the tables, although it will allow for read-only uncommitted data reads; i.e.e SELECT.What is the fill factor?Is the percentage of space on each index page for storing data when the index is created or rebuilt. It replaces the fill factor when the index was created, becoming the new default for the index and for any other nonclustered indexes rebuilt because a clustered index is rebuilt. When fillfactor is 0, DBCC DBREINDEX uses the fill factor value last specified for the index. This value is stored in the sys.indexes catalog view. If fillfactor is specified, table_name and index_name must be specified. If fillfactor is not specified, the default fill factor, 100, is used.How do I determine the level of fragmentation?Run the DBCC SHOWCONTIG command. However this requires you to specify the ID of both the table and index being. To make it a lot easier by only requiring you to specify the table name and/or index you can run this script:DECLARE@ID int,@IndexID int,@IndexName varchar(128)--Specify the table and index namesSELECT @IndexName = ‘index_name’    --name of the indexSET @ID = OBJECT_ID(‘table_name’)  -- name of the tableSELECT @IndexID = IndIDFROM sysindexesWHERE id = @ID AND name = @IndexName--Show the level of fragmentationDBCC SHOWCONTIG (@id, @IndexID)Here is an example:DBCC SHOWCONTIG scanning 'Tickets' table...Table: 'Tickets' (1829581556); index ID: 1, database ID: 13TABLE level scan performed.- Pages Scanned................................: 915- Extents Scanned..............................: 119- Extent Switches..............................: 281- Avg. Pages per Extent........................: 7.7- Scan Density [Best Count:Actual Count].......: 40.78% [115:282]- Logical Scan Fragmentation ..................: 16.28%- Extent Scan Fragmentation ...................: 99.16%- Avg. Bytes Free per Page.....................: 2457.0- Avg. Page Density (full).....................: 69.64%DBCC execution completed. If DBCC printed error messages, contact your system administrator.What's important here?The Scan Density; Ideally it should be 100%. As time goes by it drops as fragmentation occurs. When the level drops below 75%, you should consider re-indexing.Here are the results of the same table and clustered index after running the script:DBCC SHOWCONTIG scanning 'Tickets' table...Table: 'Tickets' (1829581556); index ID: 1, database ID: 13TABLE level scan performed.- Pages Scanned................................: 692- Extents Scanned..............................: 87- Extent Switches..............................: 86- Avg. Pages per Extent........................: 8.0- Scan Density [Best Count:Actual Count].......: 100.00% [87:87]- Logical Scan Fragmentation ..................: 0.00%- Extent Scan Fragmentation ...................: 22.99%- Avg. Bytes Free per Page.....................: 639.8- Avg. Page Density (full).....................: 92.10%DBCC execution completed. If DBCC printed error messages, contact your system administrator.What's different?The Scan Density has increased from 40.78% to 100%; no fragmentation on the clustered index. Note that since we rebuilt the clustered index, all other index were also rebuilt.

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  • Generically correcting data before save with Entity Framework

    - by koevoeter
    Been working with Entity Framework (.NET 4.0) for a week now for a data migration job and needed some code that generically corrects string values in the database. You probably also have seen things like empty strings instead of NULL or non-trimmed texts ("United States       ") in "old" databases, and you don't want to apply a correcting function on every column you migrate. Here's how I've done this (extending the partial class of my ObjectContext):public partial class MyDatacontext{    partial void OnContextCreated()    {        SavingChanges += OnSavingChanges;    }     private void OnSavingChanges(object sender, EventArgs e)    {        foreach (var entity in GetPersistingEntities(sender))        {            foreach (var propertyInfo in GetStringProperties(entity))            {                var value = (string)propertyInfo.GetValue(entity, null);                 if (value == null)                {                    continue;                }                 if (value.Trim().Length == 0 && IsNullable(propertyInfo))                {                    propertyInfo.SetValue(entity, null, null);                }                else if (value != value.Trim())                {                    propertyInfo.SetValue(entity, value.Trim(), null);                }            }        }    }     private IEnumerable<object> GetPersistingEntities(object sender)    {        return ((ObjectContext)sender).ObjectStateManager            .GetObjectStateEntries(EntityState.Added | EntityState.Modified)             .Select(e => e.Entity);    }    private IEnumerable<PropertyInfo> GetStringProperties(object entity)    {        return entity.GetType().GetProperties()            .Where(pi => pi.PropertyType == typeof(string));    }    private bool IsNullable(PropertyInfo propertyInfo)    {        return ((EdmScalarPropertyAttribute)propertyInfo             .GetCustomAttributes(typeof(EdmScalarPropertyAttribute), false)            .Single()).IsNullable;    }}   Obviously you can use similar code for other generic corrections.

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  • "Imprinting" as a language feature?

    - by MKO
    Idea I had this idea for a language feature that I think would be useful, does anyone know of a language that implements something like this? The idea is that besides inheritance a class can also use something called "imprinting" (for lack of better term). A class can imprint one or several (non-abstract) classes. When a class imprints another class it gets all it's properties and all it's methods. It's like the class storing an instance of the imprinted class and redirecting it's methods/properties to it. A class that imprints another class therefore by definition also implements all it's interfaces and it's abstract class. So what's the point? Well, inheritance and polymorphism is hard to get right. Often composition gives far more flexibility. Multiple inheritance offers a slew of different problems without much benefits (IMO). I often write adapter classes (in C#) by implementing some interface and passing along the actual methods/properties to an encapsulated object. The downside to that approach is that if the interface changes the class breaks. You also you have to put in a lot of code that does nothing but pass things along to the encapsulated object. A classic example is that you have some class that implements IEnumerable or IList and contains an internal class it uses. With this technique things would be much easier Example (c#) [imprint List<Person> as peopleList] public class People : PersonBase { public void SomeMethod() { DoSomething(this.Count); //Count is from List } } //Now People can be treated as an List<Person> People people = new People(); foreach(Person person in people) { ... } peopleList is an alias/variablename (of your choice)used internally to alias the instance but can be skipped if not needed. One thing that's useful is to override an imprinted method, that could be achieved with the ordinary override syntax public override void Add(Person person) { DoSomething(); personList.Add(person); } note that the above is functional equivalent (and could be rewritten by the compiler) to: public class People : PersonBase , IList<Person> { private List<Person> personList = new List<Person>(); public override void Add(object obj) { this.personList.Add(obj) } public override int IndexOf(object obj) { return personList.IndexOf(obj) } //etc etc for each signature in the interface } only if IList changes your class will break. IList won't change but an interface that you, someone in your team, or a thirdparty has designed might just change. Also this saves you writing a whole lot of code for some interfaces/abstract classes. Caveats There's a couple of gotchas. First we, syntax must be added to call the imprinted classes's constructors from the imprinting class constructor. Also, what happends if a class imprints two classes which have the same method? In that case the compiler would detect it and force the class to define an override of that method (where you could chose if you wanted to call either imprinted class or both) So what do you think, would it be useful, any caveats? It seems it would be pretty straightforward to implement something like that in the C# language but I might be missing something :) Sidenote - Why is this different from multiple inheritance Ok, so some people have asked about this. Why is this different from multiple inheritance and why not multiple inheritance. In C# methods are either virtual or not. Say that we have ClassB who inherits from ClassA. ClassA has the methods MethodA and MethodB. ClassB overrides MethodA but not MethodB. Now say that MethodB has a call to MethodA. if MethodA is virtual it will call the implementation that ClassB has, if not it will use the base class, ClassA's MethodA and you'll end up wondering why your class doesn't work as it should. By the terminology sofar you might already confused. So what happens if ClassB inherits both from ClassA and another ClassC. I bet both programmers and compilers will be scratching their heads. The benefit of this approach IMO is that the imprinting classes are totally encapsulated and need not be designed with multiple inheritance in mind. You can basically imprint anything.

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  • Objects won't render when Texture Compression + Mipmapping is Enabled

    - by felipedrl
    I'm optimizing my game and I've just implemented compressed (DXTn) texture loading in OpenGL. I've worked my way removing bugs but I can't figure out this one: objects w/ DXTn + mipmapped textures are not being rendered. It's not like they are appearing with a flat color, they just don't appear at all. DXTn textured objs render and mipmapped non-compressed textures render just fine. The texture in question is 256x256 I generate the mips all the way down 4x4, i.e 1 block. I've checked on gDebugger and it display all the levels (7) just fine. I'm using GL_LINEAR_MIPMAP_NEAREST for min filter and GL_LINEAR for mag one. The texture is being compressed and mipmaps being created offline with Paint.NET tool using super sampling method. (I also tried bilinear just in case) Source follow: [SNIPPET 1: Loading DDS into sys memory + Initializing Object] // Read header DDSHeader header; file.read(reinterpret_cast<char*>(&header), sizeof(DDSHeader)); uint pos = static_cast<uint>(file.tellg()); file.seekg(0, std::ios_base::end); uint dataSizeInBytes = static_cast<uint>(file.tellg()) - pos; file.seekg(pos, std::ios_base::beg); // Read file data mData = new unsigned char[dataSizeInBytes]; file.read(reinterpret_cast<char*>(mData), dataSizeInBytes); file.close(); mMipmapCount = header.mipmapcount; mHeight = header.height; mWidth = header.width; mCompressionType = header.pf.fourCC; // Only support files divisible by 4 (for compression blocks algorithms) massert(mWidth % 4 == 0 && mHeight % 4 == 0); massert(mCompressionType == NO_COMPRESSION || mCompressionType == COMPRESSION_DXT1 || mCompressionType == COMPRESSION_DXT3 || mCompressionType == COMPRESSION_DXT5); // Allow textures up to 65536x65536 massert(header.mipmapcount <= MAX_MIPMAP_LEVELS); mTextureFilter = TextureFilter::LINEAR; if (mMipmapCount > 0) { mMipmapFilter = MipmapFilter::NEAREST; } else { mMipmapFilter = MipmapFilter::NO_MIPMAP; } mBitsPerPixel = header.pf.bitcount; if (mCompressionType == NO_COMPRESSION) { if (header.pf.flags & DDPF_ALPHAPIXELS) { // The only format supported w/ alpha is A8R8G8B8 massert(header.pf.amask == 0xFF000000 && header.pf.rmask == 0xFF0000 && header.pf.gmask == 0xFF00 && header.pf.bmask == 0xFF); mInternalFormat = GL_RGBA8; mFormat = GL_BGRA; mDataType = GL_UNSIGNED_BYTE; } else { massert(header.pf.rmask == 0xFF0000 && header.pf.gmask == 0xFF00 && header.pf.bmask == 0xFF); mInternalFormat = GL_RGB8; mFormat = GL_BGR; mDataType = GL_UNSIGNED_BYTE; } } else { uint blockSizeInBytes = 16; switch (mCompressionType) { case COMPRESSION_DXT1: blockSizeInBytes = 8; if (header.pf.flags & DDPF_ALPHAPIXELS) { mInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT; } else { mInternalFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT; } break; case COMPRESSION_DXT3: mInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; break; case COMPRESSION_DXT5: mInternalFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; break; default: // Not Supported (DXT2, DXT4 or any compression format) massert(false); } } [SNIPPET 2: Uploading into video memory] massert(mData != NULL); glGenTextures(1, &mHandle); massert(mHandle!=0); glBindTexture(GL_TEXTURE_2D, mHandle); commitFiltering(); uint offset = 0; Renderer* renderer = Renderer::getInstance(); switch (mInternalFormat) { case GL_RGB: case GL_RGBA: case GL_RGB8: case GL_RGBA8: for (uint i = 0; i < mMipmapCount + 1; ++i) { uint width = std::max(1U, mWidth >> i); uint height = std::max(1U, mHeight >> i); glTexImage2D(GL_TEXTURE_2D, i, mInternalFormat, width, height, mHasBorder, mFormat, mDataType, &mData[offset]); offset += width * height * (mBitsPerPixel / 8); } break; case GL_COMPRESSED_RGB_S3TC_DXT1_EXT: case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: { uint blockSize = 16; if (mInternalFormat == GL_COMPRESSED_RGB_S3TC_DXT1_EXT || mInternalFormat == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) { blockSize = 8; } uint width = mWidth; uint height = mHeight; for (uint i = 0; i < mMipmapCount + 1; ++i) { uint nBlocks = ((width + 3) / 4) * ((height + 3) / 4); // Only POT textures allowed for mipmapping massert(width % 4 == 0 && height % 4 == 0); glCompressedTexImage2D(GL_TEXTURE_2D, i, mInternalFormat, width, height, mHasBorder, nBlocks * blockSize, &mData[offset]); offset += nBlocks * blockSize; if (width <= 4 && height <= 4) { break; } width = std::max(4U, width / 2); height = std::max(4U, height / 2); } break; } default: // Not Supported massert(false); } Also I don't understand the "+3" in the block size computation but looking for a solution for my problema I've encountered people defining it as that. I guess it won't make a differente for POT textures but I put just in case. Thanks.

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  • OpenGL 3 and the Radeon HD 4850x2

    - by rotard
    A while ago, I picked up a copy of the OpenGL SuperBible fifth edition and slowly and painfully started teaching myself OpenGL the 3.3 way, after having been used to the 1.0 way from school way back when. Making things more challenging, I am primarily a .NET developer, so I was working in Mono with the OpenTK OpenGL wrapper. On my laptop, I put together a program that let the user walk around a simple landscape using a couple shaders that implemented per-vertex coloring and lighting and texture mapping. Everything was working brilliantly until I ran the same program on my desktop. Disaster! Nothing would render! I have chopped my program down to the point where the camera sits near the origin, pointing at the origin, and renders a square (technically, a triangle fan). The quad renders perfectly on my laptop, coloring, lighting, texturing and all, but the desktop renders a small distorted non-square quadrilateral that is colored incorrectly, not affected by the lights, and not textured. I suspect the graphics card is at fault, because I get the same result whether I am booted into Ubuntu 10.10 or Win XP. I did find that if I pare the vertex shader down to ONLY outputting the positional data and the fragment shader to ONLY outputting a solid color (white) the quad renders correctly. But as SOON as I start passing in color data (whether or not I use it in the fragment shader) the output from the vertex shader is distorted again. The shaders follow. I left the pre-existing code in, but commented out so you can get an idea what I was trying to do. I'm a noob at glsl so the code could probably be a lot better. My laptop is an old lenovo T61p with a Centrino (Core 2) Duo and an nVidia Quadro graphics card running Ubuntu 10.10 My desktop has an i7 with a Radeon HD 4850 x2 (single card, dual GPU) from Saphire dual booting into Ubuntu 10.10 and Windows XP. The problem occurs in both XP and Ubuntu. Can anyone see something wrong that I am missing? What is "special" about my HD 4850x2? string vertexShaderSource = @" #version 330 precision highp float; uniform mat4 projection_matrix; uniform mat4 modelview_matrix; //uniform mat4 normal_matrix; //uniform mat4 cmv_matrix; //Camera modelview. Light sources are transformed by this matrix. //uniform vec3 ambient_color; //uniform vec3 diffuse_color; //uniform vec3 diffuse_direction; in vec4 in_position; in vec4 in_color; //in vec3 in_normal; //in vec3 in_tex_coords; out vec4 varyingColor; //out vec3 varyingTexCoords; void main(void) { //Get surface normal in eye coordinates //vec4 vEyeNormal = normal_matrix * vec4(in_normal, 0); //Get vertex position in eye coordinates //vec4 vPosition4 = modelview_matrix * vec4(in_position, 0); //vec3 vPosition3 = vPosition4.xyz / vPosition4.w; //Get vector to light source in eye coordinates //vec3 lightVecNormalized = normalize(diffuse_direction); //vec3 vLightDir = normalize((cmv_matrix * vec4(lightVecNormalized, 0)).xyz); //Dot product gives us diffuse intensity //float diff = max(0.0, dot(vEyeNormal.xyz, vLightDir.xyz)); //Multiply intensity by diffuse color, force alpha to 1.0 //varyingColor.xyz = in_color * diff * diffuse_color.xyz; varyingColor = in_color; //varyingTexCoords = in_tex_coords; gl_Position = projection_matrix * modelview_matrix * in_position; }"; string fragmentShaderSource = @" #version 330 //#extension GL_EXT_gpu_shader4 : enable precision highp float; //uniform sampler2DArray colorMap; //in vec4 varyingColor; //in vec3 varyingTexCoords; out vec4 out_frag_color; void main(void) { out_frag_color = vec4(1,1,1,1); //out_frag_color = varyingColor; //out_frag_color = vec4(varyingColor, 1) * texture(colorMap, varyingTexCoords.st); //out_frag_color = vec4(varyingColor, 1) * texture(colorMap, vec3(varyingTexCoords.st, 0)); //out_frag_color = vec4(varyingColor, 1) * texture2DArray(colorMap, varyingTexCoords); }"; Note that in this code the color data is accepted but not actually used. The geometry is outputted the same (wrong) whether the fragment shader uses varyingColor or not. Only if I comment out the line varyingColor = in_color; does the geometry output correctly. Originally the shaders took in vec3 inputs, I only modified them to take vec4s while troubleshooting.

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  • A Patent for Workload Management Based on Service Level Objectives

    - by jsavit
    I'm very pleased to announce that after a tiny :-) wait of about 5 years, my patent application for a workload manager was finally approved. Background Many operating systems have a resource manager which lets you control machine resources. For example, Solaris provides controls for CPU with several options: shares for proportional CPU allocation. If you have twice as many shares as me, and we are competing for CPU, you'll get about twice as many CPU cycles), dedicated CPU allocation in which a number of CPUs are exclusively dedicated to an application's use. You can say that a zone or project "owns" 8 CPUs on a 32 CPU machine, for example. And, capped CPU in which you specify the upper bound, or cap, of how much CPU an application gets. For example, you can throttle an application to 0.125 of a CPU. (This isn't meant to be an exhaustive list of Solaris RM controls.) Workload management Useful as that is (and tragic that some other operating systems have little resource management and isolation, and frighten people into running only 1 app per OS instance - and wastefully size every server for the peak workload it might experience) that's not really workload management. With resource management one controls the resources, and hope that's enough to meet application service objectives. In fact, we hold resource distribution constant, see if that was good enough, and adjust resource distribution if that didn't meet service level objectives. Here's an example of what happens today: Let's try 30% dedicated CPU. Not enough? Let's try 80% Oh, that's too much, and we're achieving much better response time than the objective, but other workloads are starving. Let's back that off and try again. It's not the process I object to - it's that we to often do this manually. Worse, we sometimes identify and adjust the wrong resource and fiddle with that to no useful result. Back in my days as a customer managing large systems, one of my users would call me up to beg for a "CPU boost": Me: "it won't make any difference - there's plenty of spare CPU to be had, and your application is completely I/O bound." User: "Please do it anyway." Me: "oh, all right, but it won't do you any good." (I did, because he was a friend, but it didn't help.) Prior art There are some operating environments that take a stab about workload management (rather than resource management) but I find them lacking. I know of one that uses synthetic "service units" composed of the sum of CPU, I/O and memory allocations multiplied by weighting factors. A workload is set to make a target rate of service units consumed per second. But this seems to be missing a key point: what is the relationship between artificial 'service units' and actually meeting a throughput or response time objective? What if I get plenty of one of the components (so am getting enough service units), but not enough of the resource whose needed to remove the bottleneck? Actual workload management That's not really the answer either. What is needed is to specify a workload's service levels in terms of externally visible metrics that are meaningful to a business, such as response times or transactions per second, and have the workload manager figure out which resources are not being adequately provided, and then adjust it as needed. If an application is not meeting its service level objectives and the reason is that it's not getting enough CPU cycles, adjust its CPU resource accordingly. If the reason is that the application isn't getting enough RAM to keep its working set in memory, then adjust its RAM assignment appropriately so it stops swapping. Simple idea, but that's a task we keep dumping on system administrators. In other words - don't hold the number of CPU shares constant and watch the achievement of service level vary. Instead, hold the service level constant, and dynamically adjust the number of CPU shares (or amount of other resources like RAM or I/O bandwidth) in order to meet the objective. Instrumenting non-instrumented applications There's one little problem here: how do I measure application performance in a way relating to a service level. I don't want to do it based on internal resources like number of CPU seconds it received per minute - We need to make resource decisions based on externally visible and meaningful measures of performance, not synthetic items or internal resource counters. If I have a way of marking the beginning and end of a transaction, I can then measure whether or not the application is meeting an objective based on it. If I can observe the delay factors for an application, I can see which resource shortages are slowing an application enough to keep it from meeting its objectives. I can then adjust resource allocations to relieve those shortages. Fortunately, Solaris provides facilities for both marking application progress and determining what factors cause application latency. The Solaris DTrace facility let's me introspect on application behavior: in particular I can see events like "receive a web hit" and "respond to that web hit" so I can get transaction rate and response time. DTrace (and tools like prstat) let me see where latency is being added to an application, so I know which resource to adjust. Summary After a delay of a mere few years, I am the proud creator of a patent (advice to anyone interested in going through the process: don't hold your breath!). The fundamental idea is fairly simple: instead of holding resource constant and suffering variable levels of success meeting service level objectives, properly characterise the service level objective in meaningful terms, instrument the application to see if it's meeting the objective, and then have a workload manager change resource allocations to remove delays preventing service level attainment. I've done it by hand for a long time - I think that's what a computer should do for me.

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  • Data Source Security Part 5

    - by Steve Felts
    If you read through the first four parts of this series on data source security, you should be an expert on this focus area.  There is one more small topic to cover related to WebLogic Resource permissions.  After that comes the test, I mean example, to see with a real set of configuration parameters what the results are with some concrete values. WebLogic Resource Permissions All of the discussion so far has been about database credentials that are (eventually) used on the database side.  WLS has resource credentials to control what WLS users are allowed to access JDBC resources.  These can be defined on the Policies tab on the Security tab associated with the data source.  There are four permissions: “reserve” (get a new connection), “admin”, “shrink”, and reset (plus the all-inclusive “ALL”); we will focus on “reserve” here because we are talking about getting connections.  By default, JDBC resource permissions are completely open – anyone can do anything.  As soon as you add one policy for a permission, then all other users are restricted.  For example, if I add a policy so that “weblogic” can reserve a connection, then all other users will fail to reserve connections unless they are also explicitly added.  The validation is done for WLS user credentials only, not database user credentials.  Configuration of resources in general is described at “Create policies for resource instances” http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/security/CreatePoliciesForResourceInstances.html.  This feature can be very useful to restrict what code and users can get to your database. There are the three use cases: API Use database credentials User for permission checking getConnection() True or false Current WLS user getConnection(user,password) False User/password from API getConnection(user,password) True Current WLS user If a simple getConnection() is used or database credentials are enabled, the current user that is authenticated to the WLS system is checked. If database credentials are not enabled, then the user and password on the API are used. Example The following is an actual example of the interactions between identity-based-connection-pooling-enabled, oracle-proxy-session, and use-database-credentials. On the database side, the following objects are configured.- Database users scott; jdbcqa; jdbcqa3- Permission for proxy: alter user jdbcqa3 grant connect through jdbcqa;- Permission for proxy: alter user jdbcqa grant connect through jdbcqa; The following WebLogic Data Source objects are configured.- Users weblogic, wluser- Credential mapping “weblogic” to “scott”- Credential mapping "wluser" to "jdbcqa3"- Data source descriptor configured with user “jdbcqa”- All tests are run with Set Client ID set to true (more about that below).- All tests are run with oracle-proxy-session set to false (more about that below). The test program:- Runs in servlet- Authenticates to WLS as user “weblogic” Use DB Credentials Identity based getConnection(scott,***) getConnection(weblogic,***) getConnection(jdbcqa3,***) getConnection()  true  true Identity scottClient weblogicProxy null weblogic fails - not a db user User jdbcqa3Client weblogicProxy null Default user jdbcqaClient weblogicProxy null  false  true scott fails - not a WLS user User scottClient scottProxy null jdbcqa3 fails - not a WLS user User scottClient scottProxy null  true  false Proxy for scott fails weblogic fails - not a db user User jdbcqa3Client weblogicProxy jdbcqa Default user jdbcqaClient weblogicProxy null  false  false scott fails - not a WLS user Default user jdbcqaClient scottProxy null jdbcqa3 fails - not a WLS user Default user jdbcqaClient scottProxy null If Set Client ID is set to false, all cases would have Client set to null. If this was not an Oracle thin driver, the one case with the non-null Proxy in the above table would throw an exception because proxy session is only supported, implicitly or explicitly, with the Oracle thin driver. When oracle-proxy-session is set to true, the only cases that will pass (with a proxy of "jdbcqa") are the following.1. Setting use-database-credentials to true and doing getConnection(jdbcqa3,…) or getConnection().2. Setting use-database-credentials to false and doing getConnection(wluser, …) or getConnection(). Summary There are many options to choose from for data source security.  Considerations include the number and volatility of WLS and Database users, the granularity of data access, the depth of the security identity (property on the connection or a real user), performance, coordination of various components in the software stack, and driver capabilities.  Now that you have the big picture (remember that table in part 1), you can make a more informed choice.

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  • "Guiding" a Domain Expert to Retire from Programming

    - by James Kolpack
    I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

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  • What do the participants say about the Open Day in South Africa?

    - by Maria Sandu
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 On the 26th of September, a group of students who were specifically selected to attend an Open day at Oracle South Africa, joined us at our offices in Woodmead, Johannesburg. The Conference room was filled with inquisitive minds. What we had in store for them was a detailed presentation about Oracle which was delivered by Zuko - Cluster Leader: Tech GB South Africa. The student’s many questions were all answered especially when we started addressing the opportunities we have and detailed information on our Graduate Programme. Our employees then came to talk about their experience. This allowed all the students to have an integrated learning experience. By inviting the students to walk around our Oracle Offices allowed them to see, talk, experience a bit of the culture and ask more questions. Here is some of the feedback from the attendees: Maxwell Moloi: “The open day truly served its purpose and exceeded expectations in the sense that I got to find out more about Oracle and all the different opportunities it has to offer. The fact that Oracle supplies a full solution to a customer and not just part of it and how the company manages to setup professional development for their employees is what entices me to want to join the rapidly growing team of Oracle.” Nqobile Mabaso: “I found the open day to be quite informative and enlightening because coming from a marketing background I could apply the knowledge I got from varsity to the Company I was able to point out what they do as part of their corporate social responsibility (Oracle recently partnered with the department of education to build a school), how Oracle emphasizes on relationship building because they know they sell to people and not companies and how they offer the full stack of solutions which gives them a competitive advantage over their competitors.” Nondumiso Mvelase: “The Open Day was a wonderful experience for me especially because I have never been part of an Open Day before, so it was absolutely amazing for me. It gave me a good idea of how it is to be part of Oracle. We were served with lovely breakfast and lunch which I enjoyed. I wish the Open Day went on for a whole week. Seeing and hearing from 2013 Graduates, telling us about their experience within Oracle was very inspiring to me. They were encouraging us to work hard if we ever got the opportunity they had. After hearing this from them I will definitely not take it for granted.” Itumeleng Moraka: “Before I walked into the Oracle offices all that was in my mind was databases and cloud storage. I was then surrounded by passionate, enthusiastic and welcoming employees. I came across a positive energy within the multinational company. I realized that Oracle is not a company that operates in survival mode. This may sound idealistic, but they operate in a non-traditional way investing more into innovation, they stay focused on what matters most about where technology is going and at the same time they are not losing sight of how their products make a difference in the world.” For more information on how to be part of the Oracle Graduate Programme please follow us on Facebook! https://www.facebook.com/CampusAtOracle /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Yes, I did it - Skydiving in Mauritius

    Finally, I did it or better said we did it. Already back in November last year I saw the big billboard advertisement of Skydive Austral Mauritius near Caudan Waterfront in Port Louis and decided for myself that this is going to be the perfect birthday gift for my wife. Simply out of curiosity I would join her tandem jump with a second instructor. Due to her pregnancy of our son I had to be patient... But then finally, her birthday had arrived and on our midnight celebration session I showed her her netbook with the website preloaded. Actually, it was the "perfect" timing... Recovery from her cesarean is fine, local weather conditions are gorgious and the children were under surveillance of my mum - spending her annual holidays on the island. So, after late wake-up in the morning, we packed our stuff and off we went. According to Google Maps direction indication we had to drive for roughly 50km (only) but traffic here in Mauritius is always challenging. The dropzone is at the Zone Industrielle Mon Loisir Sugar Estate near Riviere du Rempart at the northern east coast. Anyways, we were not in a hurry and arrived there shortly after noon. The access road to the airfield are just small down-driven paths through sugar cane fields and according to our daughter "it's bumpy!". True true true... The facilities at Skydive Austral Mauritius are complete except for food. Enough space for parking, easy handling at the reception and a lot to see for the kids. There's even a big terrace with several sets of tables and chairs, small bar for soft drinks, strictly non-alcoholic. The team over there is all welcoming and warm-hearthy! Having the kids with us was no issue at all. Quite the opposite, our daugther was allowed to discover a lot of things than we adults did. Even visiting the small air plane was on the menu for her. Really great stuff! While waiting for our turn we enjoyed watching other people getting ready in the jump gear, taking off with the Cessna, and finally coming back down on the tandem parachute. Actually, the different expressions on their faces was one of the best parts while waiting. Great mental preparation as my wife was getting more anxious about her first jump... {loadposition content_adsense} First, we got some information about the procedures on the plane about how to get seated, tight up with our instructors and how to get ready for the jump off the plane as soon as we arrive the height of 10.000 ft. All well explained and easy to understand after all.Next, we met with our jumpers Chris and Lee aka "Rasta" to get dressed and ready for take-off. Those guys are really cool and relaxed for their job. From that point on, the DVD session / recording for my wife's birthday started and we really had a lot of fun... The difference between that small Cessna and a commercial flight with an Airbus or a Boeing is astronomic! The climb up to 10.000 ft took us roughly 25 minutes and we enjoyed the magnificent view over the turquoise lagunes near Poste de Flacq, Lafayette and Isle d'Ambre on the north-east coast. After flying through the clouds we sun-bathed and looked over "iced-sugar covered" Mauritius. You might have a look at the picture gallery of Skydive Mauritius for better imagination. The moment of truth, or better said, point of no return came after approximately 25 minutes. The door opens, moving into position on the side on top of the wheel and... out! Back flip and free fall! Slight turns and Wooooohooooo! through the clouds... It so amazing and breath-taking! So undescribable! You have to experience this yourself! Some seconds later the parachute opened and we glided smoothly with some turns and spins back down to the dropzone. The rest of the family could hear and see us soon and the landing was easy going. We never had any doubts or fear about our instructors. They did a great job and we are looking forward to book our next job. I might even consider to follow educational classes on skydiving and earn a license. By the way, feel free to get in touch with Skydive Austral Mauritius. Either via contact details on their website or tweeting a little bit with them. Follow the tweets of Chris and fellows on SkydiveAustral.

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  • The Best BPM Journey: More Exciting Destinations with Process Accelerators

    - by Cesare Rotundo
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Oracle Open World (OOW) earlier this month has been a great occasion to discuss with our BPM customers. It was interesting to hear definite patterns emerging from those conversations: “BPM is a journey”, “experiences to share”, “our organization now understands what BPM is”, and my favorite (with some caveats): “BPM is like wine tasting, once you start, you want to try more”. These customers have started their journey, climbed up the learning curve, and reached a vantage point that allows them to see their next BPM destination. They see the next few processes they are going to tackle and improve with BPM. These processes/destinations target both horizontal processes where BPM replaces or coordinates manual activities, and critical industry processes that the company needs to improve to compete and deliver increasing value. Each new destination generates value, allowing the organization to reduce the cost of manual processes that were not supported by apps/custom development, and increase efficiency of end-to-end processes partially covered by apps/custom dev. The question we wanted to answer is how to help organizations experience deeper success with BPM, by increasing their awareness of the potential for reaching new targets, and equipping them with the right tools. We decided that we needed to identify destinations, and plot routes to show the fastest path to those destinations. In the end we want to enable customers to reach “Process Excellence”: continuously set new targets and consistently and efficiently reach them. The result is Oracle Process Accelerators (PA), solutions built using the rich functionality in Oracle BPM Suite. PAs offers a rapidly expanding list of exciting destinations. Our launch of the latest installment of Process Accelerators at Oracle Open World includes new Industry-focused solutions such as Public Sector Incident Reporting and Financial Services Loan Origination, and improved other horizontal PAs, including Travel Request Management, Document Routing and Approval, and Internal Service Requests. Just before OOW we had extended the Oracle deployment of Travel Request Management, riding the enthusiastic response from early adopters among travelers (employees), management and support (approvers). “Getting there first” means being among the first to extract value from the PA approach, while acquiring deeper insights into the customers’ perspective. This is especially noteworthy when it comes to PAs, a set of solutions designed to be quickly deployed and iteratively improved by customers. The OOW launch has generated immediate feedback from customers, non-customers, analysts, and partners. They all confirmed that both Business and IT at organizations benefit from PAs when it comes to exploring the potential for BPM to improve their business processes. PAs help customers visualize what can be done with BPM, and PAs are made to be extended: you can see your destination, change the path to fit your needs, and deploy. We're discovering new destinations/processes that the market wants us to support, generic enough across industries and within industries. We'll keep on building sets of requirements, deliver functional design, construct solutions using Oracle BPM, and test them not only functionally but for performance, scalability, clustering, making them robust, product-quality. Delivering BPM solutions with product-grade quality is the equivalent of following a tried-and-tested path on a map. Do you know of existing destinations in your industry? If yes, we can draw a path to innovative processes together.

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  • How to make creating viewmodels at runtime less painfull

    - by Mr Happy
    I apologize for the long question, it reads a bit as a rant, but I promise it's not! I've summarized my question(s) below In the MVC world, things are straightforward. The Model has state, the View shows the Model, and the Controller does stuff to/with the Model (basically), a controller has no state. To do stuff the Controller has some dependencies on web services, repository, the lot. When you instantiate a controller you care about supplying those dependencies, nothing else. When you execute an action (method on Controller), you use those dependencies to retrieve or update the Model or calling some other domain service. If there's any context, say like some user wants to see the details of a particular item, you pass the Id of that item as parameter to the Action. Nowhere in the Controller is there any reference to any state. So far so good. Enter MVVM. I love WPF, I love data binding. I love frameworks that make data binding to ViewModels even easier (using Caliburn Micro a.t.m.). I feel things are less straightforward in this world though. Let's do the exercise again: the Model has state, the View shows the ViewModel, and the ViewModel does stuff to/with the Model (basically), a ViewModel does have state! (to clarify; maybe it delegates all the properties to one or more Models, but that means it must have a reference to the model one way or another, which is state in itself) To do stuff the ViewModel has some dependencies on web services, repository, the lot. When you instantiate a ViewModel you care about supplying those dependencies, but also the state. And this, ladies and gentlemen, annoys me to no end. Whenever you need to instantiate a ProductDetailsViewModel from the ProductSearchViewModel (from which you called the ProductSearchWebService which in turn returned IEnumerable<ProductDTO>, everybody still with me?), you can do one of these things: call new ProductDetailsViewModel(productDTO, _shoppingCartWebService /* dependcy */);, this is bad, imagine 3 more dependencies, this means the ProductSearchViewModel needs to take on those dependencies as well. Also changing the constructor is painfull. call _myInjectedProductDetailsViewModelFactory.Create().Initialize(productDTO);, the factory is just a Func, they are easily generated by most IoC frameworks. I think this is bad because Init methods are a leaky abstraction. You also can't use the readonly keyword for fields that are set in the Init method. I'm sure there are a few more reasons. call _myInjectedProductDetailsViewModelAbstractFactory.Create(productDTO); So... this is the pattern (abstract factory) that is usually recommended for this type of problem. I though it was genious since it satisfies my craving for static typing, until I actually started using it. The amount of boilerplate code is I think too much (you know, apart from the ridiculous variable names I get use). For each ViewModel that needs runtime parameters you'll get two extra files (factory interface and implementation), and you need to type the non-runtime dependencies like 4 extra times. And each time the dependencies change, you get to change it in the factory as well. It feels like I don't even use an DI container anymore. (I think Castle Windsor has some kind of solution for this [with it's own drawbacks, correct me if I'm wrong]). do something with anonymous types or dictionary. I like my static typing. So, yeah. Mixing state and behavior in this way creates a problem which don't exist at all in MVC. And I feel like there currently isn't a really adequate solution for this problem. Now I'd like to observe some things: People actually use MVVM. So they either don't care about all of the above, or they have some brilliant other solution. I haven't found an indepth example of MVVM with WPF. For example, the NDDD-sample project immensely helped me understand some DDD concepts. I'd really like it if someone could point me in the direction of something similar for MVVM/WPF. Maybe I'm doing MVVM all wrong and I should turn my design upside down. Maybe I shouldn't have this problem at all. Well I know other people have asked the same question so I think I'm not the only one. To summarize Am I correct to conclude that having the ViewModel being an integration point for both state and behavior is the reason for some difficulties with the MVVM pattern as a whole? Is using the abstract factory pattern the only/best way to instantiate a ViewModel in a statically typed way? Is there something like an in depth reference implementation available? Is having a lot of ViewModels with both state/behavior a design smell?

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  • Answers to Conference Revenue Tweet Questions

    - by D'Arcy Lussier
    Originally posted on: http://geekswithblogs.net/dlussier/archive/2014/05/27/156612.aspxI tweeted this the other day… …and I had some people tweet back questioning/asking about the profit number. So here’s how I came to that figure. Total Revenue Let’s talk total revenue first. This conference has a huge list of companies/organizations paying some amount for sponsorship. Platinum ($1500) x 5 = $7500 Gold ($1000) x 3 = $3000 Silver ($500) x 9 = $4500 Bronze ($250) x 13 = $3250 There’s also a title sponsor level but there’s no mention of how much that is…more than $1500 though, so let’s just say $2500. Total Sponsorship Revenue: $20750.00 For registrations, this conference is claiming over 300 attendees. We’ll just calculate at 300 and the discounted “member rate” – $249. Total Registration Revenue: $74700.00 Booth space is also sold for a vendor area, but let’s just leave that out of the calculation. Total Event Revenue: $95450.00 Now that we know how much money we’re playing with, let’s knock out the costs for the event. Total Costs Hard Costs Audio/Visual Services $2000 Conference Rooms (4 Breakouts + Plenary) $2500 Insurance $700 Printing/Signage $1500 Travel/Hotel Rooms $2000 Keynotes $2000 So let’s talk about these hard costs first. First you may be asking about the Audio Visual. Yes those services can be that high, actually higher. But since there’s an A/V company touted as the official A/V provider, I gotta think there’s some discount for being branded as such. Conference rooms are actually an inflated amount of $500 per. Venues make money on the food they sell at events, not on room rentals. The more food, the cheaper the rooms tend to be offered at. Still, for the sake of argument, let’s set the rooms at $500 each knowing that they could be lower. For travel and hotel rooms…it appears that most of the speakers at this conference are local, meaning there’s no travel or hotel cost. But a few of them I wasn’t too sure…so let’s factor in enough to cover two outside speakers (airfare and hotel). There are two keynotes for this event and depending on the event those may be paid gigs. I’m not sure if they are or not, but considering the closing one is a comedian I’m going to add some funds here for that just in case. Total Hard Costs: $10700 Now that the hard costs are out of the way, let’s talk about the food costs. Food Costs The conference is providing a continental breakfast (YEEEESH!), some level of luncheon, and I have to assume coffee breaks in between. Let’s look at those costs. Continental Breakfast $12 per person Lunch Buffet $18 per person Coffee Breaks (2) $6 per person (or $3 a cup) Snacks (2) $10 per person (or $5 each) Note that the lunch buffet assumes a *good* lunch buffet – two entrees, starch, vegetable, salads, and bread. Not sure if there’ll be snacks during coffee breaks but let’s assume so. Total Food Cost Per Person: $46 Food Cost: $14950 Gratuity: $2691 Total Food Cost: $17641 Total food cost is based on the $46 per person cost x 325. 300 for attendance, 12 for speakers, extra 13 for volunteers/organizers. Gratuity is 18%. Grand Totals So let’s sum things up here. Total Costs Hard Costs: $10700.00 Food Costs: $17641.00 Total:          $28341.00 Taxes:         $3685.00 Grand Total  $32026.00 Total Revenue Sponsorship  $20750 Registration   $74700 Grand Total   $95450.00 Total Profit $63424.00 Now what if the registration numbers were lower and they only got 100 people to show up. In that scenario there’d still be a profit of just under $26000. Closing Comments A couple of things to note: - I haven’t factored in anything for prizes. Not sure if any will be given out - We didn’t add in the booth space revenue - We’re assuming speakers aren’t getting paid, but even if they were at the high end its $12000 ($1000 per session), which is probably an inflated number for local speakers. - Note that all registrations were set to the “member” discounted price. The non-member registration price is higher. There is also an option for those that just want to show up for the opening keynote. There you have it! Let me know if you have any questions. D

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  • Data Source Security Part 1

    - by Steve Felts
    I’ve written a couple of articles on how to store data source security credentials using the Oracle wallet.  I plan to write a few articles on the various types of security available to WebLogic Server (WLS) data sources.  There are more options than you might think! There have been several enhancements in this area in WLS 10.3.6.  There are a couple of more enhancements planned for release WLS 12.1.2 that I will include here for completeness.  This isn’t intended as a teaser.  If you call your Oracle support person, you can get them now as minor patches to WLS 10.3.6.   The current security documentation is scattered in a few places, has a few incorrect statements, and is missing a few topics.  It also seems that the knowledge of how to apply some of these features isn’t written down.  The goal of these articles is to talk about WLS data source security in a unified way and to introduce some approaches to using the available features.  Introduction to WebLogic Data Source Security Options By default, you define a single database user and password for a data source.  You can store it in the data source descriptor or make use of the Oracle wallet.  This is a very simple and efficient approach to security.  All of the connections in the connection pool are owned by this user and there is no special processing when a connection is given out.  That is, it’s a homogeneous connection pool and any request can get any connection from a security perspective (there are other aspects like affinity).  Regardless of the end user of the application, all connections in the pool use the same security credentials to access the DBMS.   No additional information is needed when you get a connection because it’s all available from the data source descriptor (or wallet). java.sql.Connection conn =  mydatasource.getConnection(); Note: You can enter the password as a name-value pair in the Properties field (this not permitted for production environments) or you can enter it in the Password field of the data source descriptor. The value in the Password field overrides any password value defined in the Properties passed to the JDBC Driver when creating physical database connections. It is recommended that you use the Password attribute in place of the password property in the properties string because the Password value is encrypted in the configuration file (stored as the password-encrypted attribute in the jdbc-driver-params tag in the module file) and is hidden in the administration console.  The Properties and Password fields are located on the administration console Data Source creation wizard or Data Source Configuration tab. The JDBC API can also be used to programmatically specify a database user name and password as in the following.  java.sql.Connection conn = mydatasource.getConnection(“user”, “password”); According to the JDBC specification, it’s supposed to take a database user and associated password but different vendors implement this differently.  WLS, by default, treats this as an application server user and password.  The pair is authenticated to see if it’s a valid user and that user is used for WLS security permission checks.  By default, the user is then mapped to a database user and password using the data source credential mapper, so this API sort of follows the specification but database credentials are one-step removed from the application code.  More details and the rationale are described later. While the default approach is simple, it does mean that only one database user is doing all of the work.  You can’t figure out who actually did the update and you can’t restrict SQL operations by who is running the operation, at least at the database level.   Any type of per-user logic will need to be in the application code instead of having the database do it.  There are various WLS data source features that can be configured to provide some per-user information about the operations to the database. WebLogic Data Source Security Options This table describes the features available for WebLogic data sources to configure database security credentials and a brief description.  It also captures information about the compatibility of these features with one another. Feature Description Can be used with Can’t be used with User authentication (default) Default getConnection(user, password) behavior – validate the input and use the user/password in the descriptor. Set client identifier Proxy Session, Identity pooling, Use database credentials Use database credentials Instead of using the credential mapper, use the supplied user and password directly. Set client identifier, Proxy session, Identity pooling User authentication, Multi Data Source Set Client Identifier Set a client identifier property associated with the connection (Oracle and DB2 only). Everything Proxy Session Set a light-weight proxy user associated with the connection (Oracle-only). Set client identifier, Use database credentials Identity pooling, User authentication Identity pooling Heterogeneous pool of connections owned by specified users. Set client identifier, Use database credentials Proxy session, User authentication, Labeling, Multi-datasource, Active GridLink Note that all of these features are available with both XA and non-XA drivers. Currently, the Proxy Session and Use Database Credentials options are on the Oracle tab of the Data Source Configuration tab of the administration console (even though the Use Database Credentials feature is not just for Oracle databases – oops).  The rest of the features are on the Identity tab of the Data Source Configuration tab in the administration console (plan on seeing them all in one place in the future). The subsequent articles will describe these features in more detail.  Keep referring back to this table to see the big picture.

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  • Exiting a reboot loop

    - by user12617035
    If you're in a situation where the system is panic'ing during boot, you can use # boot net -s to regain control of your system. In my case, I'd added some diagnostic code to a (PCI) driver (that is used to boot the root filesystem). There was a bug in the driver, and each time during boot, the bug occurred, and so caused the system to panic: ... 000000000180b950 genunix:vfs_mountroot+60 (800, 200, 0, 185d400, 1883000, 18aec00) %l0-3: 0000000000001770 0000000000000640 0000000001814000 00000000000008fc %l4-7: 0000000001833c00 00000000018b1000 0000000000000600 0000000000000200 000000000180ba10 genunix:main+98 (18141a0, 1013800, 18362c0, 18ab800, 180e000, 1814000) %l0-3: 0000000070002000 0000000000000001 000000000180c000 000000000180e000 %l4-7: 0000000000000001 0000000001074800 0000000000000060 0000000000000000 skipping system dump - no dump device configured rebooting... If you're logged in via the console, you can send a BREAK sequence in order to gain control of the firmware's (OBP's) prompt. Enter Ctrl-Shift-[ in order to get the TELNET prompt. Once telnet has control, enter this: telnet> send brk You'll be presented with OBP's prompt: ok You then enter the following in order to boot into single-user mode via the network: ok boot net -s Note that booting from the network under Solaris will implicitly cause the system to be INSTALLED with whatever software had last been configured to be installed. However, we are using boot net -s as a "handle" with which to get at the Solaris prompt. Once at that prompt, we can perform actions as root that will let us back out our buggy driver (ok... MY buggy driver :-)) ...and replace it with the original, non-buggy driver. Entering the boot command caused the following output, as well as left us at the Solaris prompt (in single-user-mode): Sun Blade 1500, No Keyboard Copyright 1998-2004 Sun Microsystems, Inc. All rights reserved. OpenBoot 4.16.4, 1024 MB memory installed, Serial #53463393. Ethernet address 0:3:ba:2f:c9:61, Host ID: 832fc961. Rebooting with command: boot net -s Boot device: /pci@1f,700000/network@2 File and args: -s 1000 Mbps FDX Link up Timeout waiting for ARP/RARP packet Timeout waiting for ARP/RARP packet 4000 1000 Mbps FDX Link up Requesting Internet address for 0:3:ba:2f:c9:61 SunOS Release 5.10 Version Generic_118833-17 64-bit Copyright 1983-2005 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Booting to milestone "milestone/single-user:default". Configuring devices. Using RPC Bootparams for network configuration information. Attempting to configure interface bge0... Configured interface bge0 Requesting System Maintenance Mode SINGLE USER MODE # Our goal is to now move to the directory containing the buggy driver and replace it with the original driver (that we had saved away before ever loading our buggy driver! :-) However, since we booted from the network, the root filesystem ("/") is NOT mounted on one of our local disks. It is mounted on an NFS filesystem exported by our install server. To verify this, enter the following command: # mount | head -1 / on my-server:/export/install/media/s10u2/solarisdvd.s10s_u2dvd/latest/Solaris_10/Tools/Boot remote/read/write/setuid/devices/dev=4ac0001 on Wed Dec 31 16:00:00 1969 As a result, we have to create a temporary mount point and then mount the local disk onto that mount point: # mkdir /tmp/mnt # mount /dev/dsk/c0t0d0s0 /tmp/mnt Note that your system will not necessarily have had its root filesystem on "c0t0d0s0". This is something that you should also have recorded before you ever loaded your.. er... "my" buggy driver! :-) One can find the local disk mounted under the root filesystem by entering: # df -k / Filesystem kbytes used avail capacity Mounted on /dev/dsk/c0t0d0s0 76703839 4035535 71901266 6% / To continue with our example, we can now move to the directory of buggy-driver in order to replace it with the original driver. Note that /tmp/mnt is prefixed to the path of where we'd "normally" find the driver: # cd /tmp/mnt/platform/sun4u/kernel/drv/sparcv9 # ls -l pci\* -rw-r--r-- 1 root root 288504 Dec 6 15:38 pcisch -rw-r--r-- 1 root root 288504 Dec 6 15:38 pcisch.aar -rwxr-xr-x 1 root sys 211616 Jun 8 2006 pcisch.orig # cp -p pcisch.orig pcisch We can now synchronize any in-memory filesystem data structures with those on disk... and then reboot. The system will then boot correctly... as expected: # sync;sync # reboot syncing file systems... done Sun Blade 1500, No Keyboard Copyright 1998-2004 Sun Microsystems, Inc. All rights reserved. OpenBoot 4.16.4, 1024 MB memory installed, Serial #xxxxxxxx. Ethernet address 0:3:ba:2f:c9:61, Host ID: yyyyyyyy. Rebooting with command: boot Boot device: /pci@1e,600000/ide@d/disk@0,0:a File and args: SunOS Release 5.10 Version Generic_118833-17 64-bit Copyright 1983-2005 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Hostname: my-host NIS domain name is my-campus.Central.Sun.COM my-host console login: ...so that's how it's done! Of course, the easier way is to never write a buggy-driver... but.. then.. we all "have an eraser on the end of each of our pencils"... don't we ? :-) "...thank you... and good night..."

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  • How can I estimate the entropy of a password?

    - by Wug
    Having read various resources about password strength I'm trying to create an algorithm that will provide a rough estimation of how much entropy a password has. I'm trying to create an algorithm that's as comprehensive as possible. At this point I only have pseudocode, but the algorithm covers the following: password length repeated characters patterns (logical) different character spaces (LC, UC, Numeric, Special, Extended) dictionary attacks It does NOT cover the following, and SHOULD cover it WELL (though not perfectly): ordering (passwords can be strictly ordered by output of this algorithm) patterns (spatial) Can anyone provide some insight on what this algorithm might be weak to? Specifically, can anyone think of situations where feeding a password to the algorithm would OVERESTIMATE its strength? Underestimations are less of an issue. The algorithm: // the password to test password = ? length = length(password) // unique character counts from password (duplicates discarded) uqlca = number of unique lowercase alphabetic characters in password uquca = number of uppercase alphabetic characters uqd = number of unique digits uqsp = number of unique special characters (anything with a key on the keyboard) uqxc = number of unique special special characters (alt codes, extended-ascii stuff) // algorithm parameters, total sizes of alphabet spaces Nlca = total possible number of lowercase letters (26) Nuca = total uppercase letters (26) Nd = total digits (10) Nsp = total special characters (32 or something) Nxc = total extended ascii characters that dont fit into other categorys (idk, 50?) // algorithm parameters, pw strength growth rates as percentages (per character) flca = entropy growth factor for lowercase letters (.25 is probably a good value) fuca = EGF for uppercase letters (.4 is probably good) fd = EGF for digits (.4 is probably good) fsp = EGF for special chars (.5 is probably good) fxc = EGF for extended ascii chars (.75 is probably good) // repetition factors. few unique letters == low factor, many unique == high rflca = (1 - (1 - flca) ^ uqlca) rfuca = (1 - (1 - fuca) ^ uquca) rfd = (1 - (1 - fd ) ^ uqd ) rfsp = (1 - (1 - fsp ) ^ uqsp ) rfxc = (1 - (1 - fxc ) ^ uqxc ) // digit strengths strength = ( rflca * Nlca + rfuca * Nuca + rfd * Nd + rfsp * Nsp + rfxc * Nxc ) ^ length entropybits = log_base_2(strength) A few inputs and their desired and actual entropy_bits outputs: INPUT DESIRED ACTUAL aaa very pathetic 8.1 aaaaaaaaa pathetic 24.7 abcdefghi weak 31.2 H0ley$Mol3y_ strong 72.2 s^fU¬5ü;y34G< wtf 88.9 [a^36]* pathetic 97.2 [a^20]A[a^15]* strong 146.8 xkcd1** medium 79.3 xkcd2** wtf 160.5 * these 2 passwords use shortened notation, where [a^N] expands to N a's. ** xkcd1 = "Tr0ub4dor&3", xkcd2 = "correct horse battery staple" The algorithm does realize (correctly) that increasing the alphabet size (even by one digit) vastly strengthens long passwords, as shown by the difference in entropy_bits for the 6th and 7th passwords, which both consist of 36 a's, but the second's 21st a is capitalized. However, they do not account for the fact that having a password of 36 a's is not a good idea, it's easily broken with a weak password cracker (and anyone who watches you type it will see it) and the algorithm doesn't reflect that. It does, however, reflect the fact that xkcd1 is a weak password compared to xkcd2, despite having greater complexity density (is this even a thing?). How can I improve this algorithm? Addendum 1 Dictionary attacks and pattern based attacks seem to be the big thing, so I'll take a stab at addressing those. I could perform a comprehensive search through the password for words from a word list and replace words with tokens unique to the words they represent. Word-tokens would then be treated as characters and have their own weight system, and would add their own weights to the password. I'd need a few new algorithm parameters (I'll call them lw, Nw ~= 2^11, fw ~= .5, and rfw) and I'd factor the weight into the password as I would any of the other weights. This word search could be specially modified to match both lowercase and uppercase letters as well as common character substitutions, like that of E with 3. If I didn't add extra weight to such matched words, the algorithm would underestimate their strength by a bit or two per word, which is OK. Otherwise, a general rule would be, for each non-perfect character match, give the word a bonus bit. I could then perform simple pattern checks, such as searches for runs of repeated characters and derivative tests (take the difference between each character), which would identify patterns such as 'aaaaa' and '12345', and replace each detected pattern with a pattern token, unique to the pattern and length. The algorithmic parameters (specifically, entropy per pattern) could be generated on the fly based on the pattern. At this point, I'd take the length of the password. Each word token and pattern token would count as one character; each token would replace the characters they symbolically represented. I made up some sort of pattern notation, but it includes the pattern length l, the pattern order o, and the base element b. This information could be used to compute some arbitrary weight for each pattern. I'd do something better in actual code. Modified Example: Password: 1234kitty$$$$$herpderp Tokenized: 1 2 3 4 k i t t y $ $ $ $ $ h e r p d e r p Words Filtered: 1 2 3 4 @W5783 $ $ $ $ $ @W9001 @W9002 Patterns Filtered: @P[l=4,o=1,b='1'] @W5783 @P[l=5,o=0,b='$'] @W9001 @W9002 Breakdown: 3 small, unique words and 2 patterns Entropy: about 45 bits, as per modified algorithm Password: correcthorsebatterystaple Tokenized: c o r r e c t h o r s e b a t t e r y s t a p l e Words Filtered: @W6783 @W7923 @W1535 @W2285 Breakdown: 4 small, unique words and no patterns Entropy: 43 bits, as per modified algorithm The exact semantics of how entropy is calculated from patterns is up for discussion. I was thinking something like: entropy(b) * l * (o + 1) // o will be either zero or one The modified algorithm would find flaws with and reduce the strength of each password in the original table, with the exception of s^fU¬5ü;y34G<, which contains no words or patterns.

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  • Waiting for Windows 8: A Long, Hot Summer

    - by andrewbrust
    Microsoft has revealed some things about Windows 8, and revealed a part of the developer story for new Windows 8 “tailored,” “immersive” applications.  In retrospect, very little was shared.  The bit that was revealed to us is that those applications can be developed using a combination of HTML 5 and JavaScript.  Not much else was said, except that additional details would be revealed at Microsoft’s //Build/ conference in Anaheim, California in September. This has left a lot of people in suspense, and it seems that suspended state is going to last all summer.  The problem, of course, is that in the absence of hard information, people fill the void with Speculation, Rumor and Gloom.  That’s a bit like Fear, Uncertainty and Doubt, except that it’s self-imposed by the Microsoft community and not planted by Microsoft’s competitors. This is a less-than-perfect situation.  Not only is it causing developers to worry about the value of their skill sets, but I am already hearing from consulting shops that customers are getting nervous too and, in extreme cases, opting for non-Microsoft tools for their projects as a result.  I’m also hearing from dev tool ISVs that sales have suffered as a result. It’s quite possible that the customers moving off .NET wanted to do so anyway and it’s also possible that dev tool ISVs are suffering slower sales this year due a slowed rate of economic recovery. Without hard information, tend to people interpret things negatively.  Actually, that’s the major point in all of this. While there is multitude of opinions about what the Windows 8 development platform will look like once fully revealed, there is an emerging consensus around one thing: it sure would help if Microsoft revealed more of its strategy…just enough to quash absurd rumors, stabilize the .NET ecosystem and get people to stay calm. We’ve had some reassurances thus far: there will be a Windows desktop mode; we’ll still have Windows Explorer, we’ll still run Office, we’ll still have a task bar, and all the skills and tools we use now will still work there.  But with reassurances like that…people still feel insecure.  Because telling us that Windows 8 will have what is essentially a “classic” mode sure makes it sound like today’s skill sets will soon be “classic” too…and then maybe they’ll just become obsolete. Humans find change scary; it’s natural.  And when left alone with their fears – because no one is saying anything to dispel them – people can go from frightened to paranoid, and can start to viewing things in a downright conspiratorial light.  It would be great if Microsoft stepped into the void now and told us what is coming – especially because whatever they tell us is bound to be at least a little better than what people think they are going to hear. I don’t know what the announcements will be, but I do have it on authority, from a number of sources, that Microsoft isn’t gong to talk until //Build/.  That means no news until September September 13th.  Nothing until after Labor Day.  You get zippo until after the Back-to-School sales are done. What to do?  Try not to let the dark voices of gloom and doom fill your head.  Even in the absence of answers, we still have some important facts: The .NET developer community is huge. Microsoft’s customers have major investments in .NET, and in .NET skills. Political infighting in Redmond might make for irrational decisions, but ultimately public companies can’t just alienate their advocates and piss off their customers.  Spite doesn’t trump fiduciary responsibility. The computing device markets are changing, software is changing, software business models are changing and developers are changing.  Microsoft has to keep up. The HTML + JavaScript community is huge too, and it includes many of the “changed” developers. Public companies can’t ignore new markets nor the popular standards that can help them enter those new markets.  Loyalty doesn’t trump fiduciary responsibility either. If Microsoft can appeal to new developers, then it should. If Microsoft can keep catering to its existing developers and customers -- not just through legacy support, but also through empowering futures -- then it probably will. You don’t have to shove your old friends out into the rain to make room for new ones; you can bring those new constituents in under a bigger tent.  I hope Microsoft will enlarge the tent, and I have trouble imagining why it would not.

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  • University teaches DOS-style C++, how to deal with it

    - by gaidal
    Half a year ago I had a look at available programming educations. I chose this one because unlike most of the choices: The majority of the courses seemed to be about something concrete and useful; the languages used are C++ and Java which are platform-independent; later courses include developing for mobile devices and a course on Android development, which seemed modern and relevant. Now after two introductory courses we're just starting with C++, and my programming professor seems a bit weird. He's tested us on things like "why should you use constants" and "why are globals bad" in a kind of mechanical way, without much context, before teaching actual programming. His handouts use system("pause"), system("cls"), and getch() from some conio.h that seems ancient according to what I've read. I just did a task that was about printing the "ASCII letters from 32 to 255" (huh?), with an example picture showing a table with Windows' Extended ASCII - of course I got other results for 128-255 on my Arch Linux that uses Unicode, and this isn't mentioned at all. I don't know, it just doesn't seem right... As if he is teaching programming because he has to, perhaps? Should I bring such things up? Hmm. I was looking forward to learning from someone who really knows stuff, and in an academic, rigorous way, like SICP or something. Aren't professors in programming supposed to be like that? I studied math for a while and every teacher and assistant there were really precise about what they said, but this is my second programming teacher that is sort of disappointing. Oh well. Now, question: Is this what to expect from universities or Not OK, and how do I deal with it? I have never touched the language C++ (or C) until now, and am not the right person to jump up and say "This is So Wrong!", so if I google something and find 10 people who say "xxx is blasphemy", how do I skillfully communicate this? I do think it would be better for those classmates who are total beginners not to learn bad habits (such as these vibes of total ignorance of other platforms!) during the upcoming courses, but don't want to disrespect the teacher. I don't know if it's reasonable or just cocky to bring up things like "what about other platforms?" or "but what about this article or stackoverflow answer that I read that said..." for every assignment? Or, if he keeps ignoring non-Windows-programming, should I give up and focus on my own projects or somehow argue that this really isn't OK nowadays? Are there any programming teachers out there, what do you think? By the way these are web-based courses, all interaction between teachers and students takes place in a forum. EDIT: A few answers seem to be making some incorrect assumptions, so maybe I should add a few things. I have been doing programming for fun on and off for 10 years, am pretty comfortable in 3 languages and read programming blogs et c regularly. Also, I feel kind of done being a student, having a degree in another field. I just need another, relevant diploma to work as a programmer, so I'm going back for that. Studying computer science for 5 years is not for me anymore, even though I enjoy learning and solving problems in my free time. Second, let me highlight that I don't expect it to be like the industry at all, quite the contrary. I expect it to be academic, dry and unnecessarily correct. No, it's not just math. Every professor I have had in math, or Japanese (major) or Chinese (minor) have been very very academic, discussing subtle points for hours with passion. But the courses I'm taking now and a previous one in programming don't seem serious. They neither resemble industry NOR academia. That is the problem. And it's not because I can't learn programming anyway. Third, I don't necessarily want to learn C++ or Android development, and I know I could teach myself those and anything else if I wanted to. But I am going back to school anyway, and those platform-independent languages and mobile stuff made me think that maybe they're serious about teaching something relevant here. Seems like I got this wrong, but we'll see.

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  • Windows 8 for productivity?

    - by Charles Young
    At long last I’ve started using Windows 8.  I boot from a VHD on which I have installed Office, Visio, Visual Studio, SQL Server, etc.  For a week, now, I’ve been happily writing code and documents and using Visio and PowerPoint.  I am, very much, a ‘productivity’ user rather than a content consumer.   I spend my days flitting between countless windows and browser tabs displayed across dual monitors.  I need to access a lot of different functionality and information in as fluid a fashion as possible. With that in mind, and like so many others, I was worried about Windows 8.  The Metro interface is primarily about content consumption on touch-enabled screens, and not really geared for people like me sitting in front of an 8-core non-touch laptop and an additional Samsung monitor.  I still use a mouse, not my finger.  And I create more than I consume. Clearly, Windows 8 won’t be viable for people like me unless Metro keeps out of my hair when using productivity and development tools.  With this in mind, I had long expected Microsoft to provide some mechanism for switching Metro off.  There was a registry hack in last year’s Developer Preview, but this capability has been removed.   That’s brave.  So, how have things worked out so far? Well, I am really quite surprised.  When I played with the Developer Preview last year, it was clear that Metro was unfinished and didn’t play well enough with the desktop.  Obviously I expected things to improve, but the context switching from desktop to full-screen seemed a heavy burden to place on users.  That sense of abrupt change hasn’t entirely gone away (how could it), but after a few days, I can’t say that I find it burdensome or irritating.   I’ve got used very quickly to ‘gesturing’ with my mouse at the bottom or top right corners of the screen to move between applications, using the Windows key to toggle the Start screen and generally finding my way around.   I am surprised at how effective the Start screen is, given the rather basic grouping features it provides.  Of course, I had to take control of it and sort things the way I want.  If anything, though, the Start screen provides a better navigation and application launcher tool than the old Start menu. What I didn’t expect was the way that Metro enhances the productivity story.  As I write this, I’ve got my desktop open with a maximised Word window.  However, the desktop extends only across about 85% of the width of my screen.  On the left hand side, I have a column that displays the new Metro email client.  This is currently showing me a list of emails for my main work account.  I can flip easily between different accounts and read my email within that same column.  As I work on documents, I want to be able to monitor my inbox with a quick glance. The desktop, of course, has its own snap feature.  I could run the desktop full screen and bring up Outlook and Word side by side.  However, this doesn’t begin to approach the convenience of snapping the Metro email client.  Consider that when I snap a window on the desktop, it initially takes up 50% of the screen.  Outlook doesn’t really know anything about snap, and doesn’t adjust to make effective use of the limited screen estate.  Even at 50% screen width, it is difficult to use, so forget about trying to use it in a Metro fashion. In any case, I am left with the prospect of having to manually adjust everything to view my email effectively alongside Word.  Worse, there is nothing stopping another window from overlapping and obscuring my email.  It becomes a struggle to keep sight of email as it arrives.  Of course, there is always ‘toast’ to notify me when things arrive, but if Outlook is obscured, this just feels intrusive. The beauty of the Metro snap feature is that my email reader now exists outside of my desktop.   The Metro app has been crafted to work well in the fixed width column as well as in full-screen.  It cannot be obscured by overlapping windows.  I still get notifications if I wish.  More importantly, it is clear that careful attention has been given to how things work when moving between applications when ‘snapped’.  If I decide, say to flick over to the Metro newsreader to catch up with current affairs, my desktop, rather than my email client, obligingly makes way for the reader.  With a simple gesture and click, or alternatively by pressing Windows-Tab, my desktop reappears. Another pleasant surprise is the way Windows 8 handles dual monitors.  It’s not just the fact that both screens now display the desktop task bar.  It’s that I can so easily move between Metro and the desktop on either screen.  I can only have Metro on one screen at a time which makes entire sense given the ‘full-screen’ nature of Metro apps.  Using dual monitors feels smoother and easier than previous versions of Windows. Overall then, I’m enjoying the Windows 8 improvements.  Strangely, for all the hype (“Windows reimagined”, etc.), my perception as a ‘productivity’ user is more one of evolution than revolution.  It all feels very familiar, but just better.

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  • 2012&ndash;The End Of The World Review

    - by Tim Murphy
    The end of the world must be coming.  Not because the Mayan calendar says so, but because Microsoft is innovating more than Apple.  It has been a crazy year, with pundits declaring not that the end of the world is coming, but that the end of Microsoft is coming.  Let’s take a look at what 2012 has brought us. The beginning of year is a blur.  I managed to get to TechEd in June which was the first time that I got to take a deep dive into Windows 8 and many other things that had been announced in 2011.  The promise I saw in these products was really encouraging.  The thought of being able to run Windows 8 from a thumb drive or have Hyper-V native to the OS told me that at least for developers good things were coming. I finally got my feet wet with Windows 8 with the developer preview just prior to the RTM.  While the initial experience was a bit of a culture shock I quickly grew to love it.  The media still seems to hold little love for the “reimagined” platform, but I think that once people spend some time with it they will enjoy the experience and what the FUD mongers say will fade into the background.  With the launch of the OS we finally got a look at the Surface.  I think this is a bold entry into the tablet market.  While I wish it was a little more affordable I am already starting to see them in the wild being used by non-techies. I was waiting for Windows Phone 8 at least as much as Windows 8, probably more.  The new hardware, better marketing and new OS features I think are going to finally push us to the point of having a real presence in the smartphone market.  I am seeing a number of iPhone users picking up a Nokia Lumia 920 and getting rid of their brand new iPhone 5.  The only real debacle that I saw around the launch was when they held back the SDK from general developers. Shortly after the launch events came Build 2012.  I was extremely disappointed that I didn’t make it to this year’s Build.  Even if they weren’t handing out Surface and Lumia devices I think the atmosphere and content were something that really needed to be experience in person.  Hopefully there will be a Build next year and it’s schedule will be announced soon.  As you would expect Windows 8 and Windows Phone 8 development were the mainstay of the conference, but improvements in Azure also played a key role.  This movement of services to the cloud will continue and we need to understand where it best fits into the solutions we build. Lower on the radar this year were Office 2013, SQL Server 2012, and Windows Server 2012.  Their glory stolen by the consumer OS and hardware announcements, these new releases are no less important.  Companies will see significant improvements in performance and capabilities if they upgrade.  At TechEd they had shown some of the new features of Windows Server 2012 around hardware integration and Hyper-V performance which absolutely blew me away.  It is our job to bring these important improvements to our company’s attention so that they can be leveraged. Personally, the consulting business in 2012 was the busiest it has been in a long time.  More companies were ready to attack new projects after several years of putting them on the back burner.  I also worked to bring back momentum to the Chicago Information Technology Architects Group.  Both the community and clients are excited about the new technologies that have come out in 2012 and now it is time to deliver. What does 2013 have in store.  I don’t see it be quite as exciting as 2012.  Microsoft will be releasing the Surface Pro in January and it seems that we will see more frequent OS update for Windows.  There are rumors that we may see a Surface phone in 2013.  It has also been announced that there will finally be a rework of the XBox next fall.  The new year will also be a time for us in the development community to take advantage of these new tools and devices.  After all, it is what we build on top of these platforms that will attract more consumers and corporations to using them. Just as I am 99.999% sure that the world is not going to end this year, I am also sure that Microsoft will move on and that most of this negative backlash from the media is actually fear and jealousy.  In the end I think we have a promising year ahead of us. del.icio.us Tags: Microsoft,Pundits,Mayans,Windows 8,Windows Phone 8,Surface

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  • Solaris 11.1 changes building of code past the point of __NORETURN

    - by alanc
    While Solaris 11.1 was under development, we started seeing some errors in the builds of the upstream X.Org git master sources, such as: "Display.c", line 65: Function has no return statement : x_io_error_handler "hostx.c", line 341: Function has no return statement : x_io_error_handler from functions that were defined to match a specific callback definition that declared them as returning an int if they did return, but these were calling exit() instead of returning so hadn't listed a return value. These had been generating warnings for years which we'd been ignoring, but X.Org has made enough progress in cleaning up code for compiler warnings and static analysis issues lately, that the community turned up the default error levels, including the gcc flag -Werror=return-type and the equivalent Solaris Studio cc flags -v -errwarn=E_FUNC_HAS_NO_RETURN_STMT, so now these became errors that stopped the build. Yet on Solaris, gcc built this code fine, while Studio errored out. Investigation showed this was due to the Solaris headers, which during Solaris 10 development added a number of annotations to the headers when gcc was being used for the amd64 kernel bringup before the Studio amd64 port was ready. Since Studio did not support the inline form of these annotations at the time, but instead used #pragma for them, the definitions were only present for gcc. To resolve this, I fixed both sides of the problem, so that it would work for building new X.Org sources on older Solaris releases or with older Studio compilers, as well as fixing the general problem before it broke more software building on Solaris. To the X.Org sources, I added the traditional Studio #pragma does_not_return to recognize that functions like exit() don't ever return, in patches such as this Xserver patch. Adding a dummy return statement was ruled out as that introduced unreachable code errors from compilers and analyzers that correctly realized you couldn't reach that code after a return statement. And on the Solaris 11.1 side, I updated the annotation definitions in <sys/ccompile.h> to enable for Studio 12.0 and later compilers the annotations already existing in a number of system headers for functions like exit() and abort(). If you look in that file you'll see the annotations we currently use, though the forms there haven't gone through review to become a Committed interface, so may change in the future. Actually getting this integrated into Solaris though took a bit more work than just editing one header file. Our ELF binary build comparison tool, wsdiff, actually showed a large number of differences in the resulting binaries due to the compiler using this information for branch prediction, code path analysis, and other possible optimizations, so after comparing enough of the disassembly output to be comfortable with the changes, we also made sure to get this in early enough in the release cycle so that it would get plenty of test exposure before the release. It also required updating quite a bit of code to avoid introducing new lint or compiler warnings or errors, and people building applications on top of Solaris 11.1 and later may need to make similar changes if they want to keep their build logs similarly clean. Previously, if you had a function that was declared with a non-void return type, lint and cc would warn if you didn't return a value, even if you called a function like exit() or panic() that ended execution. For instance: #include <stdlib.h> int callback(int status) { if (status == 0) return status; exit(status); } would previously require a never executed return 0; after the exit() to avoid lint warning "function falls off bottom without returning value". Now the compiler & lint will both issue "statement not reached" warnings for a return 0; after the final exit(), allowing (or in some cases, requiring) it to be removed. However, if there is no return statement anywhere in the function, lint will warn that you've declared a function returning a value that never does so, suggesting you can declare it as void. Unfortunately, if your function signature is required to match a certain form, such as in a callback, you not be able to do so, and will need to add a /* LINTED */ to the end of the function. If you need your code to build on both a newer and an older release, then you will either need to #ifdef these unreachable statements, or, to keep your sources common across releases, add to your sources the corresponding #pragma recognized by both current and older compiler versions, such as: #pragma does_not_return(exit) #pragma does_not_return(panic) Hopefully this little extra work is paid for by the compilers & code analyzers being able to better understand your code paths, giving you better optimizations and more accurate errors & warning messages.

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