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• Agile Development Requires Agile Support

  - by Matt Watson

  Agile developmentAgile development has become the standard methodology for application development. The days of long term planning with giant Gantt waterfall charts and detailed requirements is fading away. For years the product planning process frustrated product owners and businesses because no matter the plan, nothing ever went to plan. Agile development throws the detailed planning out the window and instead focuses on giving developers some basic requirements and pointing them in the right direction. Constant collaboration via quick iterations with the end users, product owners, and the development team helps ensure the project is done correctly.  The various agile development methodologies have helped greatly with creating products faster, but not without causing new problems. Complicated application deployments now occur weekly or monthly. Most of the products are web-based and deployed as a software service model. System performance and availability of these apps becomes mission critical. This is all much different from the old process of mailing new releases of client-server apps on CD once per quarter or year.The steady stream of new products and product enhancements puts a lot of pressure on IT operations to keep up with the software deployments and adding infrastructure capacity. The problem is most operations teams still move slowly thanks to change orders, documentation, procedures, testing and other processes. Operations can slow the process down and push back on the development team in some organizations. The DevOps movement is trying to solve some of these problems by integrating the development and operations teams more together. Rapid change introduces new problemsThe rapid product change ultimately creates some application problems along the way. Higher rates of change increase the likelihood of new application defects. Delivering applications as a software service also means that scalability of applications is critical. Development teams struggle to keep up with application defects and scalability concerns in their applications. Fixing application problems is a never ending job for agile development teams. Fixing problems before your customers do and fixing them quickly is critical. Most companies really struggle with this due to the divide between the development and operations groups. Fixing application problems typically requires querying databases, looking at log files, reviewing config files, reviewing error logs and other similar tasks. It becomes difficult to work on new features when your lead developers are working on defects from the last product version. Developers need more visibilityThe problem is most developers are not given access to see server and application information in the production environments. The operations team doesn’t trust giving all the developers the keys to the kingdom to log in to production and poke around the servers. The challenge is either give them no access, or potentially too much access. Those with access can still waste time figuring out the location of the application and how to connect to it over VPN. In addition, reproducing problems in test environments takes too much time and isn't always possible. System administrators spend a lot of time helping developers track down server information. Most companies give key developers access to all of the production resources so they can help resolve application defects. The problem is only those key people have access and they become a bottleneck. They end up spending 25-50% of their time on a daily basis trying to solve application issues because they are the only ones with access. These key employees’ time is best spent on strategic new projects, not addressing application defects. This job should fall to entry level developers, provided they have access to all the information they need to troubleshoot the problems.The solution to agile application support is giving all the developers limited access to the production environment and all the server information they need to see. Some companies create their own solutions internally to collect log files, centralize errors or other things to address the problem. Some developers even have access to server monitoring or other tools. But they key is giving them access to everything they need so they can see the full picture and giving access to the whole team. Giving access to everyone scales up the application support team and creates collaboration around providing improved application support.Stackify enables agile application supportStackify has created a solution that can give all developers a secure and read only view of the entire production server environment without console or remote desktop access.They provide a web application that provides real time visibility to the important information that developers need to see. An application centric view enables them to see all of their apps across multiple datacenters and environments. They don’t need to know where the application is deployed, just the name of the application to find it and dig in to see more. All your developers can see server health, application health, log files, config files, windows event viewer, deployment history, application notes, and much more. They can receive email and text alerts when problems arise and even safely query your production databases.Stackify enables companies that do agile development to scale up their application support team by getting more team members involved. The lead developers can spend more time on new projects. Application issues can be fixed quicker than ever. Operations can spend less time helping developers collect server information. Agile application support starts with Stackify. Visit Stackify.com to learn more.

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• Subterranean IL: Generics and array covariance

  - by Simon Cooper

  Arrays in .NET are curious beasts. They are the only built-in collection types in the CLR, and SZ-arrays (single dimension, zero-indexed) have their own commands and IL syntax. One of their stranger properties is they have a kind of built-in covariance long before generic variance was added in .NET 4. However, this causes a subtle but important problem with generics. First of all, we need to briefly recap on array covariance. SZ-array covariance To demonstrate, I'll tweak the classes I introduced in my previous posts: public class IncrementableClass { public int Value; public virtual void Increment(int incrementBy) { Value += incrementBy; } } public class IncrementableClassx2 : IncrementableClass { public override void Increment(int incrementBy) { base.Increment(incrementBy); base.Increment(incrementBy); } } In the CLR, SZ-arrays of reference types are implicitly convertible to arrays of the element's supertypes, all the way up to object (note that this does not apply to value types). That is, an instance of IncrementableClassx2[] can be used wherever a IncrementableClass[] or object[] is required. When an SZ-array could be used in this fashion, a run-time type check is performed when you try to insert an object into the array to make sure you're not trying to insert an instance of IncrementableClass into an IncrementableClassx2[]. This check means that the following code will compile fine but will fail at run-time: IncrementableClass[] array = new IncrementableClassx2[1]; array[0] = new IncrementableClass(); // throws ArrayTypeMismatchException These checks are enforced by the various stelem* and ldelem* il instructions in such a way as to ensure you can't insert a IncrementableClass into a IncrementableClassx2[]. For the rest of this post, however, I'm going to concentrate on the ldelema instruction. ldelema This instruction pops the array index (int32) and array reference (O) off the stack, and pushes a pointer (&) to the corresponding array element. However, unlike the ldelem instruction, the instruction's type argument must match the run-time array type exactly. This is because, once you've got a managed pointer, you can use that pointer to both load and store values in that array element using the ldind* and stind* (load/store indirect) instructions. As the same pointer can be used for both input and output to the array, the type argument to ldelema must be invariant. At the time, this was a perfectly reasonable restriction, and maintained array type-safety within managed code. However, along came generics, and with it the constrained callvirt instruction. So, what happens when we combine array covariance and constrained callvirt? .method public static void CallIncrementArrayValue() { // IncrementableClassx2[] arr = new IncrementableClassx2[1] ldc.i4.1 newarr IncrementableClassx2 // arr[0] = new IncrementableClassx2(); dup newobj instance void IncrementableClassx2::.ctor() ldc.i4.0 stelem.ref // IncrementArrayValue<IncrementableClass>(arr, 0) // here, we're treating an IncrementableClassx2[] as IncrementableClass[] dup ldc.i4.0 call void IncrementArrayValue<class IncrementableClass>(!!0[],int32) // ... ret } .method public static void IncrementArrayValue<(IncrementableClass) T>( !!T[] arr, int32 index) { // arr[index].Increment(1) ldarg.0 ldarg.1 ldelema !!T ldc.i4.1 constrained. !!T callvirt instance void IIncrementable::Increment(int32) ret } And the result: Unhandled Exception: System.ArrayTypeMismatchException: Attempted to access an element as a type incompatible with the array. at IncrementArrayValue[T](T[] arr, Int32 index) at CallIncrementArrayValue() Hmm. We're instantiating the generic method as IncrementArrayValue<IncrementableClass>, but passing in an IncrementableClassx2[], hence the ldelema instruction is failing as it's expecting an IncrementableClass[]. On features and feature conflicts What we've got here is a conflict between existing behaviour (ldelema ensuring type safety on covariant arrays) and new behaviour (managed pointers to object references used for every constrained callvirt on generic type instances). And, although this is an edge case, there is no general workaround. The generic method could be hidden behind several layers of assemblies, wrappers and interfaces that make it a requirement to use array covariance when calling the generic method. Furthermore, this will only fail at runtime, whereas compile-time safety is what generics were designed for! The solution is the readonly. prefix instruction. This modifies the ldelema instruction to ignore the exact type check for arrays of reference types, and so it lets us take the address of array elements using a covariant type to the actual run-time type of the array: .method public static void IncrementArrayValue<(IncrementableClass) T>( !!T[] arr, int32 index) { // arr[index].Increment(1) ldarg.0 ldarg.1 readonly. ldelema !!T ldc.i4.1 constrained. !!T callvirt instance void IIncrementable::Increment(int32) ret } But what about type safety? In return for ignoring the type check, the resulting controlled mutability pointer can only be used in the following situations: As the object parameter to ldfld, ldflda, stfld, call and constrained callvirt instructions As the pointer parameter to ldobj or ldind* As the source parameter to cpobj In other words, the only operations allowed are those that read from the pointer; stind* and similar that alter the pointer itself are banned. This ensures that the array element we're pointing to won't be changed to anything untoward, and so type safety within the array is maintained. This is a typical example of the maxim that whenever you add a feature to a program, you have to consider how that feature interacts with every single one of the existing features. Although an edge case, the readonly. prefix instruction ensures that generics and array covariance work together and that compile-time type safety is maintained. Tune in next time for a look at the .ctor generic type constraint, and what it means.

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• .NET Security Part 4

  - by Simon Cooper

  Finally, in this series, I am going to cover some of the security issues that can trip you up when using sandboxed appdomains. DISCLAIMER: I am not a security expert, and this is by no means an exhaustive list. If you actually are writing security-critical code, then get a proper security audit of your code by a professional. The examples below are just illustrations of the sort of things that can go wrong. 1. AppDomainSetup.ApplicationBase The most obvious one is the issue covered in the MSDN documentation on creating a sandbox, in step 3 – the sandboxed appdomain has the same ApplicationBase as the controlling appdomain. So let’s explore what happens when they are the same, and an exception is thrown. In the sandboxed assembly, Sandboxed.dll (IPlugin is an interface in a partially-trusted assembly, with a single MethodToDoThings on it): public class UntrustedPlugin : MarshalByRefObject, IPlugin { // implements IPlugin.MethodToDoThings() public void MethodToDoThings() { throw new EvilException(); } } [Serializable] internal class EvilException : Exception { public override string ToString() { // show we have read access to C:\Windows // read the first 5 directories Console.WriteLine("Pwned! Mwuahahah!"); foreach (var d in Directory.EnumerateDirectories(@"C:\Windows").Take(5)) { Console.WriteLine(d.FullName); } return base.ToString(); } } And in the controlling assembly: // what can possibly go wrong? AppDomainSetup appDomainSetup = new AppDomainSetup { ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase } // only grant permissions to execute // and to read the application base, nothing else PermissionSet restrictedPerms = new PermissionSet(PermissionState.None); restrictedPerms.AddPermission( new SecurityPermission(SecurityPermissionFlag.Execution)); restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.Read, appDomainSetup.ApplicationBase); restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.pathDiscovery, appDomainSetup.ApplicationBase); // create the sandbox AppDomain sandbox = AppDomain.CreateDomain("Sandbox", null, appDomainSetup, restrictedPerms); // execute UntrustedPlugin in the sandbox // don't crash the application if the sandbox throws an exception IPlugin o = (IPlugin)sandbox.CreateInstanceFromAndUnwrap("Sandboxed.dll", "UntrustedPlugin"); try { o.MethodToDoThings() } catch (Exception e) { Console.WriteLine(e.ToString()); } And the result? Oops. We’ve allowed a class that should be sandboxed to execute code with fully-trusted permissions! How did this happen? Well, the key is the exact meaning of the ApplicationBase property: The application base directory is where the assembly manager begins probing for assemblies. When EvilException is thrown, it propagates from the sandboxed appdomain into the controlling assembly’s appdomain (as it’s marked as Serializable). When the exception is deserialized, the CLR finds and loads the sandboxed dll into the fully-trusted appdomain. Since the controlling appdomain’s ApplicationBase directory contains the sandboxed assembly, the CLR finds and loads the assembly into a full-trust appdomain, and the evil code is executed. So the problem isn’t exactly that the sandboxed appdomain’s ApplicationBase is the same as the controlling appdomain’s, it’s that the sandboxed dll was in such a place that the controlling appdomain could find it as part of the standard assembly resolution mechanism. The sandbox then forced the assembly to load in the controlling appdomain by throwing a serializable exception that propagated outside the sandbox. The easiest fix for this is to keep the sandbox ApplicationBase well away from the ApplicationBase of the controlling appdomain, and don’t allow the sandbox permissions to access the controlling appdomain’s ApplicationBase directory. If you do this, then the sandboxed assembly can’t be accidentally loaded into the fully-trusted appdomain, and the code can’t be executed. If the plugin does try to induce the controlling appdomain to load an assembly it shouldn’t, a SerializationException will be thrown when it tries to load the assembly to deserialize the exception, and no damage will be done. 2. Loading the sandboxed dll into the application appdomain As an extension of the previous point, you shouldn’t directly reference types or methods in the sandboxed dll from your application code. That loads the assembly into the fully-trusted appdomain, and from there code in the assembly could be executed. Instead, pull out methods you want the sandboxed dll to have into an interface or class in a partially-trusted assembly you control, and execute methods via that instead (similar to the example above with the IPlugin interface). If you need to have a look at the assembly before executing it in the sandbox, either examine the assembly using reflection from within the sandbox, or load the assembly into the Reflection-only context in the application’s appdomain. The code in assemblies in the reflection-only context can’t be executed, it can only be reflected upon, thus protecting your appdomain from malicious code. 3. Incorrectly asserting permissions You should only assert permissions when you are absolutely sure they’re safe. For example, this method allows a caller read-access to any file they call this method with, including your documents, any network shares, the C:\Windows directory, etc: [SecuritySafeCritical] public static string GetFileText(string filePath) { new FileIOPermission(FileIOPermissionAccess.Read, filePath).Assert(); return File.ReadAllText(filePath); } Be careful when asserting permissions, and ensure you’re not providing a loophole sandboxed dlls can use to gain access to things they shouldn’t be able to. Conclusion Hopefully, that’s given you an idea of some of the ways it’s possible to get past the .NET security system. As I said before, this post is not exhaustive, and you certainly shouldn’t base any security-critical applications on the contents of this blog post. What this series should help with is understanding the possibilities of the security system, and what all the security attributes and classes mean and what they are used for, if you were to use the security system in the future.

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• Modularity through HTTP

  - by Michael Williamson

  As programmers, we strive for modularity in the code we write. We hope that splitting the problem up makes it easier to solve, and allows us to reuse parts of our code in other applications. Object-orientation is the most obvious of many attempts to get us closer to this ideal, and yet one of the most successful approaches is almost accidental: the web. Programming languages provide us with functions and classes, and plenty of other ways to modularize our code. This allows us to take our large problem, split it into small parts, and solve those small parts without having to worry about the whole. It also makes it easier to reason about our code. So far, so good, but now that we’ve written our small, independent module, for example to send out e-mails to my customers, we’d like to reuse it in another application. By creating DLLs, JARs or our platform’s package container of choice, we can do just that – provided our new application is on the same platform. Want to use a Java library from C#? Well, good luck – it might be possible, but it’s not going to be smooth sailing. Even if a library exists, it doesn’t mean that using it going to be a pleasant experience. Say I want to use Java to write out an XML document to an output stream. You’d imagine this would be a simple one-liner. You’d be wrong: import org.w3c.dom.*; import java.io.*; import javax.xml.transform.*; import javax.xml.transform.dom.*; import javax.xml.transform.stream.*; private static final void writeDoc(Document doc, OutputStream out) throws IOException { try { Transformer t = TransformerFactory.newInstance().newTransformer(); t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId()); t.transform(new DOMSource(doc), new StreamResult(out)); } catch (TransformerException e) { throw new AssertionError(e); // Can't happen! } } Most of the time, there is a good chance somebody else has written the code before, but if nobody can understand the interface to that code, nobody’s going to use it. The result is that most of the code we write is just a variation on a theme. Despite our best efforts, we’ve fallen a little short of our ideal, but the web brings us closer. If we want to send e-mails to our customers, we could write an e-mail-sending library. More likely, we’d use an existing one for our language. Even then, we probably wouldn’t have niceties like A/B testing or DKIM signing. Alternatively, we could just fire some HTTP requests at MailChimp, and get a whole slew of features without getting anywhere near the code that implements them. The web is inherently language agnostic. So long as your language can send and receive text over HTTP, and probably parse some JSON, you’re about as well equipped as anybody. Instead of building libraries for a specific language, we can build a service that almost every language can reuse. The text-based nature of HTTP also helps to limit the complexity of the API. As SOAP will attest, you can still make a horrible mess using HTTP, but at least it is an obvious horrible mess. Complex data structures are tedious to marshal to and from text, providing a strong incentive to keep things simple. By contrast, spotting the complexities in a class hierarchy is often not as easy. HTTP doesn’t solve every problem. It probably isn’t such a good idea to use it inside an inner loop that’s executed thousands of times per second. What’s more, the HTTP approach might introduce some new problems. We often need to add a thin shim to each application that we wish to communicate over HTTP. For instance, we might need to write a small plugin in PHP if we want to integrate WordPress into our system. Suddenly, instead of a system written in one language, we’re maintaining a system with several distinct languages and platforms. Even then, we should strive to avoid re-implementing the same old thing. As programmers, we consistently underestimate both the cost of building a system and the ongoing maintenance. If we allow ourselves to integrate existing applications, even if they’re in unfamiliar languages, we save ourselves those development and maintenance costs, as well as being able to pick the best solution for our problem. Thanks to the web, HTTP is often the easiest way to get there.

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• Get coordinates of arraylist

  - by opiop65

  Here's my map class: public class map{ public static final int CLEAR = 0; public static final ArrayList<Integer> STONE = new ArrayList<Integer>(); public static final int GRASS = 2; public static final int DIRT = 3; public static final int WIDTH = 32; public static final int HEIGHT = 24; public static final int TILE_SIZE = 25; // static int[][] map = new int[WIDTH][HEIGHT]; ArrayList<ArrayList<Integer>> map = new ArrayList<ArrayList<Integer>>(WIDTH * HEIGHT); enum tiles { air, grass, stone, dirt } Image air, grass, stone, dirt; Random rand = new Random(); public Map() { /* default map */ /*for(int y = 0; y < WIDTH; y++){ map[y][y] = (rand.nextInt(2)); System.out.println(map[y][y]); }*/ /*for (int y = 18; y < HEIGHT; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = STONE; } } for (int y = 18; y < 19; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = GRASS; } } for (int y = 19; y < 20; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = DIRT; } }*/ for (int y = 0; y < HEIGHT; y++) { for(int x = 0; x < WIDTH; x++){ map.set(x * WIDTH + y, STONE); } } try { init(null, null); } catch (SlickException e) { e.printStackTrace(); } render(null, null, null); } public void init(GameContainer gc, StateBasedGame sbg) throws SlickException { air = new Image("res/air.png"); grass = new Image("res/grass.png"); stone = new Image("res/stone.png"); dirt = new Image("res/dirt.png"); } public void render(GameContainer gc, StateBasedGame sbg, Graphics g) { for (int x = 0; x < WIDTH; x++) { for (int y = 0; y < HEIGHT; y++) { switch (map.get(x * WIDTH + y)) { case CLEAR: air.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case STONE: stone.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case GRASS: grass.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case DIRT: dirt.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; } } } } public static boolean blocked(float x, float y) { return map[(int) x][(int) y] == STONE; } public static Rectangle blockBounds(int x, int y) { return (new Rectangle(x, y, TILE_SIZE, TILE_SIZE)); } } Specifically I am looking at this: for (int x = 0; x < WIDTH; x++) { for (int y = 0; y < HEIGHT; y++) { switch (map.get(x * WIDTH + y).intValue()) { case CLEAR: air.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case STONE: stone.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case GRASS: grass.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case DIRT: dirt.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; } } } How can I access the coordinates of my arraylist map and then draw the tiles to the screen? Thanks!

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• Thread.Interrupt Is Evil

  - by Alois Kraus

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

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• Getting Started with Amazon Web Services in NetBeans IDE

  - by Geertjan

  When you need to connect to Amazon Web Services, NetBeans IDE gives you a nice start. You can drag and drop the "itemSearch" service into a Java source file and then various Amazon files are generated for you. From there, you need to do a little bit of work because the request to Amazon needs to be signed before it can be used. Here are some references and places that got me started: http://associates-amazon.s3.amazonaws.com/signed-requests/helper/index.html http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSGettingStartedGuide/AWSCredentials.html https://affiliate-program.amazon.com/gp/flex/advertising/api/sign-in.html You definitely need to sign up to the Amazon Associates program and also register/create an Access Key ID, which will also get you a Secret Key, as well. Here's a simple Main class that I created that hooks into the generated RestConnection/RestResponse code created by NetBeans IDE: public static void main(String[] args) {    try {        String searchIndex = "Books";        String keywords = "Romeo and Juliet";        RestResponse result = AmazonAssociatesService.itemSearch(searchIndex, keywords);        String dataAsString = result.getDataAsString();        int start = dataAsString.indexOf("<Author>")+8;        int end = dataAsString.indexOf("</Author>");        System.out.println(dataAsString.substring(start,end));    } catch (Exception ex) {        ex.printStackTrace();    }} Then I deleted the generated properties file and the authenticator and changed the generated AmazonAssociatesService.java file to the following: public class AmazonAssociatesService {    private static void sleep(long millis) {        try {            Thread.sleep(millis);        } catch (Throwable th) {        }    }    public static RestResponse itemSearch(String searchIndex, String keywords) throws IOException {        SignedRequestsHelper helper;        RestConnection conn = null;        Map queryMap = new HashMap();        queryMap.put("Service", "AWSECommerceService");        queryMap.put("AssociateTag", "myAssociateTag");        queryMap.put("AWSAccessKeyId", "myAccessKeyId");        queryMap.put("Operation", "ItemSearch");        queryMap.put("SearchIndex", searchIndex);        queryMap.put("Keywords", keywords);        try {            helper = SignedRequestsHelper.getInstance(                    "ecs.amazonaws.com",                    "myAccessKeyId",                    "mySecretKey");            String sign = helper.sign(queryMap);            conn = new RestConnection(sign);        } catch (IllegalArgumentException | UnsupportedEncodingException | NoSuchAlgorithmException | InvalidKeyException ex) {        }        sleep(1000);        return conn.get(null);    }} Finally, I copied this class into my application, which you can see is referred to above: http://code.google.com/p/amazon-product-advertising-api-sample/source/browse/src/com/amazon/advertising/api/sample/SignedRequestsHelper.java Here's the completed app, mostly generated via the drag/drop shown at the start, but slightly edited as shown above: That's all, now everything works as you'd expect.

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• Data Binding to Attached Properties

  - by Chris Gardner

  Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2013/06/14/data-binding-to-attached-properties.aspx When I was working on my C#/XAML game framework, I discovered I wanted to try to data bind my sprites to background objects. That way, I could update my objects and the draw functionality would take care of the work for me. After a little experimenting and web searching, it appeared this concept was an impossible dream. Of course, when has that ever stopped me? In my typical way, I started to massively dive down the rabbit hole. I created a sprite on a canvas, and I bound it to a background object. <Canvas Name="GameField" Background="Black"> <Image Name="PlayerStrite" Source="Assets/Ship.png" Width="50" Height="50" Canvas.Left="{Binding X}" Canvas.Top="{Binding Y}"/> </Canvas> Now, we wire the UI item to the background item. public MainPage() { this.InitializeComponent(); this.Loaded += StartGame; }   void StartGame( object sender, RoutedEventArgs e ) { BindingPlayer _Player = new BindingPlayer(); _Player.X = Window.Current.Bounds.Height - PlayerSprite.Height; _Player.X = ( Window.Current.Bounds.Width - PlayerSprite.Width ) / 2.0; } Of course, now we need to actually have our background object. public class BindingPlayer : INotifyPropertyChanged { private double m_X; public double X { get { return m_X; } set { m_X = value; NotifyPropertyChanged(); } }   private double m_Y; public double Y { get { return m_Y; } set { m_Y = value; NotifyPropertyChanged(); } }   public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } } I fired this baby up, and my sprite was correctly positioned on the screen. Maybe the sky wasn't falling after all. Wouldn't it be great if that was the case? I created some code to allow me to move the sprite, but nothing happened. This seems odd. So, I start debugging the application and stepping through code. Everything appears to be working. Time to dig a little deeper. After much profanity was spewed, I stumbled upon a breakthrough. The code only looked like it was working. What was really happening is that there was an exception being thrown in the background thread that I never saw. Apparently, the key call was the one to PropertyChanged. If PropertyChanged is not called on the UI thread, the UI thread ignores the call. Actually, it throws an exception and the background thread silently crashes. Of course, you'll never see this unless you're looking REALLY carefully. This seemed to be a simple problem. I just need to marshal this to the UI thread. Unfortunately, this object has no knowledge of this mythical UI Thread in which we speak. So, I had to pull the UI Thread out of thin air. Let's change our PropertyChanged call to look this. public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged( [CallerMemberName] string p_PropertyName = null ) { if( PropertyChanged != null ) Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync( Windows.UI.Core.CoreDispatcherPriority.Normal, new Windows.UI.Core.DispatchedHandler( () => { PropertyChanged( this, new PropertyChangedEventArgs( p_PropertyName ) ); } ) ); } Now, we raised our notification on the UI thread. Everything is fine, people are happy, and the world moves on. You may have noticed that I didn't await my call to the dispatcher. This was intentional. If I am trying to update a slew of sprites, I don't want thread being hung while I wait my turn. Thus, I send the message and move on. It is worth nothing that this is NOT the most efficient way to do this for game programming. We'll get to that in another blog post. However, it is perfectly acceptable for a business app that is running a background task that would like to notify the UI thread of progress on a periodic basis. It is worth noting that this code was written for a Windows Store App. You can do the same thing with WP8 and WPF. The call to the marshaler changes, but it is the same idea.

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• GRUB is not Booting Correctly

  - by msknapp

  I have a PC with three hard disks. Windows 7 is installed on the first, Ubuntu 14.04 is installed on the third. After I re-booted, it went straight to Windows 7. So I tried explicitly telling my PC to boot using the third hard disk, but that just takes me to the grub rescue prompt. I followed Scott Severence's instructions here to try and recover. Essentially, I updated grub, reinstalled grub, and then updated it again. After re-booting, absolutely nothing had changed. So instead I tried using the boot-repair tool. In the past it had failed for me, saying that I had programs running and it could not unmount drives, when I was running nothing. I never figured out how to solve that problem, but it went away when I bought another hard drive and used that for my Ubuntu installation, I don't know why. In any case, I ran the boot-repair tool and this time it said it was successful. First time for everything right? I re-booted, only to be taken straight to the grub rescue prompt. So I changed my BIOS settings to use the third hard disk for boot start up. That is the same hard drive where I have Ubuntu and grub installed, and the same one that the grub-repair tool told me to use. It still took me straight to the grub rescue prompt. So I went from not being able to boot Ubuntu, to not being able to boot either OS installed on my system. Thanks boot-repair! Boot repair gave me this URL for future troubleshooting: http://paste.ubuntu.com/8131669 When I try to boot from the third hard disk, this is my console: Loading Operating System ... error: attempt to read or write outside of disk 'hd0'. Entering rescue mode... grub rescue> grub rescue> set cmdpath=(hd0) prefix=(hd0,gpt2)/boot/grub root=hd0,gpt2 grub rescue> ls (hd0) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) (hd1) (hd2) (hd2,gpt2) (hd2,gpt1) (hd3) Those values look correct to me. I have also experimented with changing some of those values, but 'insmod normal' always throws the same error. Somebody please tell me how to fix this. I have tried everything, reinstalling grub, and running boot-repair. =========================== Update: I think the problem might be that the ubuntu installer did not partition my hard disk correctly. I booted from live USB and then launched gparted and looked at how it partitioned things. This is what gparted says: Partition, File System, Size, Used, Unused, Flags /dev/sda1 (!), unknown, 1.00 MiB, ---, ---, bios_grub /dev/sda2, ext4, 2.71 TiB, 47.30 GiB, 2.67 TiB, /dev/sda3, linux-swap, 16.00 GiB, 0.00 B, 16.00 GiB, So that first line looks problematic. It is supposed to be the /boot partition. However, it was given only 1 MiB? I am assuming that MiB is actually supposed to mean megabyte, no idea why that 'i' is there. It also says the file system is unknown. I read the answer by andrew here, and he says he had to do a custom install, explicitly configuring the boot partition. So I think that maybe Ubuntu's installer has a bug in it, where it does not set up the boot partition correctly if you are not installing on the first hard disk in your computer. I am going to try reinstalling with a custom partition scheme. I read elsewhere (askubuntu won't let me post another link) that I don't even need a /boot partition any more. So instead of following Andrew's instructions ver batim, I'm first going to try having just two partitions: one for /, and another for my 16GB swap space. Both as primary partitions. The first will be formatted as ext4. If that doesn't work, I may try again using /boot. ======================== So I did my custom install with no /boot partition, and it did not work. When I rebooted, I had an error message saying that some address did not exist. So for the hundredth time, I booted from the live USB, and ran boot-repair. Now I get this message GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted. Then try again. I feel like I'm running in circles and nobody will help me.

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• Convert Java program to C

  - by imicrothinking

  I need a bit of guidance with writing a C program...a bit of quick background as to my level, I've programmed in Java previously, but this is my first time programming in C, and we've been tasked to translate a word count program from Java to C that consists of the following: Read a file from memory Count the words in the file For each occurrence of a unique word, keep a word counter variable Print out the top ten most frequent words and their corresponding occurrences Here's the source program in Java: package lab0; import java.io.File; import java.io.FileReader; import java.util.ArrayList; import java.util.Calendar; import java.util.Collections; public class WordCount { private ArrayList<WordCountNode> outputlist = null; public WordCount(){ this.outputlist = new ArrayList<WordCountNode>(); } /** * Read the file into memory. * * @param filename name of the file. * @return content of the file. * @throws Exception if the file is too large or other file related exception. */ public char[] readFile(String filename) throws Exception{ char [] result = null; File file = new File(filename); long size = file.length(); if (size > Integer.MAX_VALUE){ throw new Exception("File is too large"); } result = new char[(int)size]; FileReader reader = new FileReader(file); int len, offset = 0, size2read = (int)size; while(size2read > 0){ len = reader.read(result, offset, size2read); if(len == -1) break; size2read -= len; offset += len; } return result; } /** * Make article word by word. * * @param article the content of file to be counted. * @return string contains only letters and "'". */ private enum SPLIT_STATE {IN_WORD, NOT_IN_WORD}; /** * Go through article, find all the words and add to output list * with their count. * * @param article the content of the file to be counted. * @return words in the file and their counts. */ public ArrayList<WordCountNode> countWords(char[] article){ SPLIT_STATE state = SPLIT_STATE.NOT_IN_WORD; if(null == article) return null; char curr_ltr; int curr_start = 0; for(int i = 0; i < article.length; i++){ curr_ltr = Character.toUpperCase( article[i]); if(state == SPLIT_STATE.IN_WORD){ article[i] = curr_ltr; if ((curr_ltr < 'A' || curr_ltr > 'Z') && curr_ltr != '\'') { article[i] = ' '; //printf("\nthe word is %s\n\n",curr_start); if(i - curr_start < 0){ System.out.println("i = " + i + " curr_start = " + curr_start); } addWord(new String(article, curr_start, i-curr_start)); state = SPLIT_STATE.NOT_IN_WORD; } }else{ if (curr_ltr >= 'A' && curr_ltr <= 'Z') { curr_start = i; article[i] = curr_ltr; state = SPLIT_STATE.IN_WORD; } } } return outputlist; } /** * Add the word to output list. */ public void addWord(String word){ int pos = dobsearch(word); if(pos >= outputlist.size()){ outputlist.add(new WordCountNode(1L, word)); }else{ WordCountNode tmp = outputlist.get(pos); if(tmp.getWord().compareTo(word) == 0){ tmp.setCount(tmp.getCount() + 1); }else{ outputlist.add(pos, new WordCountNode(1L, word)); } } } /** * Search the output list and return the position to put word. * @param word is the word to be put into output list. * @return position in the output list to insert the word. */ public int dobsearch(String word){ int cmp, high = outputlist.size(), low = -1, next; // Binary search the array to find the key while (high - low > 1) { next = (high + low) / 2; // all in upper case cmp = word.compareTo((outputlist.get(next)).getWord()); if (cmp == 0) return next; else if (cmp < 0) high = next; else low = next; } return high; } public static void main(String args[]){ // handle input if (args.length == 0){ System.out.println("USAGE: WordCount <filename> [Top # of results to display]\n"); System.exit(1); } String filename = args[0]; int dispnum; try{ dispnum = Integer.parseInt(args[1]); }catch(Exception e){ dispnum = 10; } long start_time = Calendar.getInstance().getTimeInMillis(); WordCount wordcount = new WordCount(); System.out.println("Wordcount: Running..."); // read file char[] input = null; try { input = wordcount.readFile(filename); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); System.exit(1); } // count all word ArrayList<WordCountNode> result = wordcount.countWords(input); long end_time = Calendar.getInstance().getTimeInMillis(); System.out.println("wordcount: completed " + (end_time - start_time)/1000000 + "." + (end_time - start_time)%1000000 + "(s)"); System.out.println("wordsort: running ..."); start_time = Calendar.getInstance().getTimeInMillis(); Collections.sort(result); end_time = Calendar.getInstance().getTimeInMillis(); System.out.println("wordsort: completed " + (end_time - start_time)/1000000 + "." + (end_time - start_time)%1000000 + "(s)"); Collections.reverse(result); System.out.println("\nresults (TOP "+ dispnum +" from "+ result.size() +"):\n" ); // print out result String str ; for (int i = 0; i < result.size() && i < dispnum; i++){ if(result.get(i).getWord().length() > 15) str = result.get(i).getWord().substring(0, 14); else str = result.get(i).getWord(); System.out.println(str + " - " + result.get(i).getCount()); } } public class WordCountNode implements Comparable{ private String word; private long count; public WordCountNode(long count, String word){ this.count = count; this.word = word; } public String getWord() { return word; } public void setWord(String word) { this.word = word; } public long getCount() { return count; } public void setCount(long count) { this.count = count; } public int compareTo(Object arg0) { // TODO Auto-generated method stub WordCountNode obj = (WordCountNode)arg0; if( count - obj.getCount() < 0) return -1; else if( count - obj.getCount() == 0) return 0; else return 1; } } } Here's my attempt (so far) in C: #include <stdio.h> #include <stdlib.h> #include <stdbool.h> #include <string.h> // Read in a file FILE *readFile (char filename[]) { FILE *inputFile; inputFile = fopen (filename, "r"); if (inputFile == NULL) { printf ("File could not be opened.\n"); exit (EXIT_FAILURE); } return inputFile; } // Return number of words in an array int wordCount (FILE *filePointer, char filename[]) {//, char *words[]) { // count words int count = 0; char temp; while ((temp = getc(filePointer)) != EOF) { //printf ("%c", temp); if ((temp == ' ' || temp == '\n') && (temp != '\'')) count++; } count += 1; // counting method uses space AFTER last character in word - the last space // of the last character isn't counted - off by one error // close file fclose (filePointer); return count; } // Print out the frequencies of the 10 most frequent words in the console int main (int argc, char *argv[]) { /* Step 1: Read in file and check for errors */ FILE *filePointer; filePointer = readFile (argv[1]); /* Step 2: Do a word count to prep for array size */ int count = wordCount (filePointer, argv[1]); printf ("Number of words is: %i\n", count); /* Step 3: Create a 2D array to store words in the file */ // open file to reset marker to beginning of file filePointer = fopen (argv[1], "r"); // store words in character array (each element in array = consecutive word) char allWords[count][100]; // 100 is an arbitrary size - max length of word int i,j; char temp; for (i = 0; i < count; i++) { for (j = 0; j < 100; j++) { // labels are used with goto statements, not loops in C temp = getc(filePointer); if ((temp == ' ' || temp == '\n' || temp == EOF) && (temp != '\'') ) { allWords[i][j] = '\0'; break; } else { allWords[i][j] = temp; } printf ("%c", allWords[i][j]); } printf ("\n"); } // close file fclose (filePointer); /* Step 4: Use a simple selection sort algorithm to sort 2D char array */ // PStep 1: Compare two char arrays, and if // (a) c1 > c2, return 2 // (b) c1 == c2, return 1 // (c) c1 < c2, return 0 qsort(allWords, count, sizeof(char[][]), pstrcmp); /* int k = 0, l = 0, m = 0; char currentMax, comparedElement; int max; // the largest element in the current 2D array int elementToSort = 0; // elementToSort determines the element to swap with starting from the left // Outer a iterates through number of swaps needed for (k = 0; k < count - 1; k++) { // times of swaps max = k; // max element set to k // Inner b iterates through successive elements to fish out the largest element for (m = k + 1; m < count - k; m++) { currentMax = allWords[k][l]; comparedElement = allWords[m][l]; // Inner c iterates through successive chars to set the max vars to the largest for (l = 0; (currentMax != '\0' || comparedElement != '\0'); l++) { if (currentMax > comparedElement) break; else if (currentMax < comparedElement) { max = m; currentMax = allWords[m][l]; break; } else if (currentMax == comparedElement) continue; } } // After max (count and string) is determined, perform swap with temp variable char swapTemp[1][20]; int y = 0; do { swapTemp[0][y] = allWords[elementToSort][y]; allWords[elementToSort][y] = allWords[max][y]; allWords[max][y] = swapTemp[0][y]; } while (swapTemp[0][y++] != '\0'); elementToSort++; } */ int a, b; for (a = 0; a < count; a++) { for (b = 0; (temp = allWords[a][b]) != '\0'; b++) { printf ("%c", temp); } printf ("\n"); } // Copy rows to different array and print results /* char arrayCopy [count][20]; int ac, ad; char tempa; for (ac = 0; ac < count; ac++) { for (ad = 0; (tempa = allWords[ac][ad]) != '\0'; ad++) { arrayCopy[ac][ad] = tempa; printf("%c", arrayCopy[ac][ad]); } printf("\n"); } */ /* Step 5: Create two additional arrays: (a) One in which each element contains unique words from char array (b) One which holds the count for the corresponding word in the other array */ /* Step 6: Sort the count array in decreasing order, and print the corresponding array element as well as word count in the console */ return 0; } // Perform housekeeping tasks like freeing up memory and closing file I'm really stuck on the selection sort algorithm. I'm currently using 2D arrays to represent strings, and that worked out fine, but when it came to sorting, using three level nested loops didn't seem to work, I tried to use qsort instead, but I don't fully understand that function as well. Constructive feedback and criticism greatly welcome (...and needed)!

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• Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket - (TOTD #185)

  - by arungupta

  The WebSocket API defines different send(xxx) methods that can be used to send text and binary data. This Tip Of The Day (TOTD) will show how to send and receive text and binary data using WebSocket. TOTD #183 explains how to get started with a WebSocket endpoint using GlassFish 4. A simple endpoint from that blog looks like: @WebSocketEndpoint("/endpoint") public class MyEndpoint { public void receiveTextMessage(String message) { . . . } } A message with the first parameter of the type String is invoked when a text payload is received. The payload of the incoming WebSocket frame is mapped to this first parameter. An optional second parameter, Session, can be specified to map to the "other end" of this conversation. For example: public void receiveTextMessage(String message, Session session) {     . . . } The return type is void and that means no response is returned to the client that invoked this endpoint. A response may be returned to the client in two different ways. First, set the return type to the expected type, such as: public String receiveTextMessage(String message) { String response = . . . . . . return response; } In this case a text payload is returned back to the invoking endpoint. The second way to send a response back is to use the mapped session to send response using one of the sendXXX methods in Session, when and if needed. public void receiveTextMessage(String message, Session session) {     . . .     RemoteEndpoint remote = session.getRemote();     remote.sendString(...);     . . .     remote.sendString(...);    . . .    remote.sendString(...); } This shows how duplex and asynchronous communication between the two endpoints can be achieved. This can be used to define different message exchange patterns between the client and server. The WebSocket client can send the message as: websocket.send(myTextField.value); where myTextField is a text field in the web page. Binary payload in the incoming WebSocket frame can be received if ByteBuffer is used as the first parameter of the method signature. The endpoint method signature in that case would look like: public void receiveBinaryMessage(ByteBuffer message) {     . . . } From the client side, the binary data can be sent using Blob, ArrayBuffer, and ArrayBufferView. Blob is a just raw data and the actual interpretation is left to the application. ArrayBuffer and ArrayBufferView are defined in the TypedArray specification and are designed to send binary data using WebSocket. In short, ArrayBuffer is a fixed-length binary buffer with no format and no mechanism for accessing its contents. These buffers are manipulated using one of the views defined by one of the subclasses of ArrayBufferView listed below: Int8Array (signed 8-bit integer or char) Uint8Array (unsigned 8-bit integer or unsigned char) Int16Array (signed 16-bit integer or short) Uint16Array (unsigned 16-bit integer or unsigned short) Int32Array (signed 32-bit integer or int) Uint32Array (unsigned 16-bit integer or unsigned int) Float32Array (signed 32-bit float or float) Float64Array (signed 64-bit float or double) WebSocket can send binary data using ArrayBuffer with a view defined by a subclass of ArrayBufferView or a subclass of ArrayBufferView itself. The WebSocket client can send the message using Blob as: blob = new Blob([myField2.value]);websocket.send(blob); where myField2 is a text field in the web page. The WebSocket client can send the message using ArrayBuffer as: var buffer = new ArrayBuffer(10);var bytes = new Uint8Array(buffer);for (var i=0; i<bytes.length; i++) { bytes[i] = i;}websocket.send(buffer); A concrete implementation of receiving the binary message may look like: @WebSocketMessagepublic void echoBinary(ByteBuffer data, Session session) throws IOException {    System.out.println("echoBinary: " + data);    for (byte b : data.array()) {        System.out.print(b);    }    session.getRemote().sendBytes(data);} This method is just printing the binary data for verification but you may actually be storing it in a database or converting to an image or something more meaningful. Be aware of TYRUS-51 if you are trying to send binary data from server to client using method return type. Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) TOTD #183 - Getting Started with WebSocket in GlassFish TOTD #184 - Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Custom payloads using encoder/decoder Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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• IIS logs show sc-win32-status=64 but only through some networks

  - by wweicker

  I have an ASP.NET application running on a client server (W2k3, IIS6, .NET 2.0). FWIW, this is a Test instance, it hasn't been moved into Production yet. So it is not running under SSL, load balancing, etc. When I access one of the pages on their server from our office, the page gets hit once. Inspecting the IIS logs (c:WINDOWS\system32\LogFiles\W3SVC1) show a GET for that page, then I push a button on the page and the log file shows a POST. This seems to be working fine so far. Now when I remote into the client's network and access the page from one of their local machines, the log file shows a GET, then I push the button on the page and the log shows two POSTs at the same second. The first one shows status (sc-status, sc-substatus, sc-win32-status) 200 0 64, the second shows 200 0 0. In the log file, both POSTs are identical. Basically the log looks like this (except I masked some of the data): #Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) sc-status sc-substatus sc-win32-status 2009-08-11 20:19:32 x.x.x.x GET /File.aspx - 80 - y.y.y.y Mozilla/4.0+(compatible;+MSIE+8.0;+Windows+NT+6.0;+WOW64;+Trident/4.0;+SLCC1;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.21022;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30618;+MDDR;+OfficeLiveConnector.1.4;+OfficeLivePatch.0.0) 200 0 0 2009-08-11 20:19:45 x.x.x.x POST /File.aspx - 80 - y.y.y.y Mozilla/4.0+(compatible;+MSIE+8.0;+Windows+NT+6.0;+WOW64;+Trident/4.0;+SLCC1;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.21022;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30618;+MDDR;+OfficeLiveConnector.1.4;+OfficeLivePatch.0.0) 200 0 64 2009-08-11 20:19:45 x.x.x.x POST /File.aspx - 80 - y.y.y.y Mozilla/4.0+(compatible;+MSIE+8.0;+Windows+NT+6.0;+WOW64;+Trident/4.0;+SLCC1;+.NET+CLR+2.0.50727;+.NET+CLR+3.5.21022;+.NET+CLR+3.5.30729;+.NET+CLR+3.0.30618;+MDDR;+OfficeLiveConnector.1.4;+OfficeLivePatch.0.0) 200 0 0 The problem is, the page is getting hit twice. The database performs an operation for the first request, then the second request detects that a duplicate operation is being performed and throws an error message. The users think their operation failed, but it actually succeeded. The error description of sc-win32-status 64 is: "The specified network name is no longer available." This leads me to believe, given that both POST requests show an HTTP status of 200, that the server is successful in serving the request, but the client is never notified and resubmits the request. How can I troubleshoot this? Any ideas what could be causing this behavior on their internal network only? I should mention, this is happening at two separate client sites, but does not happen at six of our other client sites, or in our office, or connecting to any of our eight clients over the web. What could be making this reproducible 100% of the time on their local network but 0% of the time anywhere else? Update: I found a very small number of the duplicated POST requests had sc-win32-status of 995 instead of 64 as originally reported. The error description of sc-win32-status=995 is: "The I/O operation has been aborted because of either a thread exit or an application request." This doesn't make any sense (considering I have full access to the code). I still don't understand how or why this issue is occurring, but the new error code leads me to believe it may not be a network issue after all and I am now investigating the possibility of a random code bug.

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• nginx: How can I set proxy_* directives only for matching URIs?

  - by Artem Russakovskii

  I've been at this for hours and I can't figure out a clean solution. Basically, I have an nginx proxy setup, which works really well, but I'd like to handle a few urls more manually. Specifically, there are 2-3 locations for which I'd like to set proxy_ignore_headers to Set-Cookie to force nginx to cache them (nginx doesn't cache responses with Set-Cookie as per http://wiki.nginx.org/HttpProxyModule#proxy_ignore_headers). So for these locations, all I'd like to do is set proxy_ignore_headers Set-Cookie; I've tried everything I could think of outside of setting up and duplicating every config value, but nothing works. I tried: Nesting location directives, hoping the inner location which matches on my files would just set this value and inherit the rest, but that wasn't the case - it seemed to ignore anything set in the outer location, most notably proxy_pass and I end up with a 404). Specifying the proxy_cache_valid directive in an if block that matches on $request_uri, but nginx complains that it's not allowed ("proxy_cache_valid" directive is not allowed here). Specifying a variable equal to "Set-Cookie" in an if block, and then trying to set proxy_cache_valid to that variable later, but nginx isn't allowing variables for this case and throws up. It should be so simple - modifying/appending a single directive for some requests, and yet I haven't been able to make nginx do that. What am I missing here? Is there at least a way to wrap common directives in a reusable block and have multiple location blocks refer to it, after adding their own unique bits? Thank you. Just for reference, the main location / block is included below, together with my failed proxy_ignore_headers directive for a specific URI. location / { # Setup var defaults set $no_cache ""; # If non GET/HEAD, don't cache & mark user as uncacheable for 1 second via cookie if ($request_method !~ ^(GET|HEAD)$) { set $no_cache "1"; } if ($http_user_agent ~* '(iphone|ipod|ipad|aspen|incognito|webmate|android|dream|cupcake|froyo|blackberry|webos|s8000|bada)') { set $mobile_request '1'; set $no_cache "1"; } # feed crawlers, don't want these to get stuck with a cached version, especially if it caches a 302 back to themselves (infinite loop) if ($http_user_agent ~* '(FeedBurner|FeedValidator|MediafedMetrics)') { set $no_cache "1"; } # Drop no cache cookie if need be # (for some reason, add_header fails if included in prior if-block) if ($no_cache = "1") { add_header Set-Cookie "_mcnc=1; Max-Age=17; Path=/"; add_header X-Microcachable "0"; } # Bypass cache if no-cache cookie is set, these are absolutely critical for Wordpress installations that don't use JS comments if ($http_cookie ~* "(_mcnc|comment_author_|wordpress_(?!test_cookie)|wp-postpass_)") { set $no_cache "1"; } if ($request_uri ~* wpsf-(img|js)\.php) { proxy_ignore_headers Set-Cookie; } # Bypass cache if flag is set proxy_no_cache $no_cache; proxy_cache_bypass $no_cache; # under no circumstances should there ever be a retry of a POST request, or any other request for that matter proxy_next_upstream off; proxy_read_timeout 86400s; # Point nginx to the real app/web server proxy_pass http://localhost; # Set cache zone proxy_cache microcache; # Set cache key to include identifying components proxy_cache_key $scheme$host$request_method$request_uri$mobile_request; # Only cache valid HTTP 200 responses for this long proxy_cache_valid 200 15s; #proxy_cache_min_uses 3; # Serve from cache if currently refreshing proxy_cache_use_stale updating timeout; # Send appropriate headers through proxy_set_header Host $host; # no need for this proxy_set_header X-Real-IP $remote_addr; # no need for this proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; # Set files larger than 1M to stream rather than cache proxy_max_temp_file_size 1M; access_log /var/log/nginx/androidpolice-microcache.log custom; }

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• Cannot connect to MySQL over TCP locally - Connection Timeout - Ubuntu 9.04

  - by gav

  I am running Ubuntu and am ultimately trying to connect Tomcat to my MySQL database using JDBC. It has worked previously but after a reboot the instance now fails to connect. Both Tomcat 6 and MySQL 5.0.75 are on the same machine Connection string: jdbc:mysql:///localhost:3306 I can connect to MySQL on the command line using the mysql command The my.cnf file is pretty standard (Available on request) has bind address: 127.0.0.1 I cannot Telnet to the MySQL port despite netstat saying MySQL is listening I have one IpTables rule to forward 80 - 8080 and no firewall I'm aware of. I'm pretty new to this and I'm not sure what else to test. I don't know whether I should be looking in etc/interfaces and if I did what to look for. It's weird because it used to work but after a reboot it's down so I must have changed something.... :). I realise a timeout indicates the server is not responding and I assume it's because the request isn't actually getting through. I installed MySQL via apt-get and Tomcat manually. MySqld processes root@88:/var/log/mysql# ps -ef | grep mysqld root 21753 1 0 May27 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe mysql 21792 21753 0 May27 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --skip-external-locking --port=3306 --socket=/var/run/mysqld/mysqld.sock root 21793 21753 0 May27 ? 00:00:00 logger -p daemon.err -t mysqld_safe -i -t mysqld root 21888 13676 0 11:23 pts/1 00:00:00 grep mysqld Netstat root@88:/var/log/mysql# netstat -lnp | grep mysql tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 21792/mysqld unix 2 [ ACC ] STREAM LISTENING 1926205077 21792/mysqld /var/run/mysqld/mysqld.sock Toy Connection Class root@88:~# cat TestConnect/TestConnection.java import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class TestConnection { public static void main(String args[]) throws Exception { Connection con = null; try { Class.forName("com.mysql.jdbc.Driver").newInstance(); System.out.println("Got driver"); con = DriverManager.getConnection( "jdbc:mysql:///localhost:3306", "uname", "pass"); System.out.println("Got connection"); if(!con.isClosed()) System.out.println("Successfully connected to " + "MySQL server using TCP/IP..."); } finally { if(con != null) con.close(); } } } Toy Connection Class Output Note: This is the same error I get from Tomcat. root@88:~/TestConnect# java -cp mysql-connector-java-5.1.12-bin.jar:. TestConnection Got driver Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 1 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at TestConnection.main(TestConnection.java:14) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2181) ... 12 more Caused by: java.net.ConnectException: Connection timed out at java.net.PlainSocketImpl.socketConnect(Native Method) ... 13 more Telnet Output root@88:~/TestConnect# telnet localhost 3306 Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection timed out

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• WSUS 3.0 SP2 installation fails at "configuring database" step.

  - by flashkube

  Attempting to install WSUS 3.0 SP2 on a Windows Server 2003 Enterprise system. I'm asking the setup to create a new database on one of our existing SQL Server 2005 systems. When the setup gets to the "configuring database" step it stops and throws "There is a problem with this Windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor." The two logs it suggests I look at are below. I'm not seeing any errors that mean anything to me. Any direction you can give will be greatly appreciated. WSUSSetup.log: 2009-12-04 15:26:21 Success MWUSSetup Validating pre-requisites... 2009-12-04 15:26:22 Error MWUSSetup Failed to determine if an higher version of WSUS is installed. Assuming it is not... (Error 0x80070002: The system cannot find the file specified.) 2009-12-04 15:26:28 Success MWUSSetup No SQL instances found 2009-12-04 15:26:42 Success MWUSSetup Initializing installation details 2009-12-04 15:26:42 Success MWUSSetup Installing ASP.Net 2009-12-04 15:27:24 Success MWUSSetup ASP.Net is installed successfully 2009-12-04 15:27:24 Success MWUSSetup Installing WSUS... 2009-12-04 15:27:28 Success CustomActions.Dll Unable to get INSTALL_LANGUAGE property, calculating it... 2009-12-04 15:27:28 Success CustomActions.Dll Successfully set propery of WSUS admin groups' full names 2009-12-04 15:27:29 Success CustomActions.Dll .Net framework path: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727 2009-12-04 15:27:33 Success CustomActions.Dll Creating user group: WSUS Reporters with Description: WSUS Administrators who can only run reports on the Windows Server Update Services server. 2009-12-04 15:27:33 Success CustomActions.Dll Creating WSUS Reporters user group 2009-12-04 15:27:33 Success CustomActions.Dll WSUS Reporters user group already exists 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS Reporters user group 2009-12-04 15:27:33 Success CustomActions.Dll Creating user group: WSUS Administrators with Description: WSUS Administrators can administer the Windows Server Update Services server. 2009-12-04 15:27:33 Success CustomActions.Dll Creating WSUS Administrators user group 2009-12-04 15:27:33 Success CustomActions.Dll WSUS Administrators user group already exists 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS Administrators user group 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS user groups 2009-12-04 15:27:33 Success CustomActions.Dll Succesfully set binary SID property 2009-12-04 15:27:33 Success CustomActions.Dll Succesfully set binary SID property 2009-12-04 15:27:33 Success CustomActions.Dll Successfully set binary SID properties 2009-12-04 15:28:50 Error MWUSSetup InstallWsus: MWUS Installation Failed (Error 0x80070643: Fatal error during installation.) 2009-12-04 15:28:50 Error MWUSSetup CInstallDriver::PerformSetup: WSUS installation failed (Error 0x80070643: Fatal error during installation.) 2009-12-04 15:28:50 Error MWUSSetup CSetupDriver::LaunchSetup: Setup failed (Error 0x80070643: Fatal error during installation.) From the end of WSUSSetupmsi_091204_1527.log MSI (s) (58:7C) [15:28:49:860]: Note: 1: 1708 MSI (s) (58:7C) [15:28:49:860]: Product: Windows Server Update Services 3.0 SP2 -- Installation failed. MSI (s) (58:7C) [15:28:49:875]: Cleaning up uninstalled install packages, if any exist MSI (s) (58:7C) [15:28:49:875]: MainEngineThread is returning 1603 MSI (s) (58:78) [15:28:49:985]: Destroying RemoteAPI object. MSI (s) (58:90) [15:28:49:985]: Custom Action Manager thread ending. === Logging stopped: 12/4/2009 15:28:49 === MSI (c) (30:54) [15:28:50:016]: Decrementing counter to disable shutdown. If counter = 0, shutdown will be denied. Counter after decrement: -1 MSI (c) (30:54) [15:28:50:016]: MainEngineThread is returning 1603 === Verbose logging stopped: 12/4/2009 15:28:50 ===

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• register_globals error in php

  - by user145862

  I was stuck up with the error directive 'register_globals' is no longer available in PHP in unknown on line 0 when tried to check the php version using "php -v" after enabling register_globals in php.ini file. I am not getting any php version info by doing so. Instead it throws the above mentioned error.After turning off this option, php info works quite well. It is very essential for me to have register_globals to be turned on.How can I have this corrected. my php.ini is as follows: ; Default Value: None ; Development Value: "GP" ; Production Value: "GP" ; http://php.net/request-order request_order = "GP" ; Whether or not to register the EGPCS variables as global variables. You may ; want to turn this off if you don't want to clutter your scripts' global scope ; with user data. ; You should do your best to write your scripts so that they do not require ; register_globals to be on; Using form variables as globals can easily lead ; to possible security problems, if the code is not very well thought of. ; register_globals = On ; Determines whether the deprecated long $HTTP_*_VARS type predefined variables ; are registered by PHP or not. As they are deprecated, we obviously don't ; recommend you use them. They are on by default for compatibility reasons but ; they are not recommended on production servers. ; Default Value: On ; Development Value: Off ; Production Value: Off ; register_long_arrays = Off ; This directive determines whether PHP registers $argv & $argc each time it ; runs. $argv contains an array of all the arguments passed to PHP when a script ; is invoked. $argc contains an integer representing the number of arguments ; that were passed when the script was invoked. These arrays are extremely ; useful when running scripts from the command line. When this directive is ; enabled, registering these variables consumes CPU cycles and memory each time ; a script is executed. For performance reasons, this feature should be disabled ; on production servers. ; Note: This directive is hardcoded to On for the CLI SAPI ; Default Value: On ; Development Value: Off ; Production Value: Off ; register_argc_argv = Off ; When enabled, the SERVER and ENV variables are created when they're first ; used (Just In Time) instead of when the script starts. If these variables ; are not used within a script, having this directive on will result in a ; performance gain. The PHP directives register_globals, register_long_arrays, ; and register_argc_argv must be disabled for this directive to have any affect. ; auto_globals_jit = On

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• gallery2 and nginx with rewrite return file not found for file name with space (or + sign in url)

  - by Vangel

  I have setup nginx with gallery2 on an internal server. Everything works fine under apache2 which I checked first, it used to be on apache2 Problem is: gallery2 seems to generate url with + sign in it for file names/ images which had spaces in it so a file like "may report.jpg" becomes "may+report.jpg" The URL rewrite works but gallery2 throws an error for file not found. THis does not happen under apache2. Here is my nginx rewrite rule: location / { index main.php index.html; default_type text/html; # If the file exists as a static file serve it # directly without running all # the other rewite tests on it if (-f $request_filename) { break; } } location /v/ { # if ($request_uri !~ /main.php) # { rewrite ^/v/(.*)$ /main.php?g2_view=core.ShowItem&g2_path=$1 last; # } } location /d/ { if ($request_uri !~ /main.php) { rewrite ^/d/([0-9]+)-([0-9]+)/(.*)$ /main.php?g2_view=core.DownloadItem&g2_itemId=$1&g2_serialNumber=$2&g2_fileName=$3 last; } } location ~ \.php$ { fastcgi_pass 127.0.0.1:8889; fastcgi_index main.php; fastcgi_intercept_errors on; # to support 404s for PHP files not found fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; fastcgi_param SERVER_NAME $host; fastcgi_read_timeout 300; } the sit on its own works fine. only the images with spaces in file name do not display in album view and also when clicking the the image for full page view will throw this error Error (ERROR_MISSING_OBJECT) : Parent 103759 path report+april+456.flv in modules/core/classes/helpers/GalleryFileSystemEntityHelper_simple.class at line 98 (GalleryCoreApi::error) in modules/core/classes/GalleryCoreApi.class at line 1853 (GalleryFileSystemEntityHelper_simple::fetchChildIdByPathComponent) in modules/core/classes/helpers/GalleryFileSystemEntityHelper_simple.class at line 53 (GalleryCoreApi::fetchChildIdByPathComponent) in modules/core/classes/GalleryCoreApi.class at line 1804 (GalleryFileSystemEntityHelper_simple::fetchItemIdByPath) in modules/rewrite/classes/RewriteSimpleHelper.class at line 45 (GalleryCoreApi::fetchItemIdByPath) in ??? at line 0 (RewriteSimpleHelper::loadItemIdFromPath) in modules/rewrite/classes/RewriteUrlGenerator.class at line 103 in modules/rewrite/classes/parsers/modrewrite/ModRewriteUrlGenerator.class at line 37 (RewriteUrlGenerator::_onLoad) in init.inc at line 147 (ModRewriteUrlGenerator::initNavigation) in main.php at line 180 in main.php at line 94 in main.php at line 83 System Information Gallery version 2.2.4 PHP version 5.3.6 fpm-fcgi Webserver nginx/0.8.55 Database mysqli 5.0.95 Toolkits ImageMagick, Thumbnail, Gd Operating system Linux CentOS-55-64-minimal 2.6.18-274.18.1.el5 #1 SMP Thu Feb 9 12:45:44 EST 2012 x86_64 Browser Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.52 Safari/536.5 In the report above there is usable system information if that helps. I know the nginx is old but it comes as default in centos repo and I am not sure if upgrading will fix the problem or break something else it seems gallery2 must map the + to space internally but why it's not doing so with nginx I can't tell. EDIT: I just verified that if I change the '+' sign to %20 then gallery2 works. but gallery2 is generating URL as +. I found a (maybe) related problem here for IIS7 and Gallery2 http://forums.asp.net/t/1431951.aspx EDIT2: Accessing the URL without rewrite and having the + sign works. Must be something to do with rewrite. Here is the relevant apache2 rule that might be of help RewriteCond %{THE_REQUEST} /d/([0-9]+)-([0-9]+)/([^/?]+)(\?.|\ .) RewriteCond %{REQUEST_URI} !/main\.php$ RewriteRule . /main.php?g2_view=core.DownloadItem&g2_itemId=%1&g2_serialNumber=%2&g2_fileName=%3 [QSA,L] RewriteCond %{THE_REQUEST} /v/([^?]+)(\?.|\ .) RewriteCond %{REQUEST_URI} !/main\.php$ RewriteRule . /main.php?g2_path=%1 [QSA,L]

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• Setting up a minimalist linux environment

  - by Nate

  All right, I've been messing around with various linux distros and a variety of window managers (I seem to change operating systems like most people change their pants), and I've gotten to the point where I know what I want but I'm not sure the best way to set it up. Here's what I want out of my programming machine: I don't want a status bar. I don't want a menu bar. When there are no windows open, the screen should show my desktop background and nothing else. I'll use alt+f2 to run things, and my shell prompt will tell me my battery life and the time. I'll open network controls and volume controls when I need them, no need for them to pollute the screen all the time. I want a good, simple terminal emulator. I'll be using it with tmux. It should have no title bar and, if possible, no app frame. It's ok if I have to run it in full screen mode to remove the app frame, but only if it still plays nicely with alt-tab and workspaces. I want a dirt-simple window manager. It needs to support transparency: I don't have a lot of screen real-estate and I often overlay the terminal on the browser and type out commands. I don't want a tiling-only system, for the above reason. Bonus points for tiling and overlaying. I'd like multiple workspaces. I prefer to have one gui per workspace. If I could 'pin' the terminal emulator to always show up in each workspace, that's bonus points. If not, I can have a terminal emulator in each workspace attached to the same tmux instance. I'd like a way to set up a keypress that always takes me to the current open terminal emulator. Currently, 90% of the time I only have two windows open: the terminal emulator and something else. In this scenario, alt-tab works like a toggle between the two. If I have another gui open (like a developer window with a web browser), this throws a wrench in my workflow. I'd like a way to assign, for example, 'super-T' to switch to the first open terminal emulator. Bonus points if I can also assign 'super-B' (or whatever) to switch to the first open browser. So far I've been messing around with gnome and tweaking it heavily to match my preferences, but that seems like overkill and I can never get it quite right. I've toyed with xmonad, but it's more for handling many windows, and I usually only have the two. and am considering fluxbox, but I was wondering if any of your minimalists out there had suggestions that might better match my workflow. I'm sick of fighting the window manager, I just want it to get out of my way. Edit: To make things clear, I am not considering switching to a mac/windows environment. I find programming in windows to be a bore, and I have no interest in buying new (read: mac) hardware. Thanks! -Nate

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• How to troubleshoot a PHP script that causes a Segmenation Fault?

  - by johnlai2004

  I posted this on stackoverflow.com as well because I'm not sure if this is a programming problem or a server problem. I'm using ubuntu 9.10, apache2, mysql5 and php5. I've noticed an unusual problem with some of my php programs. Sometimes when visiting a page like profile.edit.php, the browser throws a dialogue box asking to download profile.edit.php page. When I download it, there's nothing in the file. profile.edit.php is supposed to be a web form that edits user information. I've noticed this on some of my other php pages as well. I look in my apache error logs, and I see a segmentation fault message: [Mon Mar 08 15:40:10 2010] [notice] child pid 480 exit signal Segmentation fault (11) And also, the issue may or may not appear depending on which server I deploy my application too. Additonal Details This doesn't happen all the time though. It only happens sometimes. For example, profile.edit.php will load properly. But as soon as I hit the save button (form action="profile.edit.php?save=true"), then the page asks me to download profile.edit.php. Could it be that sometimes my php scripts consume too much resources? Sample code Upon save action, my profile.edit.php includes a data_access_object.php file. I traced the code in data_access_object.php to this line here if($params[$this->primaryKey]) { $q = "UPDATE $this->tableName SET ".implode(', ', $fields)." WHERE ".$this->primaryKey." = ?$this->primaryKey"; $this->bind($this->primaryKey, $params[$this->primaryKey], $this->tblFields[$this->primaryKey]['mysqlitype']); } else { $q = "INSERT $this->tableName SET ".implode(', ', $fields); } // Code executes perfectly up to this point // echo 'print this'; exit; // if i uncomment this line, profile.edit.php will actually show 'print this'. If I leave it commented, the browser will ask me to download profile.edit.php if(!$this->execute($q)){ $this->errorSave = -3; return false;} // When I jumped into the function execute(), every line executed as expected, right up to the return statement. And if it helps, here's the function execute($sql) in data_access_object.php function execute($sql) { // find all list types and explode them // eg. turn ?listId into ?listId0,?listId1,?listId2 $arrListParam = array_bubble_up('arrayName', $this->arrBind); foreach($arrListParam as $listName) if($listName) { $explodeParam = array(); $arrList = $this->arrBind[$listName]['value']; foreach($arrList as $key=>$val) { $newParamName = $listName.$key; $this->bind($newParamName,$val,$this->arrBind[$listName]['type']); $explodeParam[] = '?'.$newParamName; } $sql = str_replace("?$listName", implode(',',$explodeParam), $sql); } // replace all ?varName with ? for syntax compliance $sqlParsed = preg_replace('/\?[\w\d_\.]+/', '?', $sql); $this->stmt->prepare($sqlParsed); // grab all the parameters from the sql to create bind conditions preg_match_all('/\?[\w\d_\.]+/', $sql, $matches); $matches = $matches[0]; // store bind conditions $types = ''; $params = array(); foreach($matches as $paramName) { $types .= $this->arrBind[str_replace('?', '', $paramName)]['type']; $params[] = $this->arrBind[str_replace('?', '', $paramName)]['value']; } $input = array('types'=>$types) + $params; // bind it if(!empty($types)) call_user_func_array(array($this->stmt, 'bind_param'), $input); $stat = $this->stmt->execute(); if($GLOBALS['DEBUG_SQL']) echo '<p style="font-weight:bold;">SQL error after execution:</p> ' . $this->stmt->error.'<p>&nbsp;</p>'; $this->arrBind = array(); return $stat; }

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• What is the best server or Ip address to use for prolonged testing?

  - by eldorel

  I usually run uptime/latency tests against (and from) two servers that we own at different sites and until recently I've used the google dns servers as a control group. However, I've realized there is a potential problem with monitoring latency over extended periods of time. Almost all of the major service providers are using ANYCAST. For short tests this doesn't matter, but I need to run a set of tests for at least a week to try and catch an intermittent problem, and a change in the anycast priority while trying to test latency will cause the latency values for that server to change accordingly. Since I'm submitting graphs of this data to the ISP, I need to avoid/account for as many variables as possible. Spikes in the data for only one of the tested servers will only cause headaches. So can anyone recommend servers that: are not using anycast are owned by an entity that has a good uptime reputation (so they can't claim that the problem is server-side) will respond to ICMP requests Have an available service that runs on TCP/UDP (http or dns preferably) Wont consider an automated request every 10 minutes to be abuse Are accessible from anywhere in the world Are not local to the isp ( consider this an investigation of a hostile party ) Thanks in advance. Edit: added #6 and #7 above. More info: I am attempting to demonstrate a network problem for an entire node of our local ISP's network. They are actively blaming the issue on the equipment installed at the customer sites (our backup site is one of these), and refuse to escalate the problem. (even though 2 of these businesses have ISP provided modems, and all of us have completely different routers/services running) I am already quite familiar with the need to test an isp controlled IP, but they are actively dropping all packets targeted at gateway ip addresses and are only passing traffic addressed beyond the gateways. So to demonstrate the issue, I am sending packets to other systems in the same node, systems one hop away from the affected node, and systems completely outside the network. Unfortunately, all of the systems I have currently are either administered directly by myself, or by people who are biased enough to assist me. I need to have several systems included in the trace/log/graphs that are 100% not in the control of either myself or the isp so that the graphs have a stable/unbiased control group. These requirements are straight from legal, I'm just trying to make sure that everything that could be argued to invalidate the data is already covered. In Summary: I need to be able to show tcp/udp/icmp as 3 separate data points, and I need to be able to show the connections inside the local node, from local node to another nearby node, from those 2 nodes to the internet, and through the internet to both verifiable servers and a control group that I have no control over whatsoever. Again, Google/opendns/yahoo/msn/facebook/etc all use anycast, which throws the numbers off every time the anycast caches expire, so I need suggestions of an IP or server that is available for this type of testing. I was hoping someone knew of a system run by someone such as ISC or ICANN, or perhaps even a .gov server (fcc or nsa maybe?) setup for this type of testing. Thanks again.

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• Tomcat and ASP site under IIS6 with SSL

  - by Rafe

  I've been working on migrating our companies' website from it's original server to a new one and am having two different but possibly related problems. The box this is sitting on is a Windows 2003 server x64 running IIS 6. The Tomcat version is 5.5.x as it was the version the original deployment was built on. There are two other sites on the server one in plain HTML, another in PHP and the one I am trying to migrate is a combination of Java and ASP (the introductory/sign in pages being Java as well as many reports used for our clients and the administration pages being in ASP) First of all I can only access the site if I enter the ip followed by :8080 (xxx.xxx.xxx.xxx:8080). The original setup had an index.html file in the root of the site with a bit of javascript in the header that pointed the site to 'www.mysite.com/app/public' but if I try going directly to the site without the 8080 I get a 'page not found error' and the javascript redirector causes the same problem because it doesn't add the 8080 into the URL even though on the original site the 8080 wasn't present so I don't understand why it would need it now. The js redirect looks like this: <script language="JavaScript"> <!-- location.href = "/app/public/" location.replace("/app/public/"); //--> </script> When setting the site up I used the command line to unbind IIS from all of the ip's on the system (there are 12 ip's on this box) because I was led to believe Tomcat wanted to use localhost which wasn't accessible. I'm not sure if this was the right thing to do but I'm throwing it in for the sake of completeness. And actually, at this point trying to go to localhost from the server itself throws up a 'could not connect to localhost' error. If I go to localhost:8080 I get the tomcat welcome page. If I do localhost:8080/app/public I get the intro page to our website. So I'm not sure what I'm even looking at in this case, that is what the proper behavior should be. The second part of the problem is that if I do go to either the ip or localhost such as above (localhost:8080/app/public) and click on our login link it is supposed to transfer me to our login page yet instead I receive a 'could not connect' error and the url has changed to localhost:8443/app/secure. From my research I see that port 8443 is Tomcats SSL port and the server.xml alludes to it as follows: <Connector port="8080" maxHttpHeaderSize="8192" maxThreads="150" minSpareThreads="25" maxSpareThreads="75" enableLookups="false" redirectPort="8443" acceptCount="100" connectionTimeout="20000" disableUploadTimeout="true" /> I have an SSL certificate assigned to the site via IIS and was under the impression that by default Tomcat allowed IIS to handle secure connections but apparently something is munged because it's not working. There is another section in the server.xml that reads like this: <Connector port="8009" enableLookups="false" redirectPort="443" protocol="AJP/1.3" /> Which I'm not sure what it is for although port 443 is the SSL port that IIS uses so I'm confused as to what this is supposed to be doing. Another question I have is when does the isap_redirector actually come into play? How does it know when to try and serve pages through Tomcat and when not to? I've hunted around the 'net for an answer and have yet to find a clear dialogue on the subject. Anyone have any pointers as to where to look for a solution to all of this?

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• VPS 512 MB RAM with WordPressMU comes to consumes lots of memory

  - by CAPitalZ

  I have googled for days and gathered all optimization suggestions and tried. My sites are not getting any high hits. May be like 100 hits per day [all my sites combined]. Here are my specs I have 512 MB RAM VPS with burstable 1024 MB. Centos 5 32-bit & cPanel/WHM Apache 2.2 MySQL 5.0 PHP 5.3.2 Here is my Configs I have 2 WordPressMU production sites, and 1 test site my.cnf # The following options will be passed to all MySQL clients [client] #password = your_password port = 3306 socket = /var/lib/mysql/mysql.sock # Here follows entries for some specific programs # The MySQL server [mysqld] port = 3306 socket = /var/lib/mysql/mysql.sock skip-locking skip-bdb skip-innodb key_buffer = 16M max_allowed_packet = 1M table_cache = 64 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M #CAPitalZ thread_cache_size=8 thread_concurrency=4 #query_cache_type=1 #query_cache_limit=1M query_cache_size=16M concurrent_insert=2 low_priority_updates=1 max_connections=50 tmp_table_size=16M max_heap_table_size=16M join_buffer_size=1M interactive_timeout=25 wait_timeout=1000 #connect_timout=10 not able to restart mysql max_connect_errors=10 # Don't listen on a TCP/IP port at all. This can be a security enhancement, # if all processes that need to connect to mysqld run on the same host. # All interaction with mysqld must be made via Unix sockets or named pipes. # Note that using this option without enabling named pipes on Windows # (via the "enable-named-pipe" option) will render mysqld useless! # skip-networking # Disable Federated by default skip-federated # Replication Master Server (default) # binary logging is required for replication log-bin=mysql-bin # required unique id between 1 and 2^32 - 1 # defaults to 1 if master-host is not set # but will not function as a master if omitted server-id = 1 [mysqld_safe] open_files_limit=8192 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash # Remove the next comment character if you are not familiar with SQL #safe-updates [isamchk] key_buffer = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [myisamchk] key_buffer = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout httpd.conf I have unselected many modules and recompiled using EasyApache in WHM. Only have the following modules built Deflate Expires Fileprotect Imagemap MPM Prefork Version [default] EAccelerator for PHP Bcmath Calendar CurlSSL [I'm using Curl. But I don't have any https sites] Expat GD [for image cropping] Gettext Imap Mbregex [default] Mbstring [need both Mbregex and Mbstring for utf-8] Mysql of the system MySQL "Improved" extension. Sockets TTF (FreeType) [I'm using custom font] Zlib Under Global Configuration I only have FollowSymLinks enabled I Have TraceEnable, ServerSignature, FileETag OFF ServerTokens ProductOnly DirectoryIndex Priority has index.php as the first one I have removed Clamd [Clam Anti-virus] SpamAssasin is Off Under Tweak Settings Default catch-all/default address behavior for new accounts. This is set to "fail" All stats programs turned off I have eAccelerator installed and checked in phpinfo and its working [Pre VirtualHost Include under WHM] Timeout 20 KeepAlive On MaxKeepAliveRequests 200 KeepAliveTimeout 3 MinSpareServers 1 MaxSpareServers 3 StartServers 1 ServerLimit 50 MaxClients 50 MaxRequestsPerChild 4000 ExtendedStatus Off #ServerType standalone this throws error HostnameLookups Off <Directory "/"> AllowOverride None </Directory> My sites will take ages to load and WHM/CPanel will not even load. adadaa.com/ http://adadaa.net/ kadais.ca/ My average memory consumption is like 1000 MB! [yes always bursting] The process that consumes most CPU and also most memory is mysql But I also get like 15 httpd processes [when its bursting] I already got warning from cpuwatchcheck saying "While processing, the cpu has been maxed out for more than a 6 hour period. The current load/uptime line on the server at the time of this email is 07:00:37 up 11:30, 0 users, load average: 14.64, 16.79, 20.07" I don't know, I have tried switching these config values many different times, but nothing seems to work. Please show some light... Thanks

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• Why Moq is thorwing "expected Invocation on the mock at least once". Where as it is being set once,e

  - by Mohit

  Following is the code. create a class lib add the ref to NUnit framework 2.5.3.9345 and Moq.dll 4.0.0.0 and paste the following code. Try running it on my machine it throws TestCase 'MoqTest.TryClassTest.IsMessageNotNull' failed: Moq.MockException : Expected invocation on the mock at least once, but was never performed: v = v.Model = It.Is(value(Moq.It+<c__DisplayClass21[MoqTest.GenInfo]).match) at Moq.Mock.ThrowVerifyException(IProxyCall expected, Expression expression, Times times, Int32 callCount) at Moq.Mock.VerifyCalls(Interceptor targetInterceptor, MethodCall expected, Expression expression, Times times) at Moq.Mock.VerifySet[T](Mock1 mock, Action1 setterExpression, Times times, String failMessage) at Moq.Mock1.VerifySet(Action`1 setterExpression) Class1.cs(22,0): at MoqTest.TryClassTest.IsMessageNotNull() using System; using System.Collections.Generic; using System.Linq; using System.Text; using Moq; using NUnit.Framework; namespace MoqTest { [TestFixture] public class TryClassTest { [Test] public void IsMessageNotNull() { var mockView = new Mock<IView<GenInfo>>(); mockView.Setup(v => v.ModuleId).Returns(""); TryPresenter tryPresenter = new TryPresenter(mockView.Object); tryPresenter.SetMessage(new object(), new EventArgs()); // mockView.VerifySet(v => v.Message, Times.AtLeastOnce()); mockView.VerifySet(v => v.Model = It.Is<GenInfo>(x => x != null)); } } public class TryPresenter { private IView<GenInfo> view; public TryPresenter(IView<GenInfo> view) { this.view = view; } public void SetMessage(object sender, EventArgs e) { this.view.Model = null; } } public class MyView : IView<GenInfo> { #region Implementation of IView<GenInfo> public string ModuleId { get; set; } public GenInfo Model { get; set; } #endregion } public interface IView<T> { string ModuleId { get; set; } T Model { get; set; } } public class GenInfo { public String Message { get; set; } } } And if you change one line mockView.VerifySet(v = v.Model = It.Is(x = x != null)); to mockView.VerifySet(v = v.Model, Times.AtLeastOnce()); it works fine. I think Exception is incorrect.

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• Json.Net Issues: StackOverflowException is thrown when serialising circular dependent ISerializable object with ReferenceLoopHandling.Ignore

  - by keyr

  I have a legacy application that used binary serialisation to persist the data. Now we wanted to use Json.net 4.5 to serialise the data without much changes to the existing classes. Things were working nice till we hit a circular dependent class. Is there any workaround to solve this problem? Sample code as shown below [Serializable] class Department : ISerializable { public Employee Manager { get; set; } public string Name { get; set; } public Department() { } public Department( SerializationInfo info, StreamingContext context ) { Manager = ( Employee )info.GetValue( "Manager", typeof( Employee ) ); Name = ( string )info.GetValue( "Name", typeof( string ) ); } public void GetObjectData( SerializationInfo info, StreamingContext context ) { info.AddValue( "Manager", Manager ); info.AddValue( "Name", Name ); } } [Serializable] class Employee : ISerializable { [NonSerialized] //This does not work [XmlIgnore]//This does not work private Department mDepartment; public Department Department { get { return mDepartment; } set { mDepartment = value; } } public string Name { get; set; } public Employee() { } public Employee( SerializationInfo info, StreamingContext context ) { Department = ( Department )info.GetValue( "Department", typeof( Department ) ); Name = ( string )info.GetValue( "Name", typeof( string ) ); } public void GetObjectData( SerializationInfo info, StreamingContext context ) { info.AddValue( "Department", Department ); info.AddValue( "Name", Name ); } } And the test code Department department = new Department(); department.Name = "Dept1"; Employee emp1 = new Employee { Name = "Emp1", Department = department }; department.Manager = emp1; Employee emp2 = new Employee() { Name = "Emp2", Department = department }; IList<Employee> employees = new List<Employee>(); employees.Add( emp1 ); employees.Add( emp2 ); var memoryStream = new MemoryStream(); var formatter = new BinaryFormatter(); formatter.Serialize( memoryStream, employees ); memoryStream.Seek( 0, SeekOrigin.Begin ); IList<Employee> deserialisedEmployees = formatter.Deserialize( memoryStream ) as IList<Employee>; //Works nicely JsonSerializerSettings jsonSS= new JsonSerializerSettings(); jsonSS.TypeNameHandling = TypeNameHandling.Objects; jsonSS.TypeNameAssemblyFormat = FormatterAssemblyStyle.Full; jsonSS.Formatting = Formatting.Indented; jsonSS.ReferenceLoopHandling = ReferenceLoopHandling.Ignore; //This is not working!! //jsonSS.ReferenceLoopHandling = ReferenceLoopHandling.Serialize; //This is also not working!! jsonSS.PreserveReferencesHandling = PreserveReferencesHandling.All; string jsonAll = JsonConvert.SerializeObject( employees, jsonSS ); //Throws stackoverflow exception Edit1: The issue has been reported to Json (http://json.codeplex.com/workitem/23668)

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• No mapping found for HTTP request with URI: in a Spring MVC app

  - by Ravi

  Hello All, I'm getting this error. my web.xml has this <servlet> <servlet-name>springweb</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/web-application-config.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springweb</servlet-name> <url-pattern>/app/*</url-pattern> </servlet-mapping> I have this in my web-application-config.xml <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> </bean> <bean name="/Scheduling.htm" class="com.web.SchedulingController"/> my com.web.SchedulingController looks like this /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package com.web; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; public class SchedulingController implements Controller{ public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView modelAndView = new ModelAndView("/jsp/Scheduling_main.jsp"); modelAndView.addObject("message","Hello World MVC!!"); return modelAndView; } } When I hit this controller with the URL http://localhost:8080/project1/app/Scheduling.htm The Scheduling_main.jsp gets displayed but the images are not displayed properly. Also the js and css file are not getting rendered. I'm accessing the images like this <img src="jquerylib/images/save_32x32.png" title="Save Appointment"> If I change the URL mapping in the servlet definition to *.htm, the images get displayed fine. Can you point out where I'm missing out. Here is complete error message WARN [PageNotFound] No mapping found for HTTP request with URI [/mavenproject1/app/jquerylib/images/save_32x32.png] in DispatcherServlet with name 'springweb' Thanks a lot. Ravi

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