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rspec undefined local variable or method `class_nesting_depth`

- by unsorted

I'm using rails 3 w/ rspec-rails 2.4.1 and I get an error during model generation. Can't find anything from googling. Anyone know what might be going on? TIA $ rails g model CourseRating student_id:integer course_id:integer difficulty:integer usefulness:integer invoke active_record create db/migrate/20110111044035_create_course_ratings.rb create app/models/course_rating.rb invoke rspec create spec/models/course_rating_spec.rb (erb):1:in `template': undefined local variable or method `class_nesting_depth' for #<Rspec::Generators::ModelGenerator:0x0000010424e460> (NameError) from /Users/glurban/.rvm/rubies/ruby-1.9.2-rc2/lib/ruby/1.9.1/erb.rb:753:in `eval' from /Users/glurban/.rvm/rubies/ruby-1.9.2-rc2/lib/ruby/1.9.1/erb.rb:753:in `result' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/file_manipulation.rb:111:in `block in template' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:54:in `call' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:54:in `render' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:63:in `block (2 levels) in invoke!' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:63:in `open' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:63:in `block in invoke!' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/empty_directory.rb:114:in `call' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/empty_directory.rb:114:in `invoke_with_conflict_check' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:61:in `invoke!' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions.rb:95:in `action' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/create_file.rb:26:in `create_file' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/actions/file_manipulation.rb:110:in `template' from /Users/glurban/code/recruitd/lib/generators/rspec/model/model_generator.rb:10:in `create_test_file' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/task.rb:22:in `run' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:118:in `invoke_task' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `block in invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `each' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `map' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:226:in `dispatch' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:109:in `invoke' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:269:in `block in _invoke_for_class_method' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/shell.rb:74:in `with_padding' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:258:in `_invoke_for_class_method' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:150:in `_invoke_from_option_test_framework' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/task.rb:22:in `run' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:118:in `invoke_task' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `block in invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `each' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `map' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:226:in `dispatch' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:109:in `invoke' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:269:in `block in _invoke_for_class_method' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/shell.rb:74:in `with_padding' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:258:in `_invoke_for_class_method' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:150:in `_invoke_from_option_orm' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/task.rb:22:in `run' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:118:in `invoke_task' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `block in invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `each' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `map' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `invoke_all' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/group.rb:226:in `dispatch' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/thor-0.14.6/lib/thor/base.rb:389:in `start' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/railties-3.0.0/lib/rails/generators.rb:163:in `invoke' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/railties-3.0.0/lib/rails/commands/generate.rb:10:in `<top (required)>' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require' from /Users/glurban/.rvm/gems/ruby-1.9.2-rc2/gems/railties-3.0.0/lib/rails/commands.rb:17:in `<top (required)>' from script/rails:6:in `require' from script/rails:6:in `<main>'

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Java ThreadPoolExecutor getting stuck while using ArrayBlockingQueue

- by Ravi Rao

Hi, I'm working on some application and using ThreadPoolExecutor for handling various tasks. ThreadPoolExecutor is getting stuck after some duration. To simulate this in a simpler environment, I've written a simple code where I'm able to simulate the issue. import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.RejectedExecutionHandler; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; public class MyThreadPoolExecutor { private int poolSize = 10; private int maxPoolSize = 50; private long keepAliveTime = 10; private ThreadPoolExecutor threadPool = null; private final ArrayBlockingQueue<Runnable> queue = new ArrayBlockingQueue<Runnable>( 100000); public MyThreadPoolExecutor() { threadPool = new ThreadPoolExecutor(poolSize, maxPoolSize, keepAliveTime, TimeUnit.SECONDS, queue); threadPool.setRejectedExecutionHandler(new RejectedExecutionHandler() { @Override public void rejectedExecution(Runnable runnable, ThreadPoolExecutor threadPoolExecutor) { System.out .println("Execution rejected. Please try restarting the application."); } }); } public void runTask(Runnable task) { threadPool.execute(task); } public void shutDown() { threadPool.shutdownNow(); } public ThreadPoolExecutor getThreadPool() { return threadPool; } public void setThreadPool(ThreadPoolExecutor threadPool) { this.threadPool = threadPool; } public static void main(String[] args) { MyThreadPoolExecutor mtpe = new MyThreadPoolExecutor(); for (int i = 0; i < 1000; i++) { final int j = i; mtpe.runTask(new Runnable() { @Override public void run() { System.out.println(j); } }); } } } Try executing this code a few times. It normally print outs the number on console and when all threads end, it exists. But at times, it finished all task and then is not getting terminated. The thread dump is as follows: MyThreadPoolExecutor [Java Application] MyThreadPoolExecutor at localhost:2619 (Suspended) Daemon System Thread [Attach Listener] (Suspended) Daemon System Thread [Signal Dispatcher] (Suspended) Daemon System Thread [Finalizer] (Suspended) Object.wait(long) line: not available [native method] ReferenceQueue<T>.remove(long) line: not available ReferenceQueue<T>.remove() line: not available Finalizer$FinalizerThread.run() line: not available Daemon System Thread [Reference Handler] (Suspended) Object.wait(long) line: not available [native method] Reference$Lock(Object).wait() line: 485 Reference$ReferenceHandler.run() line: not available Thread [pool-1-thread-1] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-2] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-3] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-4] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-6] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-8] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-5] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-10] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-9] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [pool-1-thread-7] (Suspended) Unsafe.park(boolean, long) line: not available [native method] LockSupport.park(Object) line: not available AbstractQueuedSynchronizer$ConditionObject.await() line: not available ArrayBlockingQueue<E>.take() line: not available ThreadPoolExecutor.getTask() line: not available ThreadPoolExecutor$Worker.run() line: not available Thread.run() line: not available Thread [DestroyJavaVM] (Suspended) C:\Program Files\Java\jre1.6.0_07\bin\javaw.exe (Jun 17, 2010 10:42:33 AM) In my actual application,ThreadPoolExecutor threads go in this state and then it stops responding. Regards, Ravi Rao

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Python/numpy tricky slicing problem

- by daver

Hi stack overflow, I have a problem with some numpy stuff. I need a numpy array to behave in an unusual manner by returning a slice as a view of the data I have sliced, not a copy. So heres an example of what I want to do: Say we have a simple array like this: a = array([1, 0, 0, 0]) I would like to update consecutive entries in the array (moving left to right) with the previous entry from the array, using syntax like this: a[1:] = a[0:3] This would get the following result: a = array([1, 1, 1, 1]) Or something like this: a[1:] = 2*a[:3] # a = [1,2,4,8] To illustrate further I want the following kind of behaviour: for i in range(len(a)): if i == 0 or i+1 == len(a): continue a[i+1] = a[i] Except I want the speed of numpy. The default behavior of numpy is to take a copy of the slice, so what I actually get is this: a = array([1, 1, 0, 0]) I already have this array as a subclass of the ndarray, so I can make further changes to it if need be, I just need the slice on the right hand side to be continually updated as it updates the slice on the left hand side. Am I dreaming or is this magic possible? Update: This is all because I am trying to use Gauss-Seidel iteration to solve a linear algebra problem, more or less. It is a special case involving harmonic functions, I was trying to avoid going into this because its really not necessary and likely to confuse things further, but here goes. The algorithm is this: while not converged: for i in range(len(u[:,0])): for j in range(len(u[0,:])): # skip over boundary entries, i,j == 0 or len(u) u[i,j] = 0.25*(u[i-1,j] + u[i+1,j] + u[i, j-1] + u[i,j+1]) Right? But you can do this two ways, Jacobi involves updating each element with its neighbours without considering updates you have already made until the while loop cycles, to do it in loops you would copy the array then update one array from the copied array. However Gauss-Seidel uses information you have already updated for each of the i-1 and j-1 entries, thus no need for a copy, the loop should essentially 'know' since the array has been re-evaluated after each single element update. That is to say, every time we call up an entry like u[i-1,j] or u[i,j-1] the information calculated in the previous loop will be there. I want to replace this slow and ugly nested loop situation with one nice clean line of code using numpy slicing: u[1:-1,1:-1] = 0.25(u[:-2,1:-1] + u[2:,1:-1] + u[1:-1,:-2] + u[1:-1,2:]) But the result is Jacobi iteration because when you take a slice: u[:,-2,1:-1] you copy the data, thus the slice is not aware of any updates made. Now numpy still loops right? Its not parallel its just a faster way to loop that looks like a parallel operation in python. I want to exploit this behaviour by sort of hacking numpy to return a pointer instead of a copy when I take a slice. Right? Then every time numpy loops, that slice will 'update' or really just replicate whatever happened in the update. To do this I need slices on both sides of the array to be pointers. Anyway if there is some really really clever person out there that awesome, but I've pretty much resigned myself to believing the only answer is to loop in C.

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Asp.Net MVC and ajax async callback execution order

- by lrb

I have been sorting through this issue all day and hope someone can help pinpoint my problem. I have created a "asynchronous progress callback" type functionality in my app using ajax. When I strip the functionality out into a test application I get the desired results. See image below: Desired Functionality When I tie the functionality into my single page application using the same code I get a sort of blocking issue where all requests are responded to only after the last task has completed. In the test app above all request are responded to in order. The server reports a ("pending") state for all requests until the controller method has completed. Can anyone give me a hint as to what could cause the change in behavior? Not Desired Desired Fiddler Request/Response GET http://localhost:12028/task/status?_=1383333945335 HTTP/1.1 X-ProgressBar-TaskId: 892183768 Accept: */* X-Requested-With: XMLHttpRequest Referer: http://localhost:12028/ Accept-Language: en-US Accept-Encoding: gzip, deflate User-Agent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0) Connection: Keep-Alive DNT: 1 Host: localhost:12028 HTTP/1.1 200 OK Cache-Control: private Content-Type: text/html; charset=utf-8 Vary: Accept-Encoding Server: Microsoft-IIS/8.0 X-AspNetMvc-Version: 3.0 X-AspNet-Version: 4.0.30319 X-SourceFiles: =?UTF-8?B?QzpcUHJvamVjdHNcVEVNUFxQcm9ncmVzc0Jhclx0YXNrXHN0YXR1cw==?= X-Powered-By: ASP.NET Date: Fri, 01 Nov 2013 21:39:08 GMT Content-Length: 25 Iteration completed... Not Desired Fiddler Request/Response GET http://localhost:60171/_Test/status?_=1383341766884 HTTP/1.1 X-ProgressBar-TaskId: 838217998 Accept: */* X-Requested-With: XMLHttpRequest Referer: http://localhost:60171/Report/Index Accept-Language: en-US Accept-Encoding: gzip, deflate User-Agent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0) Connection: Keep-Alive DNT: 1 Host: localhost:60171 Pragma: no-cache Cookie: ASP.NET_SessionId=rjli2jb0wyjrgxjqjsicdhdi; AspxAutoDetectCookieSupport=1; TTREPORTS_1_0=CC2A501EF499F9F...; __RequestVerificationToken=6klOoK6lSXR51zCVaDNhuaF6Blual0l8_JH1QTW9W6L-3LroNbyi6WvN6qiqv-PjqpCy7oEmNnAd9s0UONASmBQhUu8aechFYq7EXKzu7WSybObivq46djrE1lvkm6hNXgeLNLYmV0ORmGJeLWDyvA2 HTTP/1.1 200 OK Cache-Control: private Content-Type: text/html; charset=utf-8 Vary: Accept-Encoding Server: Microsoft-IIS/8.0 X-AspNetMvc-Version: 4.0 X-AspNet-Version: 4.0.30319 X-SourceFiles: =?UTF-8?B?QzpcUHJvamVjdHNcSUxlYXJuLlJlcG9ydHMuV2ViXHRydW5rXElMZWFybi5SZXBvcnRzLldlYlxfVGVzdFxzdGF0dXM=?= X-Powered-By: ASP.NET Date: Fri, 01 Nov 2013 21:37:48 GMT Content-Length: 25 Iteration completed... The only difference in the two requests headers besides the auth tokens is "Pragma: no-cache" in the request and the asp.net version in the response. Thanks Update - Code posted (I probably need to indicate this code originated from an article by Dino Esposito ) var ilProgressWorker = function () { var that = {}; that._xhr = null; that._taskId = 0; that._timerId = 0; that._progressUrl = ""; that._abortUrl = ""; that._interval = 500; that._userDefinedProgressCallback = null; that._taskCompletedCallback = null; that._taskAbortedCallback = null; that.createTaskId = function () { var _minNumber = 100, _maxNumber = 1000000000; return _minNumber + Math.floor(Math.random() * _maxNumber); }; // Set progress callback that.callback = function (userCallback, completedCallback, abortedCallback) { that._userDefinedProgressCallback = userCallback; that._taskCompletedCallback = completedCallback; that._taskAbortedCallback = abortedCallback; return this; }; // Set frequency of refresh that.setInterval = function (interval) { that._interval = interval; return this; }; // Abort the operation that.abort = function () { // if (_xhr !== null) // _xhr.abort(); if (that._abortUrl != null && that._abortUrl != "") { $.ajax({ url: that._abortUrl, cache: false, headers: { 'X-ProgressBar-TaskId': that._taskId } }); } }; // INTERNAL FUNCTION that._internalProgressCallback = function () { that._timerId = window.setTimeout(that._internalProgressCallback, that._interval); $.ajax({ url: that._progressUrl, cache: false, headers: { 'X-ProgressBar-TaskId': that._taskId }, success: function (status) { if (that._userDefinedProgressCallback != null) that._userDefinedProgressCallback(status); }, complete: function (data) { var i=0; }, }); }; // Invoke the URL and monitor its progress that.start = function (url, progressUrl, abortUrl) { that._taskId = that.createTaskId(); that._progressUrl = progressUrl; that._abortUrl = abortUrl; // Place the Ajax call _xhr = $.ajax({ url: url, cache: false, headers: { 'X-ProgressBar-TaskId': that._taskId }, complete: function () { if (_xhr.status != 0) return; if (that._taskAbortedCallback != null) that._taskAbortedCallback(); that.end(); }, success: function (data) { if (that._taskCompletedCallback != null) that._taskCompletedCallback(data); that.end(); } }); // Start the progress callback (if any) if (that._userDefinedProgressCallback == null || that._progressUrl === "") return this; that._timerId = window.setTimeout(that._internalProgressCallback, that._interval); }; // Finalize the task that.end = function () { that._taskId = 0; window.clearTimeout(that._timerId); } return that; };

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How do I add the j2ee.jar to a Java2WSDL ant script programmatically?

- by Marcus

I am using IBM's Rational Application Developer. I have an ant script that contains the Java2WSDL task. When I run it via IBM, it gives compiler errors unless I include the j2ee.jar file in the classpath via the run tool (it does not pick up the jar files in the classpath in the script). However, I need to be able to call this script programmatically, and it is giving me this error: "java.lang.NoClassDefFoundError: org.eclipse.core.runtime.CoreException" I'm not sure which jars need to be added or where? Since a simple echo script runs, I assume that it is the j2ee.jar or another ant jar that needs to be added. I've added it to the project's buildpath, but that doesn't help. (I also have ant.jar, wsanttasks.jar, all the ant jars from the plugin, tools.jar, remoteAnt.jar, and the swt - all which are included in the buildpath when you run the script by itself.) Script: <?xml version="1.0" encoding="UTF-8"?> <project default="build" basedir="."> <path id="lib.path"> <fileset dir="C:\Program Files\IBM\WebSphere\AppServer\lib" includes="*.jar"/>  </path> <taskdef name="java2wsdl" classname="com.ibm.websphere.ant.tasks.Java2WSDL"> <classpath refid="lib.path"/> </taskdef> <target name="build"> <echo message="Beginning build"/> <javac srcdir="C:\J2W_Test\Java2Wsdl_Example" destdir="C:\J2W_Test\Java2Wsdl_Example"> <classpath refid="lib.path"/> <include name="WSExample.java"/> </javac> <echo message="Set up javac"/> <echo message="Running java2wsdl"/> <java2wsdl output="C:\J2W_Test\Java2Wsdl_Example\example\META-INF\wsdl\WSExample.wsdl" classpath="C:\J2W_Test\Java2Wsdl_Example" className= "example.WSExample" namespace="http://example" namespaceImpl="http://example" location="http://localhost:9080/example/services/WSExample" style="document" use="literal"> <mapping namespace="http://example" package="example"/> </java2wsdl> <echo message="Complete"/> </target> </project> Code: File buildFile = new File("build.xml"); Project p = new Project(); p.setUserProperty("ant.file", buildFile.getAbsolutePath()); DefaultLogger consoleLogger = new DefaultLogger(); consoleLogger.setErrorPrintStream(System.err); consoleLogger.setOutputPrintStream(System.out); consoleLogger.setMessageOutputLevel(Project.MSG_INFO); p.addBuildListener(consoleLogger); try { p.fireBuildStarted(); p.init(); ProjectHelper helper = ProjectHelper.getProjectHelper(); p.addReference("ant.projectHelper", helper); helper.parse(p, buildFile); p.executeTarget(p.getDefaultTarget()); p.fireBuildFinished(null); } catch (BuildException e) { p.fireBuildFinished(e); } Error: [java2wsdl] java.lang.NoClassDefFoundError: org.eclipse.core.runtime.CoreException [java2wsdl] at java.lang.J9VMInternals.verifyImpl(Native Method) [java2wsdl] at java.lang.J9VMInternals.verify(J9VMInternals.java:68) [java2wsdl] at java.lang.J9VMInternals.initialize(J9VMInternals.java:129) [java2wsdl] at com.ibm.ws.webservices.multiprotocol.discovery.ServiceProviderManager.getDiscoveredServiceProviders(ServiceProviderManager.java:378) [java2wsdl] at com.ibm.ws.webservices.multiprotocol.discovery.ServiceProviderManager.getAllServiceProviders(ServiceProviderManager.java:214) [java2wsdl] at com.ibm.ws.webservices.wsdl.fromJava.Emitter.initPluggableBindings(Emitter.java:2704) [java2wsdl] at com.ibm.ws.webservices.wsdl.fromJava.Emitter.<init>(Emitter.java:389) [java2wsdl] at com.ibm.ws.webservices.tools.ant.Java2WSDL.execute(Java2WSDL.java:122) [java2wsdl] at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:275) [java2wsdl] at org.apache.tools.ant.Task.perform(Task.java:364) [java2wsdl] at org.apache.tools.ant.Target.execute(Target.java:341) [java2wsdl] at org.apache.tools.ant.Target.performTasks(Target.java:369) [java2wsdl] at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1216) [java2wsdl] at org.apache.tools.ant.Project.executeTarget(Project.java:1185) [java2wsdl] at att.ant.RunAnt.main(RunAnt.java:32)

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Google App Engine - SiteMap Creation for a social network

- by spidee

Hi all. I am creating a social tool - I want to allow search engines to pick up "public" user profiles - like twitter and face-book. I have seen all the protocol info at http://www.sitemaps.org and i understand this and how to build such a file - along with an index if i exceed the 50K limit. Where i am struggling is the concept of how i make this run. The site map for my general site pages is simple i can use a tool to create the file - or a script - host the file - submit the file and done. What i then need is a script that will create the site-maps of user profiles. I assume this would be something like: <?xml version="1.0" encoding="UTF-8"?> <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> <url> <loc>http://www.socialsite.com/profile/spidee</loc> <lastmod>2010-5-12</lastmod> <changefreq>???</changefreq> <priority>???</priority> </url> <url> <loc>http://www.socialsite.com/profile/webbsterisback</loc> <lastmod>2010-5-12</lastmod> <changefreq>???</changefreq> <priority>???</priority> </url> </urlset> Ive added some ??? as i don't know how i should set these settings for my profiles based on the following:- When a new profile is created it must be added to a site-map. If the profile is changed or if "certain" properties are changed - then i don't know if i update the entry in the map - or do something else? (updating would be a nightmare!) Some users may change their profile. In terms of relevance to the search engine the only way a google or yahoo search will find the users (for my requirement) profile would be for example by means of [user name] and [location] so once the entry for the profile has been added to the map file the only reason to have the search-bot re-index the profile would be if the user changed their user-name - which they cant. or their location - and or set their settings so that their profile would be "hidden" from search engines. I assume my map creation will need to be dynamic. From what i have said above i would imagine that creating a new profile and possible editing certain properties could mark it as needing adding/updating in the sitemap. Assuming i will have millions of profiles added/being edited how can i manage this in a sensible manner. i know i need a script that can append urls as each profile is created i know the script will prob be a TASK - running at a set freq - perhaps the profiles have a property like "indexed" and the TASK sets them to "true" when the profiles are added to the map. I dont see the best way to store the map - do i store it in the datastore i.e; model=sitemaps properties key_name=sitemap_xml_1 (and for my map sitemap_index_xml) mapxml=blobstore (the raw xml map or ror map) full=boolean (set true when url count is 50) # might need this as a shard will tell us To make this work my thoughts are m cache the current site map structure as "sitemap_xml" keep a shard of url count when my task executes 1. build the xml structure for say the first 100 urls marked "index==false" (how many could u run at a time?) 2. test if the current mcache sitemap is full (shardcounter+10050K) 3.a if the map is near full create a new map entry in models "sitemap_xml_2" - update the map_index file (also stored in my model as "sitemap_index" start a new shard - or reset.2 3.b if the map is not full grab it from mcache 4.append the 100 url xml structure 5.save / m cache the map I can now add a handler using a url map/route like /sitemaps/* Get my * as map name and serve the maps from the blobstore/mache on the fly. Now my question is does this work - is this the right way or a good way to start? Will this handle the situation of making sure the search bots update when a user changes their profile - possibly by setting the change freq correctly? - Do i need a more advance system :( ? or have i re-invented the wheel! I hope this is all clear and make some form of sense :-)

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Custom Section Name Crashing NSFetchedResultsController

- by Mike H.

I have a managed object with a dueDate attribute. Instead of displaying using some ugly date string as the section headers of my UITableView I created a transient attribute called "category" and defined it like so: - (NSString*)category { [self willAccessValueForKey:@"category"]; NSString* categoryName; if ([self isOverdue]) { categoryName = @"Overdue"; } else if ([self.finishedDate != nil]) { categoryName = @"Done"; } else { categoryName = @"In Progress"; } [self didAccessValueForKey:@"category"]; return categoryName; } Here is the NSFetchedResultsController set up: NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Task" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSMutableArray* descriptors = [[NSMutableArray alloc] init]; NSSortDescriptor *dueDateDescriptor = [[NSSortDescriptor alloc] initWithKey:@"dueDate" ascending:YES]; [descriptors addObject:dueDateDescriptor]; [dueDateDescriptor release]; [fetchRequest setSortDescriptors:descriptors]; fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:@"category" cacheName:@"Root"]; The table initially displays fine, showing the unfinished items whose dueDate has not passed in a section titled "In Progress". Now, the user can tap a row in the table view which pushes a new details view onto the navigation stack. In this new view the user can tap a button to indicate that the item is now "Done". Here is the handler for the button (self.task is the managed object): - (void)taskDoneButtonTapped { self.task.finishedDate = [NSDate date]; } As soon as the value of the "finishedDate" attribute changes I'm hit with this exception: 2010-03-18 23:29:52.476 MyApp[1637:207] Serious application error. Exception was caught during Core Data change processing: no section named 'Done' found with userInfo (null) 2010-03-18 23:29:52.477 MyApp[1637:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'no section named 'Done' found' I've managed to figure out that the UITableView that is currently hidden by the new details view is trying to update its rows and sections because the NSFetchedResultsController was notified that something changed in the data set. Here's my table update code (copied from either the Core Data Recipes sample or the CoreBooks sample -- I can't remember which): - (void)controllerWillChangeContent:(NSFetchedResultsController *)controller { [self.tableView beginUpdates]; } - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath { switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeUpdate: [self configureCell:[self.tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath]; break; case NSFetchedResultsChangeMove: [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; // Reloading the section inserts a new row and ensures that titles are updated appropriately. [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:newIndexPath.section] withRowAnimation:UITableViewRowAnimationFade]; break; } } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type { switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; } } - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller { [self.tableView endUpdates]; } I put breakpoints in each of these functions and found that only controllerWillChange is called. The exception is thrown before either controller:didChangeObject:atIndexPath:forChangeType:newIndex or controller:didChangeSection:atIndex:forChangeType are called. At this point I'm stuck. If I change my sectionNameKeyPath to just "dueDate" then everything works fine. I think that's because the dueDate attribute never changes whereas the category will be different when read back after the finishedDate attribute changes. Please help! UPDATE: Here is my UITableViewDataSource code: - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return [[self.fetchedResultsController sections] count]; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section]; return [sectionInfo numberOfObjects]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } [self configureCell:cell atIndexPath:indexPath]; return cell; } - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section]; return [sectionInfo name]; }

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Microsoft launches IE9 preview – No support for XP

- by samsudeen

Microsoft launched the developer preview version of Internet Explorer 9 (IE9) at MIX 10 web conference yesterday.This release is aimed getting the feedback from website designers , developers and other community to make IE9 development better from its previous versions. Microsoft will update the developer preview every eight weeks and the next update is expected on mid of march.So what is new and interesting about IE9 Chakra Chakra (The new scripting engine of IE9) renders the Java script much faster compared to IE8 and other browsers thus improving the performance significantly.According to Microsoft Chakra renders the java script in background with a separate thread parallel to the main engine which is complete new way of rendering from the current browser technologies Standards Microsoft is desperate to make ( surprisingly!!!) IE9 compliance to web standards by supporting the open standards such as Accelerated support for HTML5 video support for new web technologies such as CSS3 and SVG2. ACID3 Test IE9 scores (55/100) in its latest ACID3 test which is much better compared to the IE8 score (22/100) but not even nearer to their rivals Chrome, Opera, and Safari which scores 100/100 in ACID3 testing I am little disappointed over not able to download the developer preview on my XP machine. The early comments looks much positive for IE9.If you want to explore IE9,check the Microsoft Test drive site at Microsoft IE9 Test-drive You can also download the IE9 developer preview at Download Preview Join us on Facebook to read all our stories right inside your Facebook news feed.

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Unable to install Eclipse manually

- by veerendar

I have just started Linux. I have a SBC(Atom processor) on which I have installed Ubuntu 12.04 and now I am trying to install Fortran IDE. For which I have learnt that I need to install OpenJDK first, then Eclipse Juno and at last the Phortran plugin for Eclipse. I have no Internet access so I had follow the below steps for manual installation. First download the eclipse tar.gz package (downloaded: eclipse-parallel-juno-linux-gtk.tar). Then right-click the eclipse tar.gz and choose the extract here option to extract the tar.gz package.You can also use the command line to extract the tar.gz package. # tar xzf eclipse-cpp-juno-linux-gtk.tar.gz Move to /opt/ folder. # mv eclipse /opt/ Use sudo if the above command gives permission denied message. # sudo mv eclipse /opt/ Create a desktop file and place it into /usr/share/applications # sudo gedit /usr/share/applications/eclipse.desktop and copy the following to the eclipse.desktop file [Desktop Entry] Name=Eclipse Type=Application Exec=/opt/eclipse/eclipse Terminal=false Icon=/opt/eclipse/icon.xpm Comment=Integrated Development Environment NoDisplay=false Categories=Development;IDE Name[en]=eclipse.desktop Create a symlink in /usr/local/bin using # cd /usr/local/bin # sudo ln -s /opt/eclipse/eclipse Now its the time to launch eclipse. # /opt/eclipse/eclipse -clean & Now at step 5, when I type the command sudo ln -s /opt/eclipse/eclipse , I get an this error message: ln: Failed to create symbolic link './eclipse': File exists. Please help me in resolving this.

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Turning a board game idea into a browser based, slow paced gameplay

- by guillaume31

Suppose I want to create a strategy game with global mutable state shared between all players (think game board). But unlike a board game, I don't want it to be real time action and/or turn-based. Instead, players should be able to log in at any time of the day and spend a fixed number of action points per day as they wish. As opposed to a few hours, game sessions would run over a few weeks. This is meant to reward good strategy rather than time spent playing (as an alternative, hardcore players could always play multiple games in parallel instead) as well as all kind of issues related to live playing like disconnections and synchronization. The game should remain addictive still have a low time investment footprint for casual players. So far so good, but this still leaves open the question of when to solve actions and when they should be visible. I want to avoid "ninja play" like doing all your moves just a few minutes before daily point reset to take other players by surprise, or people spamming F5 to place a well-timed action which would defeat the whole point of a non real-time game. I thought of a couple of approaches to that : Resolve all events in a single scheduled process running once a day. This basically means a "blind" gameplay where players can take actions but don't see their results immediately. The thing is, I played a similar browser game a few years ago and didn't like the fact that you feel disconnected and powerless until there's that deus ex machina telling you what really happened during all that time. You see the world evolve in large increments of one day, which often doesn't seem like seeing it evolve at all. For actions that have an big impact on the game or on other players (attacks, big achievements), make them visible to everyone immediately but delay their effect by something like 24 hours. Opposing players could be notified when such an event happens, so that they can react to it. Do you have any other ideas how I could go about solving this ? Are there any known approaches in similar existing games ?

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One Exception to Aggregate Them All

- by João Angelo

.NET 4.0 introduced a new type of exception, the AggregateException which as the name implies allows to aggregate several exceptions inside a single throw-able exception instance. It is extensively used in the Task Parallel Library (TPL) and besides representing a simple collection of exceptions can also be used to represent a set of exceptions in a tree-like structure. Besides its InnerExceptions property which is a read-only collection of exceptions, the most relevant members of this new type are the methods Flatten and Handle. The former allows to flatten a tree hierarchy removing the need to recur while working with an aggregate exception. For example, if we would flatten the exception tree illustrated in the previous figure the result would be: The other method, Handle, accepts a predicate that is invoked for each aggregated exception and returns a boolean indicating if each exception is handled or not. If at least one exception goes unhandled then Handle throws a new AggregateException containing only the unhandled exceptions. The following code snippet illustrates this behavior and also another scenario where an aggregate exception proves useful – single threaded batch processing. static void Main() { try { ConvertAllToInt32("10", "x1x", "0", "II"); } catch (AggregateException errors) { // Contained exceptions are all FormatException // so Handle does not thrown any exception errors.Handle(e => e is FormatException); } try { ConvertAllToInt32("1", "1x", null, "-2", "#4"); } catch (AggregateException errors) { // Handle throws a new AggregateException containing // the exceptions for which the predicate failed. // In this case it will contain a single ArgumentNullException errors.Handle(e => e is FormatException); } } private static int[] ConvertAllToInt32(params string[] values) { var errors = new List<Exception>(); var integers = new List<int>(); foreach (var item in values) { try { integers.Add(Int32.Parse(item)); } catch (Exception e) { errors.Add(e); } } if (errors.Count > 0) throw new AggregateException(errors); return integers.ToArray(); }

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How to implement friction in a physics engine based on "Advanced Character Physics"

- by paldepind

I have implemented a physics engine based on the concepts in the classic text Advanced Character Physics by Thomas Jakobsen. Friction is only discussed very briefly in the article and Jakobsen himself notes how "other and better friction models than this could and should be implemented." Generally how could one implement a believable friction model on top of the concepts from the mentioned article? And how could the found friction be translated into rotation on a circle? I do not want this question to be about my specific implementation but about how to combine Jakobsens ideas with a great friction system more generally. But here is a live demo showing the current state of my engine which does not handle friction in any way: http://jsfiddle.net/Z7ECB/embedded/result/ Below is a picture showing and example on how collision detection could work in an engine based in the paper. In the Verlet integration the current and previous position is always stored. Based on these a new position is calculated. In every frame I calculate the distance between the circles and the lines. If this distance is less than a circles radius a collision has occurred and the circle is projected perpendicular out of the offending line according to the size of the overlap (offset on the picture). Velocity is implicit due to Verlet integration so changing position also changes the velocity. What I need to do know is to somehow determine the amount of friction on the circle and move it backwards parallel to the line in order to reduce its speed.

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Queued Loadtest to remove Concurrency issues using Shared Data Service in OpenScript

- by stefan.thieme(at)oracle.com

Queued Processing to remove Concurrency issues in Loadtest ScriptsSome scripts act on information returned by the server, e.g. act on first item in the returned list of pending tasks/actions. This may lead to concurrency issues if the virtual users simulated in a load test scenario are not synchronized in some way.As the load test cases should be carried out in a comparable and straight forward manner simply cancel a transaction in case a collision occurs is clearly not an option. In case you increase the number of virtual users this approach would lead to a high number of requests for the early steps in your transaction (e.g. login, retrieve list of action points, assign an action point to the virtual user) but later steps would be rarely visited successfully or at all, depending on the application logic.A way to tackle this problem is to enqueue the virtual users in a Shared Data Service queue. Only the first virtual user in this queue will be allowed to carry out the critical steps (retrieve list of action points, assign an action point to the virtual user) in your transaction at any one time.Once a virtual user has passed the critical path it will dequeue himself from the head of the queue and continue with his actions. This does theoretically allow virtual users to run in parallel all steps of the transaction which are not part of the critical path.In practice it has been seen this is rarely the case, though it does not allow adding more than N users to perform a transaction without causing delays due to virtual users waiting in the queue. N being the time of the total transaction divided by the sum of the time of all critical steps in this transaction.While this problem can be circumvented by allowing multiple queues to act on individual segments of the list of actions, e.g. per country filter, ends with 0..9 filter, etc.This would require additional handling of these additional queues of slots for the virtual users at the head of the queue in order to maintain the mutually exclusive access to the first element in the list returned by the server at any one time of the load test. Such an improved handling of multiple queues and/or multiple slots is above the subject of this paper.Shared Data Services Pre-RequisitesStart WebLogic Server to host Shared Data ServicesYou will have to make sure that your WebLogic server is installed and started. Shared Data Services may not work if you installed only the minimal installation package for OpenScript. If however you installed the default package including OLT and OTM, you may follow the instructions below to start and verify WebLogic installation.To start the WebLogic Server deployed underneath of Oracle Load Testing and/or Oracle Test Manager you can go to your Start menu, Oracle Application Testing Suite and select the Restart Oracle Application Testing Suite Application Service entry from the Tools submenu.To verify the service has been started you can run the Microsoft Management Console for Services by Selecting Run from the Start Menu and entering services.msc. Look for the entry that reads Oracle Application Testing Suite Application Service, once it has changed it status from Starting to Started you can proceed to verify the login. Please note that this may take several minutes, I would say up to 10 minutes depending on the strength of your CPU horse-power.Verify WebLogic Server user credentialsYou will have to make sure that your WebLogic Server is installed and started. Next open the Oracle WebLogic Server Adminstration Console on http://localhost:8088/console.It may take a while until the application is deployed and started. It may display the following until the Administration Console has been deployed on the fly.Afterwards you can login using the username oats and the password that you selected during install time for your Application Testing Suite administrative purposes.This will bring up the Home page of you WebLogic Server. You have actually verified that you are able to login with these credentials already. However if you want to check the details, navigate to Security Realms, myrealm, Users and Groups tab.Here you could add users to your WebLogic Server which could be used in the later steps. Details on the Groups required for such a custom user to work are exceeding this quick overview and have to be selected with the WebLogic Server Adminstration Guide in mind.Shared Data Services pre-requisites for Load testingOpenScript Preferences have to be set to enable Encryption and provide a default Shared Data Service Connection for Playback.These are pre-requisites you want to use for load testing with Shared Data Services.Please note that the usage of the Connection Parameters (individual directive in the script) for Shared Data Services did not playback reliably in the current version 9.20.0370 of Oracle Load Testing (OLT) and encryption of credentials still seemed to be mandatory as well.General Encryption settingsSelect OpenScript Preferences from the View menu and navigate to the General, Encryption entry in the tree on the left. Select the Encrypt script data option from the list and enter the same password that you used for securing your WebLogic Server Administration Console.Enable global shared data access credentialsSelect OpenScript Preferences from the View menu and navigate to the Playback, Shared Data entry in the tree on the left. Enable the global shared data access credentials and enter the Address, User name and Password determined for your WebLogic Server to host Shared Data Services.Please note, that you may want to replace the localhost in Address with the hosts realname in case you plan to run load tests with Loadtest Agents running on remote systems.Queued Processing of TransactionsEnable Shared Data Services Module in Script PropertiesThe Shared Data Services Module has to be enabled for each Script that wants to employ the Shared Data Service Queue functionality in OpenScript. It can be enabled under the Script menu selecting Script Properties. On the Script Properties Dialog select the Modules section and check Shared Data to enable Shared Data Service Module for your script. Checking the Shared Data Services option will effectively add a line to your script code that adds the sharedData ScriptService to your script class of IteratingVUserScript.@ScriptService oracle.oats.scripting.modules.sharedData.api.SharedDataService sharedData;Record your scriptRecord your script as usual and then add the following things for Queue handling in the Initialize code block, before the first step and after the last step of your critical path and in the Finalize code block.The java code to be added at individual locations is explained in the following sections in full detail.Create a Shared Data Queue in InitializeTo create a Shared Data Queue go to the Java view of your script and enter the following statements to the initialize() code block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);This will create an instantiation of the Shared Data Queue object named queueA which is maintained for upto 120 minutes.If you want to use the code for multiple scripts, make sure to use a different queue name for each one here and in the subsequent steps. You may even consider to use a dynamic queueName based on filters of your result list being concurrently accessed.Prepare a unique id for each IterationIn order to keep track of individual virtual users in our queue we need to create a unique identifier from the virtual user id and the used username right after retrieving the next record from our databank file.getDatabank("Usernames").getNextDatabankRecord();getVariables().set("usernameValue1","VU_{{@vuid}}_{{@iterationnum}}_{{db.Usernames.Username}}_{{@timestamp}}_{{@random(10000)}}");String usernameValue = getVariables().get("usernameValue1");info("Now running virtual user " + usernameValue);As you can see from the above code block, we have set the OpenScript variable usernameValue1 to VU_{{@vuid}}_{{@iterationnum}}_{{db.Usernames.Username}}_{{@timestamp}}_{{@random(10000)}} which is a concatenation of the virtual user id and the iterationnumber for general uniqueness; as well as the username from our databank, the timestamp and a random number for making it further unique and ease spotting of errors.Not all of these fields are actually required to make it really unique, but adding the queue name may also be considered to help troubleshoot multiple queues.The value is then retrieved with the getVariables.get() method call and assigned to the usernameValue String used throughout the script.Please note that moving the getDatabank("Usernames").getNextDatabankRecord(); call to the initialize block was later considered to remove concurrency of multiple virtual users running with the same userid and therefor accessing the same "My Inbox" in step 6. This will effectively give each virtual user a userid from the databank file. Make sure you have enough userids to remove this second hurdle.Enqueue and attend Queue before Critical PathTo maintain the right order of virtual users being allowed into the critical path of the transaction the following pseudo step has to be added in front of the first critical step. In the case of this example this is right in front of the step where we retrieve the list of actions from which we select the first to be assigned to us.beginStep("[0] Waiting in the Queue", 0);{info("Enqueued virtual user " + usernameValue + " at the end of queueA");sharedData.offerLast("queueA", usernameValue);info("Wait until the user is the first in queueA");String queueValue1 = null;do {// we wait for at least 0.7 seconds before we check the head of the// queue. This is the time it takes one user to move through the// critical path, i.e. pass steps [5] Enter country and [6] Assign// to meThread.sleep(700);queueValue1 = (String) sharedData.peekFirst("queueA");info("The first user in queueA is currently: '" + queueValue1 + "' " + queueValue1.getClass() + " length " + queueValue1.length() );info("The current user is '"+ usernameValue + "' " + usernameValue.getClass() + " length " + usernameValue.length() + ": indexOf " + usernameValue.indexOf(queueValue1) + " equals " + usernameValue.equals(queueValue1) );} while ( queueValue1.indexOf(usernameValue) < 0 );info("Now the user is the first in queueA");}endStep();This will enqueue the username to the tail of our Queue. It will will wait for at least 700 milliseconds, the time it takes for one user to exit the critical path and then compare the head of our queue with it's username. This last step will be repeated while the two are not equal (indexOf less than zero). If they are equal the indexOf will yield a value of zero or larger and we will perform the critical steps.Dequeue after Critical PathAfter the virtual user has left the critical path and complete its last step the following code block needs to dequeue the virtual user. In the case of our example this is right after the action has been actually assigned to the virtual user. This will allow the next virtual user to retrieve the list of actions still available and in turn let him make his selection/assignment.info("Get and remove the current user from the head of queueA");String pollValue1 = (String) sharedData.pollFirst("queueA");The current user is removed from the head of the queue. The next one will now be able to match his username against the head of the queue.Clear and Destroy Queue for FinishWhen the script has completed, it should clear and destroy the queue. This code block can be put in the finish block of your script and/or in a separate script in order to clear and remove the queue in case you have spotted an error or want to reset the queue for some reason.info("Clear queueA");sharedData.clearQueue("queueA");info("Destroy queueA");sharedData.destroyQueue("queueA");The users waiting in queueA are cleared and the queue is destroyed. If you have scripts still executing they will be caught in a loop.I found it better to maintain a separate Reset Queue script which contained only the following code in the initialize() block. I use to call this script to make sure the queue is cleared in between multiple Loadtest runs. This script could also even be added as the first in a larger scenario, which would execute it only once at very start of the Loadtest and make sure the queues do not contain any stale entries.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);info("Clear queueA");sharedData.clearQueue("queueA");This will create a Shared Data Queue instance of queueA and clear all entries from this queue.Monitoring QueueWhile creating the scripts it was useful to monitor the contents, i.e. the current first user in the Queue. The following code block will make sure the Shared Data Queue is accessible in the initialize() block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);In the run() block the following code will continuously monitor the first element of the Queue and write an informational message with the current username Value to the Result window.info("Monitor the first users in queueA");String queueValue1 = null;do {queueValue1 = (String) sharedData.peekFirst("queueA");if (queueValue1 != null)info("The first user in queueA is currently: '" + queueValue1 + "' " + queueValue1.getClass() + " length " + queueValue1.length() );} while ( true );This script can be run from OpenScript parallel to a loadtest performed by the Oracle Load Test.However it is not recommend to run this in a production loadtest as the performance impact is unknown. Accessing the Queue's head with the peekFirst() method has been reported with about 2 seconds response time by both OpenScript and OTL. It is advised to log a Service Request to see if this could be lowered in future releases of Application Testing Suite, as the pollFirst() and even offerLast() writing to the tail of the Queue usually returned after an average 0.1 seconds.Debugging QueueWhile debugging the scripts the following was useful to remove single entries from its head, i.e. the current first user in the Queue. The following code block will make sure the Shared Data Queue is accessible in the initialize() block.info("Create queueA with life time of 120 minutes");sharedData.createQueue("queueA", 120);In the run() block the following code will remove the first element of the Queue and write an informational message with the current username Value to the Result window.info("Get and remove the current user from the head of queueA");String pollValue1 = (String) sharedData.pollFirst("queueA");info("The first user in queueA was currently: '" + pollValue1 + "' " + pollValue1.getClass() + " length " + pollValue1.length() );ReferencesOracle Functional Testing OpenScript User's Guide Version 9.20 [E15488-05]Chapter 17 Using the Shared Data Modulehttp://download.oracle.com/otn/nt/apptesting/oats-docs-9.21.0030.zipOracle Fusion Middleware Oracle WebLogic Server Administration Console Online Help 11g Release 1 (10.3.4) [E13952-04]Administration Console Online Help - Manage users and groupshttp://download.oracle.com/docs/cd/E17904_01/apirefs.1111/e13952/taskhelp/security/ManageUsersAndGroups.htm

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Auto-Suggest via ‘Trie’ (Pre-fix Tree)

- by Strenium

Auto-Suggest (Auto-Complete) “thing” has been around for a few years. Here’s my little snippet on the subject. For one of my projects, I had to deal with a non-trivial set of items to be pulled via auto-suggest used by multiple concurrent users. Simple, dumb iteration through a list in local cache or back-end access didn’t quite cut it. Enter a nifty little structure, perfectly suited for storing and matching verbal data: “Trie” (http://tinyurl.com/db56g) also known as a Pre-fix Tree: “Unlike a binary search tree, no node in the tree stores the key associated with that node; instead, its position in the tree defines the key with which it is associated. All the descendants of a node have a common prefix of the string associated with that node, and the root is associated with the empty string. Values are normally not associated with every node, only with leaves and some inner nodes that correspond to keys of interest.” This is a very scalable, performing structure. Though, as usual, something ‘fast’ comes at a cost of ‘size’; fortunately RAM is more plentiful today so I can live with that. I won’t bore you with the detailed algorithmic performance here - Google can do a better job of such. So, here’s C# implementation of all this. Let’s start with individual node: Trie Node /// <summary> /// Contains datum of a single trie node. /// </summary> public class AutoSuggestTrieNode { public char Value { get; set; } /// <summary> /// Gets a value indicating whether this instance is leaf node. /// </summary> /// <value> /// <c>true</c> if this instance is leaf node; otherwise, a prefix node <c>false</c>. /// </value> public bool IsLeafNode { get; private set; } public List<AutoSuggestTrieNode> DescendantNodes { get; private set; } /// <summary> /// Initializes a new instance of the <see cref="AutoSuggestTrieNode"/> class. /// </summary> /// <param name="value">The phonetic value.</param> /// <param name="isLeafNode">if set to <c>true</c> [is leaf node].</param> public AutoSuggestTrieNode(char value = ' ', bool isLeafNode = false) { Value = value; IsLeafNode = isLeafNode; DescendantNodes = new List<AutoSuggestTrieNode>(); } /// <summary> /// Gets the descendants of the pre-fix node, if any. /// </summary> /// <param name="descendantValue">The descendant value.</param> /// <returns></returns> public AutoSuggestTrieNode GetDescendant(char descendantValue) { return DescendantNodes.FirstOrDefault(descendant => descendant.Value == descendantValue); } } Quite self-explanatory, imho. A node is either a “Pre-fix” or a “Leaf” node. “Leaf” contains the full “word”, while the “Pre-fix” nodes act as indices used for matching the results. Ok, now the Trie: Trie Structure /// <summary> /// Contains structure and functionality of an AutoSuggest Trie (Pre-fix Tree) /// </summary> public class AutoSuggestTrie { private readonly AutoSuggestTrieNode _root = new AutoSuggestTrieNode(); /// <summary> /// Adds the word to the trie by breaking it up to pre-fix nodes + leaf node. /// </summary> /// <param name="word">Phonetic value.</param> public void AddWord(string word) { var currentNode = _root; word = word.Trim().ToLower(); for (int i = 0; i < word.Length; i++) { var child = currentNode.GetDescendant(word[i]); if (child == null) /* this character hasn't yet been indexed in the trie */ { var newNode = new AutoSuggestTrieNode(word[i], word.Count() - 1 == i); currentNode.DescendantNodes.Add(newNode); currentNode = newNode; } else currentNode = child; /* this character is already indexed, move down the trie */ } } /// <summary> /// Gets the suggested matches. /// </summary> /// <param name="word">The phonetic search value.</param> /// <returns></returns> public List<string> GetSuggestedMatches(string word) { var currentNode = _root; word = word.Trim().ToLower(); var indexedNodesValues = new StringBuilder(); var resultBag = new ConcurrentBag<string>(); for (int i = 0; i < word.Trim().Length; i++) /* traverse the trie collecting closest indexed parent (parent can't be leaf, obviously) */ { var child = currentNode.GetDescendant(word[i]); if (child == null || word.Count() - 1 == i) break; /* done looking, the rest of the characters aren't indexed in the trie */ indexedNodesValues.Append(word[i]); currentNode = child; } Action<AutoSuggestTrieNode, string> collectAllMatches = null; collectAllMatches = (node, aggregatedValue) => /* traverse the trie collecting matching leafNodes (i.e. "full words") */ { if (node.IsLeafNode) /* full word */ resultBag.Add(aggregatedValue); /* thread-safe write */ Parallel.ForEach(node.DescendantNodes, descendandNode => /* asynchronous recursive traversal */ { collectAllMatches(descendandNode, String.Format("{0}{1}", aggregatedValue, descendandNode.Value)); }); }; collectAllMatches(currentNode, indexedNodesValues.ToString()); return resultBag.OrderBy(o => o).ToList(); } /// <summary> /// Gets the total words (leafs) in the trie. Recursive traversal. /// </summary> public int TotalWords { get { int runningCount = 0; Action<AutoSuggestTrieNode> traverseAllDecendants = null; traverseAllDecendants = n => { runningCount += n.DescendantNodes.Count(o => o.IsLeafNode); n.DescendantNodes.ForEach(traverseAllDecendants); }; traverseAllDecendants(this._root); return runningCount; } } } Matching operations and Inserts involve traversing the nodes before the right “spot” is found. Inserts need be synchronous since ordering of data matters here. However, matching can be done in parallel traversal using recursion (line 64). Here’s sample usage: [TestMethod] public void AutoSuggestTest() { var autoSuggestCache = new AutoSuggestTrie(); var testInput = @"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero. Sed cursus ante dapibus diam. Sed nisi. Nulla quis sem at nibh elementum imperdiet. Duis sagittis ipsum. Praesent mauris. Fusce nec tellus sed augue semper porta. Mauris massa. Vestibulum lacinia arcu eget nulla. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Curabitur sodales ligula in libero. Sed dignissim lacinia nunc. Curabitur tortor. Pellentesque nibh. Aenean quam. In scelerisque sem at dolor. Maecenas mattis. Sed convallis tristique sem. Proin ut ligula vel nunc egestas porttitor. Morbi lectus risus, iaculis vel, suscipit quis, luctus non, massa. Fusce ac turpis quis ligula lacinia aliquet. Mauris ipsum. Nulla metus metus, ullamcorper vel, tincidunt sed, euismod in, nibh. Quisque volutpat condimentum velit. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Nam nec ante. Sed lacinia, urna non tincidunt mattis, tortor neque adipiscing diam, a cursus ipsum ante quis turpis. Nulla facilisi. Ut fringilla. Suspendisse potenti. Nunc feugiat mi a tellus consequat imperdiet. Vestibulum sapien. Proin quam. Etiam ultrices. Suspendisse in justo eu magna luctus suscipit. Sed lectus. Integer euismod lacus luctus magna. Quisque cursus, metus vitae pharetra auctor, sem massa mattis sem, at interdum magna augue eget diam. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Morbi lacinia molestie dui. Praesent blandit dolor. Sed non quam. In vel mi sit amet augue congue elementum. Morbi in ipsum sit amet pede facilisis laoreet. Donec lacus nunc, viverra nec."; testInput.Split(' ').ToList().ForEach(word => autoSuggestCache.AddWord(word)); var testMatches = autoSuggestCache.GetSuggestedMatches("le"); } ..and the result: That’s it!

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Windows HPC Server links

I've already described how to setup a Windows HPC Server for development. Before you dive into developing for the cluster, if you are new to this it is probably a good idea to learn the basics by reading some overview material. Below is a list of links.Direct Links to Windows HPC content1. Windows HPC Server 2008 Overview Datasheet (4 page pdf).2. Windows HPC Server 2008 Technical Overview (32 page doc).3. Windows HPC Server 2008 Getting Started Guide (26 page doc) which actually is available online as part of the TechNet technical library section on Windows HPC Server 2008, which includes much more useful data.4. Windows HPC Server 2008 Job Scheduler (38 page doc).5. Windows HPC Server 2008 Job Templates (56 page doc).6. Developing for the Windows HPC Server 2008 Platform (16 page doc or pdf version).Windows HPC sites7. Windows HPC Forums.8. HPC Developer Resources.9. Windows HPC Server 2008 Resource Kit - Developer.10. Windows HPC Server 2008 - TechNet.11. The Windows HPC Team Blog.HPC Course12. High-Performance Computing Fundamentals Course (pluralisight)13. Classic HPC Development using Visual C++ (course slides and materials in a ZIP). Author's blog post.14. From sequential to parallel code (course slides and materials in a ZIP). Author's blog post. Next time I will post resources specific to the most popular programming models for the cluster today: MPI and Cluster SOA - until then, happy reading! Comments about this post welcome at the original blog.

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Attend my Fusion sessions

- by Daniel Moth

The inaugural Fusion conference was 1 year ago in June 2011 and I was there doing a demo in the keynote, and also presenting a breakout session. If you look at the abstract and title for that session you won't see the term "C++ AMP" in there because the technology wasn't announced and we didn't want to spill the beans ahead of the keynote, where the technology was announced. It was only an announcement, we did not give any bits out, and in fact the first bits came three months later in September 2011 with the Beta following in February 2012. So it really feels great 1 year later, to be back at Fusion presenting two sessions on C++ AMP, demonstrating our progress from that announcement, to the Visual Studio 2012 Release Candidate that came out last week. If you are attending Fusion (in person or virtually later), be sure to watch my two-part session. Part 1 is PT-3601 on Tuesday 4pm and part 2 is PT-3602 on Wednesday 4pm. Here is the shared abstract for both parts: Harnessing GPU Compute with C++ AMP C++ AMP is an open specification for taking advantage of accelerators like the GPU. In this session we will explore the C++ AMP implementation in Microsoft Visual Studio 2012. After a quick overview of the technology understanding its goals and its differentiation compared with other approaches, we will dive into the programming model and its modern C++ API. This is a code heavy, interactive, two-part session, where every part of the library will be explained. Demos will include showing off the richest parallel and GPU debugging story on the market, in the upcoming Visual Studio release. See you there! Comments about this post by Daniel Moth welcome at the original blog.

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Optimize Images Using the ASP.NET Sprite and Image Optimization Framework

The HTML markup of a web page includes the page's textual content, semantic and styling information, and, typically, several references to external resources. External resources are content that is part of web page, but are separate from the web page's markup - things like images, style sheets, script files, Flash videos, and so on. When a browser requests a web page it starts by downloading its HTML. Next, it scans the downloaded HTML for external resources and starts downloading those. A page with many external resources usually takes longer to completely load than a page with fewer external resources because there is an overhead associated with downloading each external resource. For starters, each external resource requires the browser to make an HTTP request to retrieve the resource. What's more, browsers have a limit as to how many HTTP requests they will make in parallel. For these reasons, a common technique for improving a page's load time is to consolidate external resources in a way to reduce the number of HTTP requests that must be made by the browser to load the page in its entirety. This article examines the free and open-source ASP.NET Sprite and Image Optimization Framework, which is a project developed by Microsoft for improving a web page's load time by consolidating images into a sprite or by using inline, base-64 encoded images. In a nutshell, this framework makes it easy to implement practices that will improve the load time for a web page that displays several images. Read on to learn more! Read More >

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BUILD apps that use C++ AMP

- by Daniel Moth

If you are a developer on the Microsoft platform, you are hopefully attending (live or virtually) the sessions of the BUILD conference, aka //build/ in Anaheim, CA. The conference sold out not long after it opened registration, and it achieved that without sharing *any* session details nor a meaningful agenda up until after the keynote today – impressive! I am speaking at BUILD and hope you'll catch my talk at 9am on Friday (the last day of the conference) at Marriott Elite 2 Ballroom. Session details follow. 802 - Taming GPU compute with C++ AMP Developers today inject parallelism into their compute-intensive applications in order to take advantage of multi-core CPU hardware. Beyond CPUs, however, compute accelerators such as general-purpose GPUs can provide orders of magnitude speed-ups for data parallel algorithms. How can you as a C++ developer fully utilize this heterogeneous hardware from your Visual Studio environment? How can you benefit from this tremendous performance boost in your Visual C++ solutions without sacrificing developer productivity? The answers will be presented in this session about C++ Accelerated Massive Parallelism. I'll be covering a lot of the material I've been recently blogging about on my blog that you are reading, which I have also indexed over on our team blog under the title: "C++ AMP in a nutshell". Comments about this post by Daniel Moth welcome at the original blog.

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2D character controller in unity (trying to get old-school platformers back)

- by Notbad

This days I'm trying to create a 2D character controller with unity (using phisics). I'm fairly new to physic engines and it is really hard to get the control feel I'm looking for. I would be really happy if anyone could suggest solution for a problem I'm finding: This is my FixedUpdate right now: public void FixedUpdate() { Vector3 v=new Vector3(0,-10000*Time.fixedDeltaTime,0); _body.AddForce(v); v.y=0; if(state(MovementState.Left)) { v.x=-_walkSpeed*Time.fixedDeltaTime+v.x; if(Mathf.Abs(v.x)>_maxWalkSpeed) v.x=-_maxWalkSpeed; } else if(state(MovementState.Right)) { v.x= _walkSpeed*Time.fixedDeltaTime+v.x; if(Mathf.Abs(v.x)>_maxWalkSpeed) v.x=_maxWalkSpeed; } _body.velocity=v; Debug.Log("Velocity: "+_body.velocity); } I'm trying here to just move the rigid body applying a gravity and a linear force for left and right. I have setup a physic material that makes no bouncing and 0 friction when moving and 1 friction with stand still. The main problem is that I have colliders with slopes and the velocity changes from going up (slower) , going down the slope (faster) and walk on a straight collider (normal). How could this be fixed? As you see I'm applying allways same velocity for x axis. For the player I have it setup with a sphere at feet position that is the rigidbody I'm applying forces to. Any other tip that could make my life easier with this are welcomed :). P.D. While coming home I have noticed I could solve this applying a constant force parallel to the surface the player is walking, but don't know if it is best method.

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Google CDN or Akamai

- by AlienWebguy

We combine and minify our JS with Minify - the combined JS is then cached on Akamai. I'm suggesting to my supervisor that we put JQuery and JQueryUI on Google CDN and take it out of our combined JS. The benefits I see are parallel downloads, significantly smaller Akamai cache hit, and the high potential the user will have JQuery from Google CDN cached in his/her browser when he/she visits our site so no download will be required at all. I also pointed out how pointing to the major version CDN URL //ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js will eliminate the need for us to micro-manage our JQuery version control, and that if a new release introduces a bug, we simply point the CDN URL to a stable minor version of our choice until the issue is resolved. My supervisor disagrees and thinks keeping it on Akamai is the way to go. Any insight as to which is going to be faster here? I looked for some benchmarks and references online but they are either out-dated or merely talk about Google wanting to acquire Akamai. EDIT: Some further research has pointed me to an article mentioning how 'latest version' CDN URL's use short expires headers so it might be more optimal to use /jquery/1.7/. I'm fine with this - the general question still remains.

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Async & Await in C# with Xamarin

- by Wallym

One of the great things about the .NET Framework is that Microsoft has worked long and hard to improve many features. Since the initial release of .NET 1.0, there has been support for threading via .NET threads as well as an application-level threadpool. This provided a great starting point when compared to Visual Basic 6 and classic ASP programming. The release of.NET 4 brought significant improvements in the area of threading, asynchronous operations and parallel operations. While the improvements made working with asynchronous operations easier, new problems were introduced, since many of these operations work based on callbacks. For example: How should a developer handle error checking? The program flow tends to be non-linear. Fixing bugs can be problematic. It is hard for a developer to get an understanding of what is happening within an application. The release of .NET 4.5 (and C# 5.0), in the fall of 2012, was a blockbuster update with regards to asynchronous operations and threads. Microsoft has added C# language keywords to take this non-linear callback-based program flow and turn it into a much more linear flow. Recently, Xamarin has updated Xamarin.Android and Xamarin.iOS to support async. This article will look at how Xamarin has implemented the .NET 4.5/C# 5 support into their Xamarin.iOS and Xamarin.Android productions. There are three general areas that I'll focus on: A general look at the asynchronous support in Xamarin's mobile products. This includes async, await, and the implications that this has for cross-platform code. The new HttpClient class that is provided in .NET 4.5/Mono 3.2. Xamarin's extensions for asynchronous operations for Android and iOS. FYI: Be aware that sometimes the OpenWeatherMap API breaks, for no reason. I found this out after I shipped the article in.

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Bit by bit comparison of using Java or Python for unit testing frameworks and Selenium

- by Anirudh

Currently we are in the process of finalizing which language out of Java, Python should be used for Automation using selenium webdriver and a suitable unit testing frameworks. I have made use of Junit, TestNG and webdriver while using with Java and have designed frameworks without much fuss before. I am new to python though I came across pyhton's unit testing frameworks like unittest, pyunit, nose e.t.c but I have doubts if they would be as successful as testNG or Java. I would like to analyze point by point when used with selenium webdriver as below: 1)I have read that as Python is an interpreted language hence it's execution is slower, so say if I have to run 1000 test cases which take about 6 hours to run in Java, would python take considerably longer time for the same test cases like 8 hours? 2)Can the Python unit testing framework be as flexible as a Java unit testing framework like testNG in terms or Grouping the tests, parallel execution, skipping test. e.t.c 3)Also one point that I think of is that Python with selenium webdriver doeasn't have as big or learned community as we have for Java with webdriver, say if I run into trouble with something I am more likely to find an answer for Java as compared to python? 4)Somewhat related to point 3, is it safe to rely on tools, plugins or even webderiver's python's binding as a continuously well maintained? 5)One major drawback as I see while using python's unit testing framework is lack of boilerplate code or libraries for nicely illustrative HTML reports preferably historical reports with Pie charts, bar graphs and timelines as we have in case of Java like Allure, TestNG's default reports, reportNG or Junit reports with the help of ANT as shown below Allure Reports Junit Historical reports Also I would like to emphasize on the fact if there is a way for one to write the framework in java and make libraries or utilities according to out application in webdriver which can easily be called or integrated in with python code or modules? That would actually solve the problem for us as the client would be able to use the code we write in Java and make use of the same or call it from their python modules?

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Big Data for Retail

- by David Dorf

Right up there with mobile, social, and cloud is the term "big data," which seems to be popping up lots in the press these days. Companies like Google, Yahoo, and Facebook have popularized a new class of data technologies meant to solve the problem of processing large amounts of data quickly. I first mentioned this in a posting back in March 2009. Put simply, big data implies datasets so large they can't normally be processed using a standard transactional database. The term "noSQL" is often used in this context as well. Actually, using parallel processing within the Oracle database combined with Exadata can achieve impressive results. Look for more from Oracle at OpenWorld as hinted by Jean-Pierre Dijcks. McKinsey recently released a report on big data in which retail was specifically mentioned as an industry that can benefit from the new technologies. I won't rehash that report because my friend Rama already did such a good job in his posting, Impact of "Big Data" on Retail. The presentation below does a pretty good job of framing the problem, although it doesn't really get into the available technologies (e.g. Exadata, Hadoop, Cassandra, etc.) and isn't retail specific. Determine the Right Analytic Database: A Survey of New Data Technologies So when a retailer asks me about big data, here's what I say: Big data refers to a set of technologies for processing large volumes of structured and unstructured data. Imagine collecting everything uttered by your customers on Facebook and Twitter and combining it with all the data you can find about the products you sell (e.g. reviews, images, demonstration videos), including competitive data. Assuming you could process all that data, you could then personalize offers to specific customers based on their tastes, ensure prices are competitive, and implement better local assortments. It's really not that far off.

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How to Avoid Your Next 12-Month Science Project

- by constant

While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack. After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades? On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea. Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company. Engineering Systems is Hard Work! The backbone of Exalogic is its InfiniBand network: 4 times better bandwidth than even 10 Gigabit Ethernet, and only about a tenth of its latency. What a potential for increased scalability and throughput across the middleware and database layers! But InfiniBand is a beast that needs to be tamed: It is true that Exalogic uses a standard, open-source Open Fabrics Enterprise Distribution (OFED) InfiniBand driver stack. Unfortunately, this software has been developed by the HPC community with fastest speed in mind (which is good) but, despite the name, not many other enterprise-class requirements are included (which is less good). Here are some of the improvements that Oracle's InfiniBand development team had to add to the OFED stack to make it enterprise-ready, simply because typical HPC users didn't have the need to implement them: More than 100 bug fixes in the pieces that were not related to the Message Passing Interface Protocol (MPI), which is the protocol that HPC users use most of the time, but which is less useful in the enterprise. Performance optimizations and tuning across the whole IB stack: From Switches, Host Channel Adapters (HCAs) and drivers to low-level protocols, middleware and applications. Yes, even the standard HPC IB stack could be improved in terms of performance. Ethernet over IB (EoIB): Exalogic uses InfiniBand internally to reach high performance, but it needs to play nicely with datacenters around it. That's why Oracle added Ethernet over InfiniBand technology to it that allows for creating many virtual 10GBE adapters inside Exalogic's nodes that are aggregated and connected to Exalogic's IB gateway switches. While this is an open standard, it's up to the vendor to implement it. In this case, Oracle integrated the EoIB stack with Oracle's own IB to 10GBE gateway switches, and made it fully virtualized from the beginning. This means that Exalogic customers can completely rewire their server infrastructure inside the rack without having to physically pull or plug a single cable - a must-have for every cloud deployment. Anybody who wants to match this level of integration would need to add an InfiniBand switch development team to their project. Or just buy Oracle's gateway switches, which are conveniently shipped with a whole server infrastructure attached! IPv6 support for InfiniBand's Sockets Direct Protocol (SDP), Reliable Datagram Sockets (RDS), TCP/IP over IB (IPoIB) and EoIB protocols. Because no IPv6 = not very enterprise-class. HA capability for SDP. High Availability is not a big requirement for HPC, but for enterprise-class application servers it is. Every node in Exalogic's InfiniBand network is connected twice for redundancy. If any cable or port or HCA fails, there's always a replacement link ready to take over. This requires extra magic at the protocol level to work. So in addition to Weblogic's failover capabilities, Oracle implemented IB automatic path migration at the SDP level to avoid unnecessary failover operations at the middleware level. Security, for example spoof-protection. Another feature that is less important for traditional users of InfiniBand, but very important for enterprise customers. InfiniBand Partitioning and Quality-of-Service (QoS): One of the first questions we get from customers about Exalogic is: “How can we implement multi-tenancy?” The answer is to partition your IB network, which effectively creates many networks that work independently and that are protected at the lowest networking layer possible. In addition to that, QoS allows administrators to prioritize traffic flow in multi-tenancy environments so they can keep their service levels where it matters most. Resilient IB Fabric Management: InfiniBand is a self-managing network, so a lot of the magic lies in coming up with the right topology and in teaching the subnet manager how to properly discover and manage the network. Oracle's Infiniband switches come with pre-integrated, highly available fabric management with seamless integration into Oracle Enterprise Manager Ops Center. In short: Oracle elevated the OFED InfiniBand stack into an enterprise-class networking infrastructure. Many years and multiple teams of manpower went into the above improvements - this is something you can only get from Oracle, because no other InfiniBand vendor can give you these features across the whole stack! Exabus: Because it's not About the Size of Your Network, it's How You Use it! So let's assume that you somehow were able to get your hands on an enterprise-class IB driver stack. Or maybe you don't care and are just happy with the standard OFED one? Anyway, the next step is to actually leverage that InfiniBand performance. Here are the choices: Use traditional TCP/IP on top of the InfiniBand stack, Develop your own integration between your middleware and the lower-level (but faster) InfiniBand protocols. While more bandwidth is always a good thing, it's actually the low latency that enables superior performance for your applications when running on any networking infrastructure: The lower the latency, the faster the response travels through the network and the more transactions you can close per second. The reason why InfiniBand is such a low latency technology is that it gets rid of most if not all of your traditional networking protocol stack: Data is literally beamed from one region of RAM in one server into another region of RAM in another server with no kernel/drivers/UDP/TCP or other networking stack overhead involved! Which makes option 1 a no-go: Adding TCP/IP on top of InfiniBand is like adding training wheels to your racing bike. It may be ok in the beginning and for development, but it's not quite the performance IB was meant to deliver. Which only leaves option 2: Integrating your middleware with fast, low-level InfiniBand protocols. And this is what Exalogic's "Exabus" technology is all about. Here are a few Exabus features that help applications leverage the performance of InfiniBand in Exalogic: RDMA and SDP integration at the JDBC driver level (SDP), for Oracle Weblogic (SDP), Oracle Coherence (RDMA), Oracle Tuxedo (RDMA) and the new Oracle Traffic Director (RDMA) on Exalogic. Using these protocols, middleware can communicate a lot faster with each other and the Oracle database than by using standard networking protocols, Seamless Integration of Ethernet over InfiniBand from Exalogic's Gateway switches into the OS, Oracle Weblogic optimizations for handling massive amounts of parallel transactions. Because if you have an 8-lane Autobahn, you also need to improve your ramps so you can feed it with many cars in parallel. Integration of Weblogic with Oracle Exadata for faster performance, optimized session management and failover. As you see, “Exabus” is Oracle's word for describing all the InfiniBand enhancements Oracle put into Exalogic: OFED stack enhancements, protocols for faster IB access, and InfiniBand support and optimizations at the virtualization and middleware level. All working together to deliver the full potential of InfiniBand performance. Who else has 100% control over their middleware so they can develop their own low-level protocol integration with InfiniBand? Even if you take an open source approach, you're looking at years of development work to create, test and support a whole new networking technology in your middleware! The Extras: Less Hassle, More Productivity, Faster Time to Market And then there are the other advantages of Engineered Systems that are true for Exalogic the same as they are for every other Engineered System: One simple purchasing process: No headaches due to endless RFPs and no “Will X work with Y?” uncertainties. Everything has been engineered together: All kinds of bugs and problems have been already fixed at the design level that would have only manifested themselves after you have built the system from scratch. Everything is built, tested and integrated at the factory level . Less integration pain for you, faster time to market. Every Exalogic machine world-wide is identical to Oracle's own machines in the lab: Instant replication of any problems you may encounter, faster time to resolution. Simplified patching, management and operations. One throat to choke: Imagine finger-pointing hell for systems that have been put together using several different vendors. Oracle's Engineered Systems have a single phone number that customers can call to get their problems solved. For more business-centric values, read The Business Value of Engineered Systems. Conclusion: Buy Exalogic, or get ready for a 6-12 Month Science Project And here's the reason why it's not easy to "build your own Exalogic": There's a lot of work required to make such a system fly. In fact, anybody who is starting to "just put together a bunch of servers and an InfiniBand network" is really looking at a 6-12 month science project. And the outcome is likely to not be very enterprise-class. And it won't have Exalogic's performance either. Because building an Engineered System is literally rocket science: It takes a lot of time, effort, resources and many iterations of design/test/analyze/fix to build such a system. That's why InfiniBand has been reserved for HPC scientists for such a long time. And only Oracle can bring the power of InfiniBand in an enterprise-class, ready-to use, pre-integrated version to customers, without the develop/integrate/support pain. For more details, check the new Exalogic overview white paper which was updated only recently. P.S.: Thanks to my colleagues Ola, Paul, Don and Andy for helping me put together this article! var flattr_uid = '26528'; var flattr_tle = 'How to Avoid Your Next 12-Month Science Project'; var flattr_dsc = 'While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack.After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades?On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea.Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company.'; var flattr_tag = 'Engineered Systems,Engineered Systems,Infiniband,Integration,latency,Oracle,performance'; var flattr_cat = 'text'; var flattr_url = 'http://constantin.glez.de/blog/2012/04/how-avoid-your-next-12-month-science-project'; var flattr_lng = 'en_GB'

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Scheduling of jobs in the presence of constraints in Java

- by Asgard

I want to know how to implement a solution to this problem: A task is performed by running, by more people, some basic jobs with known duration in time units (days, months, etc..). The execution of the jobs could lead to the existence of time constraints: a job, for example, can not start if it is not over another (or others) and so on. I want to design and build an application to check the correctness of jobs activities and to propose a schedule of jobs, if any, which is respectful of the constraints. Input must provide the jobs and associated constraints. The expected output is the scheduling of jobs. The specification of an elementary job consists of the pair <jobs-id, duration> A constraint is expressed by means of a quintuple of the type <S/E, id-job1, B/A, S/E, id-job2> the beginning (S) or the end (E) of a jobs Id-job1, must take place before (B) / after (A) of the beginning (S) / end (E) of the Id-job2. If there are no dependencies between some jobs, then jobs can be done before, in parallel. As a simple example, consider the input: jobs jobs(0, 3) jobs(1, 4) jobs(2, 5) jobs(3, 3) jobs(4, 3) constraints constraints(S, 1, A, E, 0) constraints(S, 4, A, E, 2) Possible output: t 0 1 2 3 4 0 * - * * - 1 * - * * - 2 * - * * - 3 * - * * - 4 - * * - - 5 - * * - - 6 - * - - * 7 - * - - * 8 - * - - * 9 - - - - * How to code an efficient java scheduler(avoiding the intense backtracking if is possible) to manage the jobs with these constraints, as described??? I have seen a discussion on a thread in a forum where an user seems has solved the problem easily, but He haven't given enough details to the users to compile a working project(I'm noob), and I'm interested to know an effective implementation of the solution (without using external libraries). If someone help me, I'll give to him a very good feedback ;)

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