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  • Windows 8 Remote Desktop only allows one user at a time?

    - by segmentation fault
    I tried connecting to Windows 8 using its built-in Remote Desktop feature, but for some inexplicable reason, it requires that no users are logged in on the target machine before a remote user can log in. This has never been a problem with rdesktop on Unixen; I could rdesktop from as many machines as I wanted and any logged-in users would never notice a thing. What's the problem with Windows? Any way to allow concurrent local and remote logins to a Windows 8 machine without hacks or cracks? The "guides" on how to do this that show up in the Google results all suggest replacing a system DLL with a hacked one, but that's not acceptable.

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  • Terminal Server 2003 Login Issue - Insufficient system resources exist to complete the requested ser

    - by LP
    Afternoon. We have three identical terminal servers running Windows Server 2003 SP2, on these servers there are about 250 concurrent users logged on. We're running Roaming Profiles on a central server running Active Directory which cache the profiles locally on each terminal server as well. When one, and just that one, user tries to login she gets this error message (roughly translated from Swedish): "You could not be logged in becouse your principle could not be registered. Check that you're connected to the network or ask your administrator Insufficient system resources exist to complete the requested service." Anyone have an idea about this? I'm stumped ... Best Regards LP

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  • Allow Internet Access with Default Gateway on Windows 7 VPN Server

    - by Hakoda
    I have a Windows 7 box at home (which I'll refer to as Home-VPN) that runs a simple PPTP VPN server. I have a range of 2 IP address (192.168.1.10-192.168.1.11) to give out, although the server is only able to give out one concurrent connection. Ports 1723 & 47 are correctly forwarded to the server. IPv6 is disabled on both Home-VPN and the client. I setup Home-VPN just like this Youtube video: http://www.youtube.com/watch?v=1s5JxMG06L4 I can connect to it just fine but I can't access the Internet when connected to Home-VPN, all outside web servers (eg. google.com, mozilla.org, apple.com) are unreachable. I know I can uncheck "Use Default Gateway on Remote Servers" on the client side under IPv4 settings but that will route all my traffic through my current connection, rather than through the VPN, defeating the purpose of said VPN. Any ideas on how I can fix this?

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  • Server Sizing Methodology

    - by adbrpc
    Our development environment consist of JBoss 5.0.1 DB Server, SQL Server 2008, Oracle IDM. Hardware is Win 2008 32 bit, 4GB RAM. We have reached stage where our environment can not handle application resulting in JBoss shut down throwing out of memory errors and CPU reaching to 90% usage. I am looking methodology to calculate correct server sizing where I input TPS, max number of concurrent users, max CPU utilization etc.. to give me number of servers, RAM size, number of cores. I am expecting application to grow 10% annually. Load Balancer and Failover should also be taken in account while sizing.

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  • Open table cache in MySQL

    - by vvanscherpenseel
    I have my open table cache set to 1800 and I have a total of 1112 tables. MySQL Tuning Primer reports that 100% of my table cache is used yet my table cache hit rate is 5%. I understand that this happens due to concurrent connections all opening tables. I think I should raise the cache limit. I understand that the cache size is limited by the file descriptor limit of my operating system, but are there any other practical limitations I should be aware of? Searching Google or this very website yields mostly posts explaining the connection-factor or come up with indecisive answers. My question: can I safely increase the open table cache limit? Is there a maximum?

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  • Does Virtual Machines with Microsoft server 2003 with Host operating system Vista Home Premium suffer from Vista contraints?

    - by mokokamello
    Experts ! i have a machine with vista home premium and i wanted to share a folder with my colleagues unfortunately i vista allow only 10 concurrent connections to a shared folder one of my colleagues advised me to install a Virtual machine with windows server 2003 so that i will be able to share the folder with more than 1000 user. another colleague stated that the kind of virtual server does not matter, what matters is the host OS, in this case vista. so the folder will be shared by no more than 10 users. my Question is Does Virtual Machines with Microsoft server 2003 with Host operating system Vista Home Premium suffer from Vista contraints?

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  • What are the pros & cons of these MySQL engines for OLTP -- XtraDB, PBXT, or TokuDB?

    - by Continuation
    I'm working on a social website with an approximate read/write split of 90/10. Trying to decide on a MySQL engine. The ones I'm interested in are: XtraDB PBXT TokuDB What are the pros and cons of them for my use case? A few specific questions: PBXT uses log-based structure that avoids double-writes. It sounds very elegant, but the benchmark I've seen doesn't show any/much advantages over XtraDB. Do you have any experience with PBXT/XtraDB you can share? TokuDB sounds VERY interesting. But all the benchmarks I've seen are about single-threaded bulk inserts - inserting 100M rows for example. that's not very relevant for OLTP. What about its performance with large number of concurrent threads writing and reading at the same time? Anyone has tried that?

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  • Webserver - Memory-bound or CPU-bound? [closed]

    - by JJP
    Possible Duplicate: How do you do Load Testing and Capacity Planning for Web Sites I'm installing a social network using Zend Framework & MySql, with lots of plugins & queries. I want Webserver & Sql server on one box. I'm trying to choose between two machines (on hetzner.de): A) intel i7-2600 3.4 GHz 16 GB DDR3 RAM B) intel i7-920 2.6 GHz 24 GB DDR3 RAM B has 50% more RAM but 30% slower clock speed. Q is: is it obvious where the bottleneck will be? Would I ever need 24GB of RAM, even with lots of concurrent users?

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  • MSSQL 2005 Snapshot Agent Uses 100% CPU

    - by matth1jd
    When setting up a new subscription to a publication (transactional replication) from 64-bit SQL Server 2005 to 64-bit SQL Server 2005 the Snapshot Agent on the publisher consumes 100% of the CPU. I am using SSMS to create the new subscription. My initial impression is that this could be from row locking occurring during the generation of the snapshot but I have read that a concurrent snapshot is generated by default in SQL Server 2005, and that row locking shouldn't be a concern. As this is a production server I would like to be able to initialize replication without bringing the box to it's knees. Any suggestions would be helpful and appreciated.

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  • How is Javascript parsed/executed in a web browser exactly?

    - by ededed
    For example when I access web server likely Javascript will execute. From there on, how will the browser parse the Javascript, or "execute" the functions, the memory used, etc. How will the browser "handle" all of that? Does it act like a compilation lexer in that it passes line by line and generates object code, or does it use the DOM, and other specifications to handle memory, etc. Also, in terms of updating the page, and alterior concurrent executions as well, such as Flash, HTML, Java, etc. Point be simplified, how does the browser handle the scripts, the memory, and the logic on page from a javascript file?

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  • kSOAP2 and SOAPAction on Android

    - by Matze
    Hi everyone, I am trying to access a Webservice with kSOAP2 on an Android Phone. I think the connection is being established, but the server won't answer my request since I'm not providing a SOAP Action Header which seems to be required in SOAP Version 1.1(please correct me if I'm wrong here) which I have to use since the server does not support Version 1.2 . The concrete Faultcode which is returning in the request looks like this: faultactor null faultcode "S:Server" (id=830064966432) faultstring "String index out of range: -11" (id=830064966736) The errorcode which is generated on the server (I'm running it on a localhost) looks like this: 4.05.2010 20:20:29 com.sun.xml.internal.ws.transport.http.HttpAdapter fixQuotesAroundSoapAction WARNUNG: Received WS-I BP non-conformant Unquoted SoapAction HTTP header: http://server.contextlayer.bscwi.de/createContext 24.05.2010 20:20:29 com.sun.xml.internal.ws.server.sei.EndpointMethodHandler invoke SCHWERWIEGEND: String index out of range: -11 java.lang.StringIndexOutOfBoundsException: String index out of range: -11 at java.lang.String.substring(Unknown Source) at de.bscwi.contextlayer.xml.XmlValidator.isValid(XmlValidator.java:41) at de.bscwi.contextlayer.server.ContextWS.createContext(ContextWS.java:45) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at com.sun.xml.internal.ws.api.server.InstanceResolver$1.invoke(Unknown Source) at com.sun.xml.internal.ws.server.InvokerTube$2.invoke(Unknown Source) at com.sun.xml.internal.ws.server.sei.EndpointMethodHandler.invoke(Unknown Source) at com.sun.xml.internal.ws.server.sei.SEIInvokerTube.processRequest(Unknown Source) at com.sun.xml.internal.ws.api.pipe.Fiber.__doRun(Unknown Source) at com.sun.xml.internal.ws.api.pipe.Fiber._doRun(Unknown Source) at com.sun.xml.internal.ws.api.pipe.Fiber.doRun(Unknown Source) at com.sun.xml.internal.ws.api.pipe.Fiber.runSync(Unknown Source) at com.sun.xml.internal.ws.server.WSEndpointImpl$2.process(Unknown Source) at com.sun.xml.internal.ws.transport.http.HttpAdapter$HttpToolkit.handle(Unknown Source) at com.sun.xml.internal.ws.transport.http.HttpAdapter.handle(Unknown Source) at com.sun.xml.internal.ws.transport.http.server.WSHttpHandler.handleExchange(Unknown Source) at com.sun.xml.internal.ws.transport.http.server.WSHttpHandler.handle(Unknown Source) at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source) at sun.net.httpserver.AuthFilter.doFilter(Unknown Source) at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source) at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(Unknown Source) at com.sun.net.httpserver.Filter$Chain.doFilter(Unknown Source) at sun.net.httpserver.ServerImpl$Exchange.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) The relevant part of the WSDL (at least that's what I'm thinking) looks like this: <operation name="createContext"> <soap:operation soapAction=""/> - <input> <soap:body use="literal" namespace="http://server.contextlayer.bscwi.de/"/> </input> - <output> <soap:body use="literal" namespace="http://server.contextlayer.bscwi.de/"/> </output> </operation> In my code I'm adding a Header, but it seems like I'm doing it wrong: private static final String SOAP_ACTION = ""; //... SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope (SoapEnvelope.VER11); soapEnvelope.setOutputSoapObject(Request); AndroidHttpTransport aht = new AndroidHttpTransport (URL); //... aht.call(SOAP_ACTION, soapEnvelope); SoapPrimitive resultString = (SoapPrimitive) soapEnvelope.getResponse(); Any advice would be great since I'm running out of ideas.. Thanks folks!

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  • Example map-reduce oozie program not working on CDH 4.5

    - by user2002748
    I am using Hadoop (CDH 4.5) on my mac since some time now, and do run map reduce jobs regularly. I installed oozie recently (again, CDH4.5) following instructions at: http://archive.cloudera.com/cdh4/cdh/4/oozie-3.3.2-cdh4.5.0/DG_QuickStart.html, and tried to run sample programs provided. However, it always fails with the following error. Looks like the workflow is not getting run at all. The Console URL field in the Job info is also empty. Could someone please help on this? The relevant snippet of the Oozie Job log follows. 2014-06-10 17:27:18,414 INFO ActionStartXCommand:539 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@:start:] Start action [0000000-140610172702069-oozie-usrX-W@:start:] with user-retry state : userRetryCount [0], userRetryMax [0], userRetryInterval [10] 2014-06-10 17:27:18,417 WARN ActionStartXCommand:542 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@:start:] [***0000000-140610172702069-oozie-usrX-W@:start:***]Action status=DONE 2014-06-10 17:27:18,417 WARN ActionStartXCommand:542 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@:start:] [***0000000-140610172702069-oozie-usrX-W@:start:***]Action updated in DB! 2014-06-10 17:27:18,576 INFO ActionStartXCommand:539 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@mr-node] Start action [0000000-140610172702069-oozie-usrX-W@mr-node] with user-retry state : userRetryCount [0], userRetryMax [0], userRetryInterval [10] 2014-06-10 17:27:19,188 WARN MapReduceActionExecutor:542 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@mr-node] credentials is null for the action 2014-06-10 17:27:19,423 WARN ActionStartXCommand:542 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@mr-node] Error starting action [mr-node]. ErrorType [TRANSIENT], ErrorCode [JA009], Message [JA009: Unknown rpc kind RPC_WRITABLE] org.apache.oozie.action.ActionExecutorException: JA009: Unknown rpc kind RPC_WRITABLE at org.apache.oozie.action.ActionExecutor.convertExceptionHelper(ActionExecutor.java:418) at org.apache.oozie.action.ActionExecutor.convertException(ActionExecutor.java:392) at org.apache.oozie.action.hadoop.JavaActionExecutor.submitLauncher(JavaActionExecutor.java:773) at org.apache.oozie.action.hadoop.JavaActionExecutor.start(JavaActionExecutor.java:927) at org.apache.oozie.command.wf.ActionStartXCommand.execute(ActionStartXCommand.java:211) at org.apache.oozie.command.wf.ActionStartXCommand.execute(ActionStartXCommand.java:59) at org.apache.oozie.command.XCommand.call(XCommand.java:277) at org.apache.oozie.service.CallableQueueService$CompositeCallable.call(CallableQueueService.java:326) at org.apache.oozie.service.CallableQueueService$CompositeCallable.call(CallableQueueService.java:255) at org.apache.oozie.service.CallableQueueService$CallableWrapper.run(CallableQueueService.java:175) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:744) Caused by: org.apache.hadoop.ipc.RemoteException(java.io.IOException): Unknown rpc kind RPC_WRITABLE at org.apache.hadoop.ipc.Client.call(Client.java:1238) at org.apache.hadoop.ipc.WritableRpcEngine$Invoker.invoke(WritableRpcEngine.java:225) at org.apache.hadoop.mapred.$Proxy30.getDelegationToken(Unknown Source) at org.apache.hadoop.mapred.JobClient.getDelegationToken(JobClient.java:2125) at org.apache.oozie.service.HadoopAccessorService.createJobClient(HadoopAccessorService.java:372) at org.apache.oozie.action.hadoop.JavaActionExecutor.createJobClient(JavaActionExecutor.java:970) at org.apache.oozie.action.hadoop.JavaActionExecutor.submitLauncher(JavaActionExecutor.java:723) ... 10 more 2014-06-10 17:27:19,426 INFO ActionStartXCommand:539 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@mr-node] Next Retry, Attempt Number [1] in [60,000] milliseconds 2014-06-10 17:28:19,468 INFO ActionStartXCommand:539 - USER[userXXX] GROUP[-] TOKEN[] APP[map-reduce-wf] JOB[0000000-140610172702069-oozie-usrX-W] ACTION[0000000-140610172702069-oozie-usrX-W@mr-node] Start action [0000000-140610172702069-oozie-usrX-W@mr-node] with user-retry state : userRetryCount [0], userRetryMax [0], userRetryInterval [10]

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  • java.rmi.UnmarshalException: unable to pull client classes by server

    - by andrews
    Hi, I have an RMI client/server set-up on two machines that works fine in a simple situation when the server doesn't require a client-side defned class. However, when I need to use a class defined on the client side I am unable to have the server unmarshall those classes. I suspect this is an issue with my java.rmi.server.codebase property that I pass in as argument to the client app. I followed Sun's RMI Tutorial trail and I think I have followed the steps exactly except that I don't specify a classpath argument when executing client and server because they execute in the directory right above the root package directory (however I tried that too with no effect). The exceptions I get when attempting to execute the different client-side combinations described in detail below are all the same: RmiServer exception: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: java.lang.ClassNotFoundException: test.MyTask at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:353) at sun.rmi.transport.Transport$1.run(Transport.java:177) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:173) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:636) at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:142) at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:178) at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:132) at $Proxy0.execute(Unknown Source) at test.myClient.main(myClient.java:32) The details are: My client/server rmi is set up over a home network behind a router. The router is assigned to a static ip address I will call myhostname. Appropriate port-mapping is set-up in the router that points to the right machines. role, machine, os, ip-address: server, venice, linux ubuntu 9.10, 10.0.1.2 client, naples, mac os x leopard, 10.0.1.4 I startup the server side as follows inside /home/andrews/workspace/epsilon/bin: 1 starting registry on the default port 1099: venice% rmiregistry & 2 starting web-server on port 2001 pointing to code base for common interfaces: venice% java webserver/ClassFileServer 2001 /home/andrew/workspace/epsilon/bin 3 starting server app (main class in test/myServer) which registers the server object: venice% java -Djava.rmi.server.codebase="http://myhostname:2001/" -Djava.security.policy=server.policy -Djava.rmi.server.hostname=myhostname test/myServer & Now the client side inside /Users/andrews/Development/Java/workspace/epsilon/bin: 1 start a local web server that can server client-side classes to the server (not sure if this is needed, but I added I tried it, and still no success; I have added port-mapping to the router for 2001 to venice, for 2002 to naples) naples$ java webserver/ClassFileServer 2002 /Users/andrews/Development/Java/workspace/epsilon/bin/ Trying to run the client (note: I don't specify the -cp argument because client executes right above the root package directory): 1 try #1 using an http hostname naples$ java -Djava.rmi.server.codebase=http://10.0.1.4:2002/ -Djava.security.policy=client.policy test.myClient myhostname Note 1: the myhostname argument at the end is passed-in to the client so that it resolves to server's rmi hostname. Note 2: I tried using localhost:2002 instead of 10.0.1.4:2002 too. Note 3: I tried using myhostname:2002 since myhostname is assigned to the router and I have proper port-mapping set-up, this address should resolve to naples and not venice 2 try #2: naples$ java -Djava.rmi.server.codebase=file:/Users/andrews/Development/Java/workspace/epsilon/bin/ -Djava.security.policy=client.policy test.myClient myhostname Note 1: the code base url format is correct, I created a small program to convert current file directory path into a url and used that. using file:///Users... has same effect. Other notes: 1 my server and client policy files correctly specify the path, as I've tested this setup with good and bad paths, and getting a security exception for bad path 2 this setup works if I don't use client-side defined objects, the client connects correctly to the server and the server executes. 3 when I place the client-side class on the server in the server's classpath, all executes fine. All help is appreciated.

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  • Synchronizing issue: I want the main thread to be run before another thread but it sometimes doesn´t

    - by Rox
    I have done my own small concurrency framework (just for learning purposes) inspired by the java.util.concurrency package. This is about the Callable/Future mechanism. My code below is the whole one and is compilable and very easy to understand. My problem is that sometimes I run into a deadlock where the first thread (the main thread) awaits for a signal from the other thread. But then the other thread has already notified the main thread before the main thread went into waiting state, so the main thread cannot wake up. FutureTask.get() should always be run before FutureTask.run() but sometimes the run() method (which is called by new thread) runs before the get() method (which is called by main thread). I don´t know how I can prevent that. This is a pseudo code of how I want the two threads to be run. //From main thread: Executor.submit().get() (in get() the main thread waits for new thread to notify) ->submit() calls Executor.execute(FutureTask object) -> execute() starts new thread -> new thread shall notify `main thread` I cannot understand how the new thread can start up and run faster than the main thread that actually starts the new thread. Main.java: public class Main { public static void main(String[] args) { new ExecutorServiceExample(); } public Main() { ThreadExecutor executor = new ThreadExecutor(); Integer i = executor.submit(new Callable<Integer>() { @Override public Integer call() { return 10; } }).get(); System.err.println("Value: "+i); } } ThreadExecutor.java: public class ThreadExecutor { public ThreadExecutor() {} protected <V> RunnableFuture<V> newTaskFor(Callable c) { return new FutureTask<V>(c); } public <V> Future<V> submit(Callable<V> task) { if (task == null) throw new NullPointerException(); RunnableFuture<V> ftask = newTaskFor(task); execute(ftask); return ftask; } public void execute(Runnable r) { new Thread(r).start(); } } FutureTask.java: import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.ReentrantLock; import java.util.logging.Level; import java.util.logging.Logger; public class FutureTask<V> implements RunnableFuture<V> { private Callable<V> callable; private volatile V result; private ReentrantLock lock = new ReentrantLock(); private Condition condition = lock.newCondition(); public FutureTask(Callable callable) { if (callable == null) throw new NullPointerException(); this.callable = callable; } @Override public void run() { acquireLock(); System.err.println("RUN"+Thread.currentThread().getName()); V v = this.callable.call(); set(v); condition.signal(); releaseLock(); } @Override public V get() { acquireLock(); System.err.println("GET "+Thread.currentThread().getName()); try { condition.await(); } catch (InterruptedException ex) { Logger.getLogger(FutureTask.class.getName()).log(Level.SEVERE, null, ex); } releaseLock(); return this.result; } public void set(V v) { this.result = v; } private void acquireLock() { lock.lock(); } private void releaseLock() { lock.unlock(); } } And the interfaces: public interface RunnableFuture<V> extends Runnable, Future<V> { @Override void run(); } public interface Future<V> { V get(); } public interface Callable<V> { V call(); }

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  • is it right to call ejb bean from thread by ThreadPoolExecutor?

    - by kislo_metal
    I trying to call some ejb bean method from tread. and getting error : (as is glassfish v3) Log Level SEVERE Logger javax.enterprise.system.std.com.sun.enterprise.v3.services.impl Name-Value Pairs {_ThreadName=Thread-1, _ThreadID=42} Record Number 928 Message ID java.lang.NullPointerException at ua.co.rufous.server.broker.TempLicService.run(TempLicService.java Complete Message 35) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) here is tread public class TempLicService implements Runnable { String hash; //it`s Stateful bean @EJB private LicActivatorLocal lActivator; public TempLicService(String hash) { this.hash= hash; } @Override public void run() { lActivator.proccessActivation(hash); } } my ThreadPoolExecutor public class RequestThreadPoolExecutor extends ThreadPoolExecutor { private boolean isPaused; private ReentrantLock pauseLock = new ReentrantLock(); private Condition unpaused = pauseLock.newCondition(); private static RequestThreadPoolExecutor threadPool; private RequestThreadPoolExecutor() { super(1, Integer.MAX_VALUE, 10, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>()); System.out.println("RequestThreadPoolExecutor created"); } public static RequestThreadPoolExecutor getInstance() { if (threadPool == null) threadPool = new RequestThreadPoolExecutor(); return threadPool; } public void runService(Runnable task) { threadPool.execute(task); } protected void beforeExecute(Thread t, Runnable r) { super.beforeExecute(t, r); pauseLock.lock(); try { while (isPaused) unpaused.await(); } catch (InterruptedException ie) { t.interrupt(); } finally { pauseLock.unlock(); } } public void pause() { pauseLock.lock(); try { isPaused = true; } finally { pauseLock.unlock(); } } public void resume() { pauseLock.lock(); try { isPaused = false; unpaused.signalAll(); } finally { pauseLock.unlock(); } } public void shutDown() { threadPool.shutdown(); } //<<<<<< creating thread here public void runByHash(String hash) { Runnable service = new TempLicService(hash); threadPool.runService(service); } } and method where i call it (it is gwt servlet, but there is no proble to call thread that not contain ejb) : @Override public Boolean submitHash(String hash) { System.out.println("submiting hash"); try { if (tBoxService.getTempLicStatus(hash) == 1) { //<<< here is the call RequestThreadPoolExecutor.getInstance().runByHash(hash); return true; } } catch (NoResultException e) { e.printStackTrace(); } return false; } I need to organize some pool of submitting hash to server (calls of LicActivator bean), is ThreadPoolExecutor design good idea and why it is not working in my case? (as I know we can`t create thread inside bean, but could we call bean from different threads? ). If No, what is the bast practice for organize such request pool? Thanks. << Answer: I am using DI (EJB 3.1) soo i do not need any look up here. (application packed in ear and both modules in it (web module and ejb), it works perfect for me). But I can use it only in managed classes. So.. 2.Can I use manual look up in Tread ? Could I use Bean that extends ThreadPoolExecutor and calling another bean that implements Runnable ? Or it is not allowed ?

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  • Webdriver PageObject Implementation using PageFactory in Java

    - by kamal
    here is what i have so far: A working Webdriver based Java class, which logs-in to the application and goes to a Home page: import java.io.File; import java.io.IOException; import java.util.concurrent.TimeUnit; import org.apache.commons.io.FileUtils; import org.openqa.selenium.By; import org.openqa.selenium.OutputType; import org.openqa.selenium.TakesScreenshot; import org.openqa.selenium.WebDriver; import org.openqa.selenium.firefox.FirefoxDriver; import org.openqa.selenium.firefox.FirefoxProfile; import org.testng.AssertJUnit; import org.testng.annotations.AfterMethod; import org.testng.annotations.BeforeMethod; import org.testng.annotations.Test; public class MLoginFFTest { private WebDriver driver; private String baseUrl; private String fileName = "screenshot.png"; @BeforeMethod public void setUp() throws Exception { FirefoxProfile profile = new FirefoxProfile(); profile.setPreference("network.http.phishy-userpass-length", 255); profile.setAssumeUntrustedCertificateIssuer(false); driver = new FirefoxDriver(profile); baseUrl = "https://a.b.c.d/"; driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS); } @Test public void testAccountLogin() throws Exception { driver.get(baseUrl + "web/certLogon.jsp"); driver.findElement(By.name("logonName")).clear(); AssertJUnit.assertEquals(driver.findElement(By.name("logonName")) .getTagName(), "input"); AssertJUnit.assertEquals(driver.getTitle(), "DA Logon"); driver.findElement(By.name("logonName")).sendKeys("username"); driver.findElement(By.name("password")).clear(); driver.findElement(By.name("password")).sendKeys("password"); driver.findElement(By.name("submit")).click(); driver.findElement(By.linkText("Account")).click(); AssertJUnit.assertEquals(driver.getTitle(), "View Account"); } @AfterMethod public void tearDown() throws Exception { File screenshot = ((TakesScreenshot) driver) .getScreenshotAs(OutputType.FILE); try { FileUtils.copyFile(screenshot, new File(fileName)); } catch (IOException e) { e.printStackTrace(); } driver.quit(); } } Now as we see there are 2 pages: 1. Login page, where i have to enter username and password, and homepage, where i would be taken, once the authentication succeeds. Now i want to implement this as PageObjects using Pagefactory: so i have : package com.example.pageobjects; import static com.example.setup.SeleniumDriver.getDriver; import java.util.concurrent.TimeUnit; import org.openqa.selenium.support.PageFactory; import org.openqa.selenium.support.ui.ExpectedCondition; import org.openqa.selenium.support.ui.FluentWait; import org.openqa.selenium.support.ui.Wait; public abstract class MPage<T> { private static final String BASE_URL = "https://a.b.c.d/"; private static final int LOAD_TIMEOUT = 30; private static final int REFRESH_RATE = 2; public T openPage(Class<T> clazz) { T page = PageFactory.initElements(getDriver(), clazz); getDriver().get(BASE_URL + getPageUrl()); ExpectedCondition pageLoadCondition = ((MPage) page).getPageLoadCondition(); waitForPageToLoad(pageLoadCondition); return page; } private void waitForPageToLoad(ExpectedCondition pageLoadCondition) { Wait wait = new FluentWait(getDriver()) .withTimeout(LOAD_TIMEOUT, TimeUnit.SECONDS) .pollingEvery(REFRESH_RATE, TimeUnit.SECONDS); wait.until(pageLoadCondition); } /** * Provides condition when page can be considered as fully loaded. * * @return */ protected abstract ExpectedCondition getPageLoadCondition(); /** * Provides page relative URL/ * * @return */ public abstract String getPageUrl(); } And for login Page not sure how i would implement that, as well as the Test, which would call these pages.

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  • bidirectional OneToOne Mapping : From Entity to subclass and from superclass to Entity?

    - by Teocali
    I'm trying to establish a tricky bidirectional OneToOne mapping in hibernate. I got the following classes : @Entity @Inheritance(strategy = InheritanceType.JOINED) public class Parent { @OneToOne private AnotherEntity anotherEntity; } @Entity public class Child1 extends Parent{} @Entity public class Child2 extends Parent{} @Entity public class AnotherEntity { @OneToOne(mappedBy = "anotherEntity") private Child1 child1; @OneToOne(mappedBy = "anotherEntity") private Child1 child2; } The problem here is when I'm launching the application : I got the following message : org.hibernate.MappingException: property [anotherEntity] not found on entity [Child1] at org.hibernate.mapping.PersistentClass.getRecursiveProperty(PersistentClass.java:429) at org.hibernate.mapping.PersistentClass.getReferencedProperty(PersistentClass.java:369) at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1614) at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1362) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1727) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1778) at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.buildSessionFactory(LocalSessionFactoryBuilder.java:189) at org.springframework.orm.hibernate4.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:350) at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:335) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:567) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464) at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645) at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508) at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449) at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133) at javax.servlet.GenericServlet.init(GenericServlet.java:160) at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1266) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1185) at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080) at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5015) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5302) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:962) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:536) at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1471) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:836) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:761) at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1436) at org.apache.catalina.manager.ManagerServlet.deploy(ManagerServlet.java:673) at org.apache.catalina.manager.ManagerServlet.doPut(ManagerServlet.java:431) at javax.servlet.http.HttpServlet.service(HttpServlet.java:644) at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:581) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662) One obvious solution would be to move the anotherEntity field to Child1 and Child2, but it would mean lose the link from Parent to AnotherEntity. Any help welcome.

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  • ASP.NET MVC 3 - New Features

    - by imran_ku07
    Introduction:          ASP.NET MVC 3 just released by ASP.NET MVC team which includes some new features, some changes, some improvements and bug fixes. In this article, I will show you the new features of ASP.NET MVC 3. This will help you to get started using the new features of ASP.NET MVC 3. Full details of this announcement is available at Announcing release of ASP.NET MVC 3, IIS Express, SQL CE 4, Web Farm Framework, Orchard, WebMatrix.   Description:       New Razor View Engine:              Razor view engine is one of the most coolest new feature in ASP.NET MVC 3. Razor is speeding things up just a little bit more. It is much smaller and lighter in size. Also it is very easy to learn. You can say ' write less, do more '. You can get start and learn more about Razor at Introducing “Razor” – a new view engine for ASP.NET.         Granular Request Validation:             Another biggest new feature in ASP.NET MVC 3 is Granular Request Validation. Default request validator will throw an exception when he see < followed by an exclamation(like <!) or < followed by the letters a through z(like <s) or & followed by a pound sign(like &#123) as a part of querystring, posted form, headers and cookie collection. In previous versions of ASP.NET MVC, you can control request validation using ValidateInputAttriubte. In ASP.NET MVC 3 you can control request validation at Model level by annotating your model properties with a new attribute called AllowHtmlAttribute. For details see Granular Request Validation in ASP.NET MVC 3.       Sessionless Controller Support:             Sessionless Controller is another great new feature in ASP.NET MVC 3. With Sessionless Controller you can easily control your session behavior for controllers. For example, you can make your HomeController's Session as Disabled or ReadOnly, allowing concurrent request execution for single user. For details see Concurrent Requests In ASP.NET MVC and HowTo: Sessionless Controller in MVC3 – what & and why?.       Unobtrusive Ajax and  Unobtrusive Client Side Validation is Supported:             Another cool new feature in ASP.NET MVC 3 is support for Unobtrusive Ajax and Unobtrusive Client Side Validation.  This feature allows separation of responsibilities within your web application by separating your html with your script. For details see Unobtrusive Ajax in ASP.NET MVC 3 and Unobtrusive Client Validation in ASP.NET MVC 3.       Dependency Resolver:             Dependency Resolver is another great feature of ASP.NET MVC 3. It allows you to register a dependency resolver that will be used by the framework. With this approach your application will not become tightly coupled and the dependency will be injected at run time. For details see ASP.NET MVC 3 Service Location.       New Helper Methods:             ASP.NET MVC 3 includes some helper methods of ASP.NET Web Pages technology that are used for common functionality. These helper methods includes: Chart, Crypto, WebGrid, WebImage and WebMail. For details of these helper methods, please see ASP.NET MVC 3 Release Notes. For using other helper methods of ASP.NET Web Pages see Using ASP.NET Web Pages Helpers in ASP.NET MVC.       Child Action Output Caching:             ASP.NET MVC 3 also includes another feature called Child Action Output Caching. This allows you to cache only a portion of the response when you are using Html.RenderAction or Html.Action. This cache can be varied by action name, action method signature and action method parameter values. For details see this.       RemoteAttribute:             ASP.NET MVC 3 allows you to validate a form field by making a remote server call through Ajax. This makes it very easy to perform remote validation at client side and quickly give the feedback to the user. For details see How to: Implement Remote Validation in ASP.NET MVC.       CompareAttribute:             ASP.NET MVC 3 includes a new validation attribute called CompareAttribute. CompareAttribute allows you to compare the values of two different properties of a model. For details see CompareAttribute in ASP.NET MVC 3.       Miscellaneous New Features:                    ASP.NET MVC 2 includes FormValueProvider, QueryStringValueProvider, RouteDataValueProvider and HttpFileCollectionValueProvider. ASP.NET MVC 3 adds two additional value providers, ChildActionValueProvider and JsonValueProvider(JsonValueProvider is not physically exist).  ChildActionValueProvider is used when you issue a child request using Html.Action and/or Html.RenderAction methods, so that your explicit parameter values in Html.Action and/or Html.RenderAction will always take precedence over other value providers. JsonValueProvider is used to model bind JSON data. For details see Sending JSON to an ASP.NET MVC Action Method Argument.           In ASP.NET MVC 3, a new property named FileExtensions added to the VirtualPathProviderViewEngine class. This property is used when looking up a view by path (and not by name), so that only views with a file extension contained in the list specified by this new property is considered. For details see VirtualPathProviderViewEngine.FileExtensions Property .           ASP.NET MVC 3 installation package also includes the NuGet Package Manager which will be automatically installed when you install ASP.NET MVC 3. NuGet makes it easy to install and update open source libraries and tools in Visual Studio. See this for details.           In ASP.NET MVC 2, client side validation will not trigger for overridden model properties. For example, if have you a Model that contains some overridden properties then client side validation will not trigger for overridden properties in ASP.NET MVC 2 but client side validation will work for overridden properties in ASP.NET MVC 3.           Client side validation is not supported for StringLengthAttribute.MinimumLength property in ASP.NET MVC 2. In ASP.NET MVC 3 client side validation will work for StringLengthAttribute.MinimumLength property.           ASP.NET MVC 3 includes new action results like HttpUnauthorizedResult, HttpNotFoundResult and HttpStatusCodeResult.           ASP.NET MVC 3 includes some new overloads of LabelFor and LabelForModel methods. For details see LabelExtensions.LabelForModel and LabelExtensions.LabelFor.           In ASP.NET MVC 3, IControllerFactory includes a new method GetControllerSessionBehavior. This method is used to get controller's session behavior. For details see IControllerFactory.GetControllerSessionBehavior Method.           In ASP.NET MVC 3, Controller class includes a new property ViewBag which is of type dynamic. This property allows you to access ViewData Dictionary using C # 4.0 dynamic features. For details see ControllerBase.ViewBag Property.           ModelMetadata includes a property AdditionalValues which is of type Dictionary. In ASP.NET MVC 3 you can populate this property using AdditionalMetadataAttribute. For details see AdditionalMetadataAttribute Class.           In ASP.NET MVC 3 you can also use MvcScaffolding to scaffold your Views and Controller. For details see Scaffold your ASP.NET MVC 3 project with the MvcScaffolding package.           If you want to convert your application from ASP.NET MVC 2 to ASP.NET MVC 3 then there is an excellent tool that automatically converts ASP.NET MVC 2 application to ASP.NET MVC 3 application. For details see MVC 3 Project Upgrade Tool.           In ASP.NET MVC 2 DisplayAttribute is not supported but in ASP.NET MVC 3 DisplayAttribute will work properly.           ASP.NET MVC 3 also support model level validation via the new IValidatableObject interface.           ASP.NET MVC 3 includes a new helper method Html.Raw. This helper method allows you to display unencoded HTML.     Summary:          In this article I showed you the new features of ASP.NET MVC 3. This will help you a lot when you start using ASP MVC 3. I also provide you the links where you can find further details. Hopefully you will enjoy this article too.  

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  • Parallelism in .NET – Part 5, Partitioning of Work

    - by Reed
    When parallelizing any routine, we start by decomposing the problem.  Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element.  This process is called partitioning. Partitioning our tasks is a challenging feat.  There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle.  Trying to work the perfect balance between the two extremes is the goal for which we should aim.  Luckily, the Task Parallel Library automatically handles much of this process.  However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic.  It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place.  The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted.  I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them.  However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation.  Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions.  For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading.  This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks.  A task is a simple set of instructions that can be run on a PE.  Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle.  A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task.  When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc.  There’s a flaw in this approach, however.  It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task.  When we take a simple foreach loop body and implement it using the TPL, we add overhead.  First, we change the body from a simple statement to a delegate, which must be invoked.  In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it.  If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task.  By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool.  There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically.  At first, partitioning here seems simple.  A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor.  Many hand-written partitioning schemes work in this exactly manner.  This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element.  However, this is rarely the case.  Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations.  In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish.  Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations.  In this situation, the first chunks will be working far longer than the last chunks.  In order to balance the workload, many implementations create many small chunks, and reuse threads.  This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately.  Chunks are determined at runtime, and start small.  They grow slowly over time, getting larger and larger.  This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads.  Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime.  In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it.  Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out.  By default, it uses a partitioning method similar to the one described above.  We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming.  When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core.  You can see that, when we started (at the top), we begin with very small bands of color.  As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning.  However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case.  With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance.  The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning.  By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available.  If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances.  These are then used by the Parallel class to split work up amongst processors.  When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition.  If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project.  This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size.  Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice.  The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

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  • KB Articles on My Oracle Support

    - by Anthony Shorten
    My Oracle Support is a valuable resource for product information and how to's. It is not just about bug fixes and service packs. To find articles pertaining to any Oracle Utilities product you logon to My Oracle Support (your DBA shoud have access at least) and use the following path to Navigate to the articles: Knowledge - More Applications - Industry Solutions - Utilities You are then presented with a list of products, just select the one that you are interested in. You are then pressented with a list of articles available (25 per page). You can also search on keywords for articles. Here is a list of ones I find useful (with KB ID in []): Customer Care and Billing V2.2.0 Unix Installation Questions [ID 844645.1] Known Framework (FW) Errors [ID 783823.1] Weblogic 10 MP2 CCB Support Question [ID 1119383.1] CCB v2.2.0 Performance Problem Under Heavy Concurrent User Load [ID 808233.1] - This is a description of a patch for performance What Is The Meaning Of The TRUE And FALSE Setting For REL_CBL_THREAD_MEM Within OUAF For Oracle Utilities CCB, BI & ETM [ID 783444.1] Oracle Utilities Framework Support Utility [ID 1079640.1] How to customize XAI error messages? [ID 1061394.1] Oracle Utilities Application Framework - Patch Installation [ID 974985.1] Action Plan for Creating a Weblogic Custom Authentication Provider [ID 954417.1] How to set up XAI service on multiple servers to provide redundancy? [ID 854215.1] The first one is very useful and answer lots of how to questions for installation.

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  • ParallelWork: Feature rich multithreaded fluent task execution library for WPF

    - by oazabir
    ParallelWork is an open source free helper class that lets you run multiple work in parallel threads, get success, failure and progress update on the WPF UI thread, wait for work to complete, abort all work (in case of shutdown), queue work to run after certain time, chain parallel work one after another. It’s more convenient than using .NET’s BackgroundWorker because you don’t have to declare one component per work, nor do you need to declare event handlers to receive notification and carry additional data through private variables. You can safely pass objects produced from different thread to the success callback. Moreover, you can wait for work to complete before you do certain operation and you can abort all parallel work while they are in-flight. If you are building highly responsive WPF UI where you have to carry out multiple job in parallel yet want full control over those parallel jobs completion and cancellation, then the ParallelWork library is the right solution for you. I am using the ParallelWork library in my PlantUmlEditor project, which is a free open source UML editor built on WPF. You can see some realistic use of the ParallelWork library there. Moreover, the test project comes with 400 lines of Behavior Driven Development flavored tests, that confirms it really does what it says it does. The source code of the library is part of the “Utilities” project in PlantUmlEditor source code hosted at Google Code. The library comes in two flavors, one is the ParallelWork static class, which has a collection of static methods that you can call. Another is the Start class, which is a fluent wrapper over the ParallelWork class to make it more readable and aesthetically pleasing code. ParallelWork allows you to start work immediately on separate thread or you can queue a work to start after some duration. You can start an immediate work in a new thread using the following methods: void StartNow(Action doWork, Action onComplete) void StartNow(Action doWork, Action onComplete, Action<Exception> failed) For example, ParallelWork.StartNow(() => { workStartedAt = DateTime.Now; Thread.Sleep(howLongWorkTakes); }, () => { workEndedAt = DateTime.Now; }); Or you can use the fluent way Start.Work: Start.Work(() => { workStartedAt = DateTime.Now; Thread.Sleep(howLongWorkTakes); }) .OnComplete(() => { workCompletedAt = DateTime.Now; }) .Run(); Besides simple execution of work on a parallel thread, you can have the parallel thread produce some object and then pass it to the success callback by using these overloads: void StartNow<T>(Func<T> doWork, Action<T> onComplete) void StartNow<T>(Func<T> doWork, Action<T> onComplete, Action<Exception> fail) For example, ParallelWork.StartNow<Dictionary<string, string>>( () => { test = new Dictionary<string,string>(); test.Add("test", "test"); return test; }, (result) => { Assert.True(result.ContainsKey("test")); }); Or, the fluent way: Start<Dictionary<string, string>>.Work(() => { test = new Dictionary<string, string>(); test.Add("test", "test"); return test; }) .OnComplete((result) => { Assert.True(result.ContainsKey("test")); }) .Run(); You can also start a work to happen after some time using these methods: DispatcherTimer StartAfter(Action onComplete, TimeSpan duration) DispatcherTimer StartAfter(Action doWork,Action onComplete,TimeSpan duration) You can use this to perform some timed operation on the UI thread, as well as perform some operation in separate thread after some time. ParallelWork.StartAfter( () => { workStartedAt = DateTime.Now; Thread.Sleep(howLongWorkTakes); }, () => { workCompletedAt = DateTime.Now; }, waitDuration); Or, the fluent way: Start.Work(() => { workStartedAt = DateTime.Now; Thread.Sleep(howLongWorkTakes); }) .OnComplete(() => { workCompletedAt = DateTime.Now; }) .RunAfter(waitDuration);   There are several overloads of these functions to have a exception callback for handling exceptions or get progress update from background thread while work is in progress. For example, I use it in my PlantUmlEditor to perform background update of the application. // Check if there's a newer version of the app Start<bool>.Work(() => { return UpdateChecker.HasUpdate(Settings.Default.DownloadUrl); }) .OnComplete((hasUpdate) => { if (hasUpdate) { if (MessageBox.Show(Window.GetWindow(me), "There's a newer version available. Do you want to download and install?", "New version available", MessageBoxButton.YesNo, MessageBoxImage.Information) == MessageBoxResult.Yes) { ParallelWork.StartNow(() => { var tempPath = System.IO.Path.Combine( Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), Settings.Default.SetupExeName); UpdateChecker.DownloadLatestUpdate(Settings.Default.DownloadUrl, tempPath); }, () => { }, (x) => { MessageBox.Show(Window.GetWindow(me), "Download failed. When you run next time, it will try downloading again.", "Download failed", MessageBoxButton.OK, MessageBoxImage.Warning); }); } } }) .OnException((x) => { MessageBox.Show(Window.GetWindow(me), x.Message, "Download failed", MessageBoxButton.OK, MessageBoxImage.Exclamation); }); The above code shows you how to get exception callbacks on the UI thread so that you can take necessary actions on the UI. Moreover, it shows how you can chain two parallel works to happen one after another. Sometimes you want to do some parallel work when user does some activity on the UI. For example, you might want to save file in an editor while user is typing every 10 second. In such case, you need to make sure you don’t start another parallel work every 10 seconds while a work is already queued. You need to make sure you start a new work only when there’s no other background work going on. Here’s how you can do it: private void ContentEditor_TextChanged(object sender, EventArgs e) { if (!ParallelWork.IsAnyWorkRunning()) { ParallelWork.StartAfter(SaveAndRefreshDiagram, TimeSpan.FromSeconds(10)); } } If you want to shutdown your application and want to make sure no parallel work is going on, then you can call the StopAll() method. ParallelWork.StopAll(); If you want to wait for parallel works to complete without a timeout, then you can call the WaitForAllWork(TimeSpan timeout). It will block the current thread until the all parallel work completes or the timeout period elapses. result = ParallelWork.WaitForAllWork(TimeSpan.FromSeconds(1)); The result is true, if all parallel work completed. If it’s false, then the timeout period elapsed and all parallel work did not complete. For details how this library is built and how it works, please read the following codeproject article: ParallelWork: Feature rich multithreaded fluent task execution library for WPF http://www.codeproject.com/KB/WPF/parallelwork.aspx If you like the article, please vote for me.

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  • F# performance vs Erlang performance, is there proof the Erlang's VM is faster?

    - by afuzzyllama
    I've been putting time into learning functional programming and I've come to the part where I want to start writing a project instead of just dabbling in tutorials/examples. While doing my research, I've found that Erlang seems to be a pretty powerful when it comes to writing concurrent software (which is my goal), but resources and tools for development aren't as mature as Microsoft development products. F# can run on linux (Mono) so that requirement is met, but while looking around on the internet I cannot find any comparisons of F# vs Erlang. Right now, I am leaning towards Erlang just because it seems to have the most press, but I am curious if there is really any performance difference between the two languages. Since I am use to developing in .NET, I can probably get up to speed with F# a lot faster than Erlang, but I cannot find any resource to convince me that F# is just as scalable as Erlang. I am most interested in simulation, which is going to be firing a lot of quickly processed messages to persistant nodes. If I have not done a good job with what I am trying to ask, please ask for more verification.

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  • Webfarm and IIS configuration tips/tricks

    - by steve schofield
    I was recently talking with some good friends about tips for performance and what an IIS Administrator could do on the server side.  I also see this question from time to time in the forums @ http://forums.iis.net.    Of course, you should test individual settings in a controlled environment while performing load testing before just implementing on your production farm.  IIS Compression enabled (both static and dynamic if possible, set it to 9)  If you are running IIS 6, check this article out by Scott Forsyth. Run FRT for long running pages (Failed Request Tracing) Sql Connection pooling in code Look at using PAL with performance counters ( http://blogs.iis.net/ganekar/archive/2009/08/12/pal-performance-analyzer-with-iis.aspx )  Look at load testing using visual studio load testing tools Log parser finding long running pages.  Here is a couple examples Look at CPU, Memory and disk counters.  Make sure the server has enough resources. Same machineKey account across all same nodes Localize content vs. using UNC based content on a single server (My UNC tag with great posts) Content expiration ETAG’s the same across all web-farms Disable Scalable Networking Pack Use YSlow or Developer tools in Chrome to help measure the client experience improvements. Additionally, some basic counters in for measuring applications is: I would recommend checking out the Chapter 17 in IIS 7 Resource kit. it was one of the chapters I authored. :) Concurrent Connections,  Request Per / Sec, Request Queued.  I strongly suggest testing one change at a time to see how it helps improve your performance.  Hopefully this post provides a few options to review in your environment.   Cheers, Steve SchofieldMicrosoft MVP - IIS

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  • Ground Control by David Baum

    - by JuergenKress
    As cloud computing moves out of the early-adopter phase, organizations are carefully evaluating how to get to the cloud. They are examining standard methods for developing, integrating, deploying, and scaling their cloud applications, and after weighing their choices, they are choosing to develop and deploy cloud applications based on Oracle Cloud Application Foundation, part of Oracle Fusion Middleware. Oracle WebLogic Server is the flagship software product of Oracle Cloud Application Foundation. Oracle WebLogic Server is optimized to run on Oracle Exalogic Elastic Cloud, the integrated hardware and software platform for the Oracle Cloud Application Foundation family. Many companies, including Reliance Commercial Finance, are adopting this middleware infrastructure to enable private cloud computing and its convenient, on-demand access to a shared pool of configurable computing resources. “Cloud computing has become an extremely critical design factor for us,” says Shashi Kumar Ravulapaty, senior vice president and chief technology officer at Reliance Commercial Finance. “It’s one of our main focus areas. Oracle Exalogic, especially in combination with Oracle WebLogic, is a perfect fit for rapidly provisioning capacity in a private cloud infrastructure.” Reliance Commercial Finance provides loans to tens of thousands of customers throughout India. With more than 1,500 employees accessing the company’s core business applications every day, the company was having trouble processing more than 6,000 daily transactions with its legacy infrastructure, especially at the end of each month when hundreds of concurrent users need to access the company’s loan processing and approval applications. Read the complete article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • SRs @ Oracle: How do I License Thee?

    - by [email protected]
    With the release of the new Sun Ray product last week comes the advent of a different software licensing model. Where Sun had initially taken the approach of '1 desktop device = one license', we later changed things to be '1 concurrent connection to the server software = one license', and while there were ways to tell how many connections there were at a time, it wasn't the easiest thing to do.  And, when should you measure concurrency?  At your busiest time, of course... but when might that be?  9:00 Monday morning this week might yield a different result than 9:00 Monday morning last week.In the acquisition of this desktop virtualization product suite Oracle has changed things to be, in typical Oracle fashion, simpler.  There are now two choices for customers around licensing: Named User licenses and Per Device licenses.Here's how they work, and some examples:The Rules1) A Sun Ray device, and PC running the Desktop Access Client (DAC), are both considered unique devices.OR, 2) Any user running a session on either a Sun Ray or an DAC is still just one user.So, you have a choice of path to go down.Some Examples:Here are 6 use cases I can think of right now that will help you choose the Oracle server software licensing model that is right for your business:Case 1If I have 100 Sun Rays for 100 users, and 20 of them use DAC at home that is 100 user licenses.If I have 100 Sun Rays for 100 users, and 20 of them use DAC at home that is 120 device licenses.Two cases using the same metrics - different licensing models and therefore different results.Case 2If I have 100 Sun Rays for 200 users, and 20 of them use DAC at home that is 200 user licenses.If I have 100 Sun Rays for 200 users, and 20 of them use DAC at home that is 120 device licenses.Same metrics - very different results.Case 3If I have 100 Sun Rays for 50 users, and 20 of them use DAC at home that is 50 user licenses.If I have 100 Sun Rays for 50 users, and 20 of them use DAC at home that is 120 device licenses.Same metrics - but again - very different results.Based on the way your business operates you should be able to see which of the two licensing models is most advantageous to you.Got questions?  I'll try to help.(Thanks to Brad Lackey for the clarifications!)

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