Pool of jpd threads

Here is the challange I'm facing: 
I have a JPD which process a client practice; there are approximately 100 orders coming each minute, so I need to set up several threads of jpd working simultaneously, but not on same client_id, otherwise I get non-consistent issues on practice state. 
So, I wrote a dispatcher which manages a pool of com.bea.jpd.ProcessDefinition; it reads client_id from coming order and if there isn't any thead already working on same client, it starts a new one, otherwise it puts the order waiting over the same thread which is actually processing that client, so that when it finishes it starts over the new order.
 
Now my challenge is, as I can't instantiate a JPD from a java class, HOW CAN I DO to construct my pool with 5 initial ready-to-use threads ?

I think that your approach is not correct. The WLI insfrastructure itself is Thread based so I do not think that you need to create a thread pool.
I solved the similar problem using the below approach:
1) Main JPD (Statefull)- Calls Helper JPD and then waits for a callback from Helper JPD
2) Helper JPD(statless) - Receives the request from Main JPD and then sends the result back to the Main JPD via the callback.
With this approach, when we get n (e.g 100) orders, WLI will automatically create n instances of Main JPD and then each Main JPD will create one instace of Helper JPD. Using this approach n threads will process n orders parallely without any special logic. Using the above approach, I solved the problem similar to yours in my project.

Similar Messages

Thread pool of daemon threads?

If I create a Thread, it can be made a daemon thread by invoking setDaemon(true). But what if I create a thread pool via java.util.concurrent.Executors.newFixedThreadPool(NTHREADS)? How can those threads be made daemon threads?
CBy

Thanks Joachim! I didn't know that the newFixedThreadPool method was overloaded.

Pool of worker threads

Hi guys,
Just wondering if you guys know of any class I can use as a pool of threads.
Normal operations applied, I can create it myself, but if there is something already I can use it is a plus.
Many Thanks,
MeTitus

Herko_ter_Horst wrote:
Take a look at the java.util.concurrent package.Indeed. http://java.sun.com/docs/books/tutorial/essential/concurrency/executors.html

Connection pools, dspMaxThreads, listener-threads and ReceiverThreads?

Hi,
We are using BPEL 10.1.3.3. Our integration uses the database adapter and the AQ adapter against the same remote database 10.1.2.3. We are experiencing problems with transaction that fails with:
java.sql.SQLException: Unable to get a physical connection from the database...there are no connections available.Error Code: 0.
Then we tried to change the connection pools to not use so many connection but now instances disappears.
The 2 connections pools are setup like this:
DBAdapter connection pool with max 10 connection
AqAdapter connection pool with max 2 connections
We have 3 domains:
Default:
dspMaxThreads 20
dspMinThreads 5
Test:
dspMaxThreads 100
dspMinThreads 5
Production:
dspMaxThreads 60
dspMinThreads 5
listener-threads and ReceiverThreads are set to 300 in the orion-ejb-jar.xml in C:\oracle\product\10.1.3.1\OracleAS_1\j2ee\oc4j_soa\application-deployments\orabpel\ejb_ob_engine
I had a look at Clemens blog about lost instances (http://clemensblog.blogspot.com/2007/07/soa-suite-10133-patchset-and-lost.html) but I cannot understand the part about listener-threads and receiverThreads. Can anybody explain how the size of the connection pools and the dspMaxThreads, ReceiveThreads andlistener-threads has to be?
Regards Pete
Here are the settings for the WorkerBean:
<message-driven-deployment name="WorkerBean" listener-threads="300" min-instances="100" resource-adapter="BPELjms">
<ejb-ref-mapping name="ejb/local/DispatcherLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/CubeEngineLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/DomainManagerLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/ActivityManagerLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/CubeDeliveryLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/MessageLocalBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/services/NotificationServiceBean" jndi-properties-file="jndi.properties" />
<ejb-ref-mapping name="ejb/local/TaskServiceBean" jndi-properties-file="jndi.properties" />
<config-property>
<config-property-name>ConnectionFactoryJndiName</config-property-name>
<config-property-value>BPELjms/BPELWorkerQueueFactory</config-property-value>
</config-property>
<config-property>
<config-property-name>DestinationName</config-property-name>
<config-property-value>BPELjms/BPELWorkerQueue</config-property-value>
</config-property>
<config-property>
<config-property-name>DestinationType</config-property-name>
<config-property-value>javax.jms.Queue</config-property-value>
</config-property>
<config-property>
<config-property-name>AcknowledgeMode</config-property-name>
<config-property-value>Auto-acknowledge</config-property-value>
</config-property>
<config-property>
<config-property-name>ReceiverThreads</config-property-name>
<config-property-value>300</config-property-value>
</config-property>
<config-property>
<config-property-name>ListenerThreadMaxIdleDuration</config-property-name>
<config-property-value>100000000</config-property-value>
</config-property>
<config-property>
<config-property-name>ListenerThreadMinBusyDuration</config-property-name>
<config-property-value>1</config-property-value>
</config-property>
<config-property>
<config-property-name>ListenerThreadMaxPollInterval</config-property-name>
<config-property-value>10</config-property-value>
</config-property>
</message-driven-deployment>Please :-)
Message was edited by:
Peter Lorenzen

Thanks Marc,
Yes I have and I got it working. If you set dspMaxThread to 90 and my connections pools to max session 90 it works. Don't understand why it has to be so high. It's potentially a lot of resources that has to be available on the database (Extra ram). But it looks like it's OK for now.
Regards Pete

Thread pool rejecting threads when I don't think it should, ideas?

Hi,
I have a server application in which I only want a specific number of simultaneous requests. If the server gets more then this number it is suppose to close the connection (sends an HTTP 503 error to the client). To do this I used a fix thread pool. When I start the server and submit the max number of requests I get the expected behavior. However if I resubmit the request (within a small period of time, e.g. 1-15 seconds after the first one) I get very odd behavior in that some of the requests are rejected. For example if I set the max to 100 the first set of requests will work fine (100 requests, 100 responses). I then submit again and a small number will be rejected (I've seen it range from 1 to 15 rejected)....
I made a small app which kind of duplicates this behavior (see below). Basically when I see is that the first time submitting requests works fine but the second time I get a rejected one. As best as I can tell none should be rejected....
Here is the code, I welcome your thoughts or if you see something I am doing wrong here...
<pre>
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
public class ThreadPoolTest {
 static AtomicInteger count = new AtomicInteger();
 public static class threaded implements Runnable {
 @Override
 public void run() {
 System.out.println("In thread: " + Thread.currentThread().getId());
 try {
 Thread.sleep(500);
 } catch (InterruptedException e) {
 System.out.println("Thread: " + Thread.currentThread().getId()
 + " interuptted");
 System.out.println("Exiting run: " + Thread.currentThread().getId());
 private static int maxThreads = 3;
 private ThreadPoolExecutor pool;
 public ThreadPoolTest() {
 super();
 pool = new java.util.concurrent.ThreadPoolExecutor(
 1, maxThreads - 1, 60L, TimeUnit.SECONDS,
 new ArrayBlockingQueue<Runnable>(1));
 public static void main(String[] args) throws InterruptedException {
 ThreadPoolTest object = new ThreadPoolTest();
 object.doThreads();
 Thread.sleep(3000);
 object.doThreads();
 object.pool.shutdown();
 try {
 object.pool.awaitTermination(60, TimeUnit.SECONDS);
 } catch (InterruptedException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 private void doThreads() {
 int submitted = 0, rejected = 0;
 int counter = count.getAndIncrement();
 for (int x = 0; x < maxThreads ; x++) {
 try {
 System.out.println("Run #: " + counter + " submitting " + x);
 pool.execute(new threaded());
 submitted++;
 catch (RejectedExecutionException re) {
 System.err.println("\tRun #: " + counter + ", submission " + x
 + " was rejected");
 System.err.println("\tQueue active: " + pool.getActiveCount());
 System.err.println("\tQueue size: " + pool.getPoolSize());
 rejected++;
 System.out.println("\n\n\tRun #: " + counter);
 System.out.println("\tSubmitted: " + (submitted + rejected));
 System.out.println("\tAccepted: " + submitted);
 System.out.println("\tRejected: " + rejected + "\n\n");
</pre>

First thank you for taking the time to reply, I do appreciate it.
jtahlborn - The code provided here is a contrived example trying to emulate the bigger app as best as I could. The actual program doesn't have any sleeps, the sleep in the secondary thread is to simulate the program doing some work & replying to a request. The sleep in the primary thread is to simulate a small delay between 'requests' to the pool. I can make this 1 second and up to (at least) 5 seconds with the same results. Additionally I can take out the sleep in the secondary thread and still see the a rejection.
EJP - Yes I am aware of the TCP/IP queue, however; I don't see that as relevant to my question. The idea is not to prevent the connection but to respond to the client saying we can't process the request (send an "HTTP 503" error). So basically if we have, say, 100 threads running then the 101st, connection will get a 503 error and the connection will be closed.
Also my test platform - Windows 7 64bit running Java 1.6.0_24-b07 (32bit) on an Intel core i7.
It occurred to me that I did not show the output of the test program. As the output shows below, the first set of requests are all processed properly. The second set of requests is not. The pool should have 2 threads and 1 slot in the queue, so by the time the second "request" is made at least 2 of the requests from the first call should be done processing, so I could possibly understand run 1, submit #2 failing but not submit 1.
<pre>
Run #: 0 submitting 0
Run #: 0 submitting 1
Run #: 0 submitting 2
In thread: 8
In thread: 9
Exiting run: 8
Exiting run: 9
 Run #: 0
 Submitted: 3
 Accepted: 3
 Rejected: 0
In thread: 8
Exiting run: 8
Run #: 1 submitting 0
In thread: 9
Run #: 1 submitting 1
 Run #: 1, submission 1 was rejected
 Queue active: 1
 Queue size: 2
Run #: 1 submitting 2
 Run #: 1
 Submitted: 3
 Accepted: 2
 Rejected: 1
In thread: 8
Exiting run: 9
Exiting run: 8
</pre>

Fixed size thread pool excepting more tasks then it should

Hello,
I have the following code in a simple program (code below)
 BlockingQueue<Runnable> q = new ArrayBlockingQueue<Runnable>(10, false);
 ThreadPoolExecutor newPool = new ThreadPoolExecutor(1, 10, 20, TimeUnit.SECONDS, q);
for (int x = 0; x < 30; x++) {
newPool.execute(new threaded());
My understanding is that this should create a thread pool that will accept 10 tasks, once there have been 10 tasks submitted I should get RejectedExecutionException, however; I am seeing that when I execute the code the pool accepts 20 execute calls before throwing RejectedExecutionException. I am on Windows 7 using Java 1.6.0_21
Any thoughts on what I am doing incorrectly?
Thanks
import java.util.concurrent.*;
public class ThreadPoolTest {
 public static class threaded implements Runnable {
 @Override
 public void run() {
 System.out.println("In thread: " + Thread.currentThread().getId());
 try {
 Thread.sleep(5000);
 } catch (InterruptedException e) {
 System.out.println("Thread: " + Thread.currentThread().getId()
 + " interuptted");
 System.out.println("Exiting thread: " + Thread.currentThread().getId());
 private static int MAX = 10;
 private Executor pool;
 public ThreadPoolTest() {
 super();
 BlockingQueue<Runnable> q = new ArrayBlockingQueue<Runnable>(MAX/2, false);
 ThreadPoolExecutor newPool = new ThreadPoolExecutor(1, MAX, 20, TimeUnit.SECONDS, q);
 pool = newPool;
 * @param args
 public static void main(String[] args) {
 ThreadPoolTest object = new ThreadPoolTest();
 object.doThreads();
 private void doThreads() {
 int submitted = 0, rejected = 0;
 for (int x = 0; x < MAX * 3; x++) {
 try {
 System.out.println(Integer.toString(x) + " submitting");
 pool.execute(new threaded());
 submitted++;
 catch (RejectedExecutionException re) {
 System.err.println("Submission " + x + " was rejected");
 rejected++;
 System.out.println("\n\nSubmitted: " + MAX*2);
 System.out.println("Accepted: " + submitted);
 System.out.println("Rejected: " + rejected);
}

I don't know what is wrong because I tried this
public static void main(String args[]) {
 BlockingQueue<Runnable> q = new ArrayBlockingQueue<Runnable>(10, false);
 ThreadPoolExecutor newPool = new ThreadPoolExecutor(1, 10, 20, TimeUnit.SECONDS, q);
 for (int x = 0; x < 100; x++) {
 System.err.println(x + ": " + q.size());
 newPool.submit(new Callable<Void>() {
 @Override
 public Void call() throws Exception {
 Thread.sleep(1000);
 return null;
}and it printed
0: 0
1: 0
2: 1
3: 2
4: 3
5: 4
6: 5
7: 6
8: 7
9: 8
10: 9
11: 10
12: 10
13: 10
14: 10
15: 10
16: 10
17: 10
18: 10
19: 10
20: 10
Exception in thread "main" java.util.concurrent.RejectedExecutionException
 at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:1768)
 at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:767)
 at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:658)
 at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:92)
 at Main.main(Main.java:36)
 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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:115)Ihave Java 6 update 24 on Linux, but I don't believe this should make a difference. Can you try my code?

How do I use a thread from the execute pool

Is there any way to use the execute pools directly from my application code? We
cannot find any reference in the documentation. This will probably happen in a
startup class, but not limited to.
Thanks,
Elli

"Elli Albek" <[email protected]> wrote in message news:406a2fd5$[email protected]..
Is there any way to use the execute pools directly from my application code? We
cannot find any reference in the documentation. This will probably happen in a
startup class, but not limited to.Weblogic's pools of execute threads are purely internal resources
and are not intended for public use.
Regards,
Slava Imeshev

Thread Pool with Min,Max. and other thread parameters

hello,
I found an Implementation of ThreadPool in the java.sun.com,but it didn't have the minimum,maximum no. of threads implemented in the code.
Could you help me find out an implementation of Thread Pool,that keeps track of minimum no. of threads,max. no. of threads in the pool,the increment size of threads,number of idle threads,idle time allowable for a thread,etc...
I also need to know if it is possible to have >5000 threads in a ThreadPool,beacuse I get OutofMemoryError,when I used a ThreadPool( which didn't have any of the above-mentioned parameters!)
Thanks!!!

Having greater then 5000 threads is a sign of a problem with your design. Threads are relativly costly
beasties. The idea of using a pool for your threads is that you won't need to use 5000 threads
simultaniously. Most OS's will have problems trying to create this many threads per process (unless you
tune the OS itself (which is normally not too difficult))
matfud

Thread pool with AT MOST one thread at a time

Hi,
I want to create a pool that creates at most one thread when it is needed. I want the pool to terminate the thread when it is idle for some time. Executors.newSingleThreadExecutor() creates a thread pool with one thread, but this thread doesn't die if idle...
The code below also doesn't work - no thread is ever created:
new ThreadPoolExecutor(0, 1, 30, TimeUnit.SECONDS,
 new LinkedBlockingQueue<Runnable>());Thanks in advance

Use Future.get().
package net.jcip.examples;
import java.util.concurrent.*;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
* RenderWithTimeBudget
* Fetching an advertisement with a time budget
* @author Brian Goetz and Tim Peierls
public class RenderWithTimeBudget {
 private static final Ad DEFAULT_AD = new Ad();
 private static final long TIME_BUDGET = 1000;
 private static final ExecutorService exec = Executors.newCachedThreadPool();
 Page renderPageWithAd() throws InterruptedException {
 long endNanos = System.nanoTime() + TIME_BUDGET;
 Future<Ad> f = exec.submit(new FetchAdTask());
 // Render the page while waiting for the ad
 Page page = renderPageBody();
 Ad ad;
 try {
 // Only wait for the remaining time budget
 long timeLeft = endNanos - System.nanoTime();
 ad = f.get(timeLeft, NANOSECONDS);
 } catch (ExecutionException e) {
 ad = DEFAULT_AD;
 } catch (TimeoutException e) {
 ad = DEFAULT_AD;
 f.cancel(true);
 page.setAd(ad);
 return page;
 Page renderPageBody() { return new Page(); }
 static class Ad {
 static class Page {
 public void setAd(Ad ad) { }
 static class FetchAdTask implements Callable<Ad> {
 public Ad call() {
 return new Ad();
}

Thread pool for Servlets

          Hi all,
          I am facing a big problem while doing a concurrent testing of my web application.
          I am testing with 60 concurrent users.
          I have set the database connection pool minimum capacity to 50, capacity increment
          to 10 and maximum capacity to 100.
          While there is no problem in getting database connection, the session variables
          are getting mixed up (i.e. the session variable for one user is coming up as that
          for another user!!!).
          Does it have something to do with configuring some pool for servlets threads or
          something?
          Please help.
          Thanks a lot in advance and best regards,
          Jaya


          Hi all,
          I am facing a big problem while doing a concurrent testing of my web application.
          I am testing with 60 concurrent users.
          I have set the database connection pool minimum capacity to 50, capacity increment
          to 10 and maximum capacity to 100.
          While there is no problem in getting database connection, the session variables
          are getting mixed up (i.e. the session variable for one user is coming up as that
          for another user!!!).
          Does it have something to do with configuring some pool for servlets threads or
          something?
          Please help.
          Thanks a lot in advance and best regards,
          Jaya

Thread pool tuning on J2ee NW04s...

Hi,
I have troubles in defining the number of threads in the pool of the server and dispatcher.
First of all, I know that there are several thread pools depending on the node you are:
- Server node: System and Application thread pool.
- Dispatcher: System thread pool.
I know that application pool is dedicated to client requests that come in and system is for the services, libs and core of the nodes.
I'd like to know if I set to a server node a certain number of threads for the System and Application pool, what would be the value of the System thread pool of the dispatcher?
As almost everything is going through the dispatcher before to reach the server node, what would be the number of System threads of the dispatcher if there are two or three server nodes? Should I multiply the number current threads of the dispatcher by the number of server nodes?
If there are a lot of P4 calls (each call needs System 2 threads, one for the request and one for the response) should I deduce the number of thread of the dispatcher using this formula if there is one server node in the worse case:
Dispatcher System Threads = Server App Threads + (Server System Threads x 2)
Thanks in advance,
Serge.

Hi Serge,
One way that you can size the number of threads is by using the monitoring stats in the VA. VA -> cluster -> dispatcher/server -> services -> monitoring -> Runtime (tab) -> Monitor Tree (tab)
then Root -> Kernel
Check the Application Threads Pool and System Threads Pool.
As long as you DON'T experience CPU bottlenecking, then you can increase the number of threads, if:
1) The ActiveThreadsCount is always at the MaximumThreadPoolSize
2) You are noticing the WaitingTasksCount is always high.
If you are experiencing CPU bottlenecking then increasing the number of threads is useless.
Regards
Anthony

Creating Thread Pool with Executors.newFixedThreadPool(poolSize)

I am creating a server socket and want a Thread pool to limit the number of threads created for serving each clients. I have written a code:
private ExecutorService threadPool;
//Creating a Thread Pool for handling new sessions
threadPool=ThreadPool.createSessionThreadPool(poolSize);
and in my main listen logic:
serverSocket = new ServerSocket(listenPort);
clientSocket = serverSocket.accept();
                    threadPool.execute(new Runnable(){
                         public void run(){
                              handleConnection();
and in handleConnection I am trying to read the inputstream in a while loop:
public void handleConnection(){
BufferedReader in=null;
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
while (true) {
if((fullCommandString = in.readLine()) ==null){
wait(); // I assume that this wait will block the thread and keep the thread back in to the pool.
                    System.out.println(Thread.currentThread().getName() + " received the message");
                    System.out.println("echo: " + fullCommandString);
                    out.println("230 reply back \r\n");
why don't it keep the thread back in the pool when I call the wait() ? Is it since the thread is still active in reading the input stream? If so can any one hepl me with a snippet which will keep the thread back in the pool when there is noting on the input stream to read.

Hi,
The call to wait does not return the thread pool back to the pool. The thread will be associated with your runnable as long as your run method hasn't returned.
It looks like you instead want to use NIO if you want to use a few threads to handle many clients.
Kaj

Socket in pooled thread

I am using a ExecutorService (fixed thread pool) for client threads. Every client thread creates a socket connection. I was wondering if there is a way to keep the socket connection open for every pooled thread or if I have to have an extra pool for those socket connections.

Yes, just put it somewhere where the Runnables can find it.

Does thread pool really help

Friends,
I wanted your opinion on whether thread pools really help. Some people are of the opinion that thread pools don't really make much difference. On what basis should I make a decision whether to go for a pool or not? Is the reason that I want to limit the number of threads spawned a valid reason for pooling or it depends on the fact that for how much duration each of the threads is going to remain busy?
Can anyone please comment?
Thanks,
praddyB

sztejkat wrote:
I have run into a similar question.
The answer is, as usual, "it depends".
One delegates work to worker thread if things to be done are too long to wait for completion. This is a true sentence.
I have found that it is worth to use pool of worker threads if I need to spawn multiple, but not concurently accessing resources, lengthy tasks which should not wait for each other.
That applies to threads. It provides no basis for pools.
If tasks are to access same resource there is no point in getting a separate thread for each of them. One may get into many deadlocking troubles.
Not sure what you mean by that. If you are actually deadlocking on a single resource then you are doing something weird. Deadlocks result due to multiple resources (and incorrect access).
[http://www.javaworld.com/javaworld/jw-10-2001/jw-1012-deadlock.html]
Blocking on the other hand occurs with a single resource. Obviously if a single resource is used exclusively or primarily in thread processing then either don't use threads or re-arch to split it up.
Worker thread/pool is usually an application wide resource where one does throw "things to be done in background" or "things which can't hold current thread code flow".
Threads, pooled or not, can be the primary focus of the application. I would suppose that when someone considers using a pool that in fact in almost all cases the work tasks to be done are either the primary or a substantial part of the processing.

Thread callbacks across thread pools

Correct me if I'm wrong, but apparently calls such as PostDeferredCallToThread() don't work between thread pools. If I create a thread pool in a main program (operating in the default thread pool) and make threads, I can't make calls to callbacks in the new thread pool. Thread-safe queues and variables, on the other hand, still seem to work.

See the example in my answer to your other thread.
Proud to use LW/CVI from 3.1 on.
My contributions to the Developer Zone Community
If I have helped you, why not giving me a kudos?

Pool of jpd threads

Similar Messages

Maybe you are looking for