Threads issue

[Sébastien Bahloul <se...@gmail.com>]

To Apache LDAP API guys,

First, thank you because we are successfully using Apache LDAP API in Ldap
Synchronization Connector Open Source project (build 1.0.0-M25). But we
encountered an error that seems to be linked to its usage. That's probably
because we are using it in a wrong way, but we cannot figured why. Let me
introduce the use case: LSC is providing synchronization services based on
a source to a destination. Source can be a LDAP directory and there is a
mode to run it as a daemon. It's using LDAP Content Synchronization
Protocol to attach it to an OpenLDAP directory and to be able to catch
updated entries to sync them to a destination (database, another directory,
...). In this configuration, after 1,5 hour the JVM is throwing an
OutOfMemory error with "unable to create new native threads". You will find
below a pastebin to the thread dump that have been generated each 15
minutes which mainly shows thread pool tasks. The fact is LSC is using its
own thread pool, but my understanding of the thread dump is that most
threads are linked to MINA and to other threads WAITING for MINA threads.

http://pastebin.fr/37581

The source code that create LDAP connection through LDAP Apache API and
launches asynchronous search can be found at the following location:

https://lsc-project.org/svn/lsc/branches/v2.1/src/main/java/org/lsc/service/SyncReplSourceService.java

There's no direct use of Apache LDAP API in the rest of the project (we are
also using JNDI). If you have any idea of the reason why we are
encountering such issue or at least a method to identify it, it would be
welcomed :)

The exception:
Exception in thread "pool-1974-thread-1" java.lang.OutOfMemoryError: unable
to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.addWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.processWorkerExit(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception in thread "Sync" java.lang.NullPointerException
at
org.lsc.service.SyncReplSourceService.getNextId(SyncReplSourceService.java:292)
at org.lsc.AsynchronousRunner.run(AbstractSynchronize.java:628)
at java.lang.Thread.run(Unknown Source)


Sebastien BAHLOUL
IAM / Security specialist
Ldap Synchronization Connector : http://lsc-project.org
Blog : http://sbahloul.wordpress.com/