Re: Deadlocks in the Filestore of Silde 2.1

Hi Arne!

The stack trace tells you that another thread has the global
read/write lock. So, correctly speaking this is a "live lock". The
reason most likely is a thread that still runs and has forgotten to
release this lock.

Having said this, even switching to a deadlock free solution will not
help, as you have no deadlocks here.

Cheers

Oliver

2007/4/17, Arne v.Irmer <[email protected]>:
> Hi,
> we are using slide in our e-learning platform
> http://ews2.uni-dortmund.de in a production environment. We get into
> deep trouble with deadlocks in Slide!
> I checked out Silde 2.2pre1. In the RELEASE-NOTES-2.2 there is the sentence:
> "- New option for a fine grained, deadlock-less locking scheme"
> My question is:
> - Should I change to 2.2pre1 for my productive environment? How can I
> switch back if we discover other problems with this pre-release?
> - Is there a patch for version 2.1. that fixes these deadlocks?
>
> Please help.
> Thanks in advance
>  Arne v.Irmer
>
> Our configuration:
> Slide 2.1 with fixed hasmap "suspendedLocks" in
> org.apache.slide.store.ExtendedStore.
> using a filestore in Tomcat 5.5
>
> Here are some stacktraces from the jconsole in the case of the deadlocks:
>
> Name: http-129.217.205.43-8080-Processor3
> State: TIMED_WAITING on
> org.apache.commons.transaction.locking.GenericLock@76e9f537
> Total blocked: 273  Total waited: 332
>
> Stack trace:
> java.lang.Object.wait(Native Method)
> org.apache.commons.transaction.locking.GenericLock.acquire(GenericLock.java:241)
> org.apache.commons.transaction.locking.GenericLock.acquire(GenericLock.java:165)
> org.apache.slide.webdav.method.AbstractWebdavMethod.assureGlobalWriteLock(AbstractWebdavMethod.java:847)
> org.apache.slide.webdav.method.AbstractWebdavMethod.run(AbstractWebdavMethod.java:362)
> org.apache.slide.webdav.WebdavServlet.service(WebdavServlet.java:155)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
> org.apache.slide.webdav.filter.LogFilter.doFilter(LogFilter.java:141)
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
> org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:524)
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
> org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:419)
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
> java.lang.Thread.run(Thread.java:595)
>
> Name: http-129.217.205.43-8080-Processor3
> State: TIMED_WAITING on
> org.apache.commons.transaction.locking.GenericLock@667aeb85
> Total blocked: 44  Total waited: 80
>
> Stack trace:
> java.lang.Object.wait(Native Method)
> org.apache.commons.transaction.locking.GenericLock.acquire(GenericLock.java:241)
> org.apache.commons.transaction.locking.GenericLock.acquire(GenericLock.java:165)
> org.apache.slide.webdav.method.AbstractWebdavMethod.assureGlobalReadLock(AbstractWebdavMethod.java:838)
> org.apache.slide.webdav.method.AbstractWebdavMethod.run(AbstractWebdavMethod.java:360)
> org.apache.slide.webdav.WebdavServlet.service(WebdavServlet.java:155)
> javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
> org.apache.slide.webdav.filter.LogFilter.doFilter(LogFilter.java:141)
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
> org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:524)
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
> org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:419)
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
> java.lang.Thread.run(Thread.java:595)
>
> --
> Dipl.-Phys. Arne v.Irmer
> Medienzentrum Universität Dortmund
> Emil-Figge-Straße 50
> 44227 Dortmund
> Tel.: ++49 231 755 7127
> Fax : ++49 231 755 4597
>