Re: Deadlocks in the Filestore of Silde 2.1

Hi Oliver,
how can I switch off locking and what happens in the case of a
concurrent file access?
Might it be a good idea to replace the locking code of 2.1 with code of 2.2?

Yours
 Arne

Oliver Zeigermann schrieb:
> I was just having a look at the 2.2 code and it looks that you can
> even switch off locking completely. Otherwise the locking code in 2.2
> looks much better than the code in 2.1
>
> Oliver
>
> 2007/4/17, Oliver Zeigermann <[email protected]>:
>> 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 UniversitÀt Dortmund
>> > Emil-Figge-Straße 50
>> > 44227 Dortmund
>> > Tel.: ++49 231 755 7127
>> > Fax : ++49 231 755 4597
>> >
>>


-- 
Dipl.-Phys. Arne v.Irmer
Medienzentrum UniversitÀt Dortmund
Emil-Figge-Straße 50
44227 Dortmund
Tel.: ++49 231 755 7127
Fax : ++49 231 755 4597