Chris, thank you for your reply. We actually did just that right before
receiving your reply and the exception seems to have gone away.
Also, we modified the method to use iter.remove() instead of iterating twice.
Was there a reason for iterating twice?
// erase and cleanup expired stuff
private void closeAndForgetOldResults() {
Iterator<FieldSearchResultSQLImpl> iter =
m_currentResults.values().iterator();
ArrayList<String> toRemove = new ArrayList<String>();
while (iter.hasNext()) {
FieldSearchResultSQLImpl r = iter.next();
if (r.isExpired()) {
LOG.debug("listSession " + r.getToken()
+ " expired; will forget it.");
iter.remove();
}
}
}
Vincent Vu Nguyen
Web Applications Developer
Division of Science Quality and Translation
Office of the Associate Director for Science
Centers for Disease Control and Prevention (CDC)
404-498-0384 [email protected]
Century Bldg 2400
Atlanta, GA 30329
-----Original Message-----
From: Chris Wilper [mailto:[email protected]]
Sent: Thursday, March 08, 2012 8:51 AM
To: Support and info exchange list for Fedora users.
Subject: Re: [fcrepo-user] ConcurrentModificationException
Hi Vincent,
Thanks for the report. This does appear to be thread-unsafe code, and it hasn't
changed significantly since 3.2 so I expect this to be an issue with 3.5 as
well. I've created this issue to track it:
https://jira.duraspace.org/browse/FCREPO-1075
At first glance, it seems that changing the type of m_currentResults to a
ConcurrentHashMap would prevent this from happening. That is, in
FieldSearchSQLImpl.java, change the following:
import java.util.HashMap;
// ...
private final HashMap<String, FieldSearchResultSQLImpl> m_currentResults =
new HashMap<String, FieldSearchResultSQLImpl>();
to this:
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
// ...
private final Map<String, FieldSearchResultSQLImpl> m_currentResults =
new ConcurrentHashMap<String, FieldSearchResultSQLImpl>();
I have compiled an alternate version of the Fedora 3.2-released revision of
that file, which includes the above changes, and have attached the .class file
to the JIRA issue above. Can you try re-running your test after putting the new
.class file into your
tomcat/webapps/fedora/WEB-INF/classes/fedora/server/search/ directory and
restarting Fedora?
Thanks,
Chris
On Wed, Mar 7, 2012 at 9:25 AM, Nguyen, Vincent (CDC/OD/OADS) (CTR)
<[email protected]> wrote:
> Hi, I’m seeing this error in the log when we try to run JMeter tests
> on our instance of fedora with about 500 concurrent users. Has anyone
> else encountered this?
>
>
>
> We’re running fedora version 3.2 on Windows Server 2008 box with Tomcat 6.
> We currently use Muradora as our front end.
>
>
>
> I initially thought the problem might be because “m_currentResults”
> was being modified by one thread as another thread was trying to
> access it in this method:
>
>
>
> // erase and cleanup expired stuff
>
> private void closeAndForgetOldResults() {
>
> Iterator<FieldSearchResultSQLImpl> iter =
>
> m_currentResults.values().iterator();
>
> ArrayList<String> toRemove = new ArrayList<String>();
>
> while (iter.hasNext()) {
>
> FieldSearchResultSQLImpl r = iter.next();
>
> if (r.isExpired()) {
>
> LOG.debug("listSession " + r.getToken()
>
> + " expired; will forget it.");
>
> toRemove.add(r.getToken());
>
> }
>
> }
>
> for (int i = 0; i < toRemove.size(); i++) {
>
> String token = toRemove.get(i);
>
> m_currentResults.remove(token);
>
> }
>
> }
>
>
>
>
>
>
>
> java.util.ConcurrentModificationException
>
> at java.util.HashMap$HashIterator.nextEntry(Unknown
> Source)
>
> at java.util.HashMap$ValueIterator.next(Unknown Source)
>
> at
> fedora.server.search.FieldSearchSQLImpl.closeAndForgetOldResults(Field
> SearchSQLImpl.java:387)
>
> at
> fedora.server.search.FieldSearchSQLImpl.findObjects(FieldSearchSQLImpl
> .java:337)
>
> at
> fedora.server.search.FieldSearchSQLModule.findObjects(FieldSearchSQLMo
> dule.java:184)
>
> at
> fedora.server.storage.DefaultDOManager.findObjects(DefaultDOManager.ja
> va:1882)
>
> at
> fedora.server.access.DefaultAccess.findObjects(DefaultAccess.java:694)
>
> at
> fedora.server.access.FedoraAPIABindingSOAPHTTPImpl.findObjects(FedoraA
> PIABindingSOAPHTTPImpl.java:214)
>
> at
> fedora.server.access.FedoraAPIABindingSOAPHTTPSkeleton.findObjects(Fed
> oraAPIABindingSOAPHTTPSkeleton.java:198)
>
> at sun.reflect.GeneratedMethodAccessor203.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.axis.providers.java.RPCProvider.invokeMethod(RPCProvider.ja
> va:397)
>
> at
> org.apache.axis.providers.java.RPCProvider.processMessage(RPCProvider.
> java:186)
>
> at
> org.apache.axis.providers.java.JavaProvider.invoke(JavaProvider.java:3
> 23)
>
> at
> org.apache.axis.strategies.InvocationStrategy.visit(InvocationStrategy
> .java:32)
>
> at
> org.apache.axis.SimpleChain.doVisiting(SimpleChain.java:118)
>
> at org.apache.axis.SimpleChain.invoke(SimpleChain.java:83)
>
> at
> org.apache.axis.handlers.soap.SOAPService.invoke(SOAPService.java:453)
>
> at
> org.apache.axis.server.AxisServer.invoke(AxisServer.java:281)
>
> at
> org.apache.axis.transport.http.AxisServlet.doPost(AxisServlet.java:699
> )
>
> at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
>
> at
> org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase
> .java:327)
>
> at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
>
> at sun.reflect.GeneratedMethodAccessor66.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:163)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:283)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> fedora.server.security.servletfilters.FilterSetup.doFilter(FilterSetup
> .java:256)
>
> at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:243)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:230)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> fedora.server.security.servletfilters.FilterSetup.doFilter(FilterSetup
> .java:256)
>
> at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:243)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:230)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> fedora.server.security.servletfilters.FilterSetup.doFilter(FilterSetup
> .java:256)
>
> at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:243)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:230)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> fedora.server.security.servletfilters.FilterSetup.doFilter(FilterSetup
> .java:256)
>
> at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:243)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:230)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> fedora.server.security.servletfilters.FilterSetup.doFilter(FilterSetup
> .java:256)
>
> at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown
> Source)
>
> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> Source)
>
> at java.lang.reflect.Method.invoke(Unknown Source)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:270)
>
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:269)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at javax.security.auth.Subject.doAsPrivileged(Unknown
> Source)
>
> at
> org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:30
> 2)
>
> at
> org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.j
> ava:243)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cationFilterChain.java:230)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.access$000(Application
> FilterChain.java:56)
>
> at
> org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilte
> rChain.java:189)
>
> at java.security.AccessController.doPrivileged(Native
> Method)
>
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterChain.java:185)
>
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.java:233)
>
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.java:191)
>
> at
> org.apache.catalina.authenticator.AuthenticatorBase.invoke(Authenticat
> orBase.java:563)
>
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:127)
>
> at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:102)
>
> at
> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:6
> 15)
>
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java:109)
>
> at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java
> :293)
>
> at
> org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor
> .java:877)
>
> at
> org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pro
> cess(Http11AprProtocol.java:594)
>
> at
> org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:167
> 5)
>
> at java.lang.Thread.run(Unknown Source)
>
>
>
>
>
>
>
> Vincent Vu Nguyen
>
>
>
>
> ----------------------------------------------------------------------
> -------- Virtualization & Cloud Management Using Capacity Planning
> Cloud computing makes use of virtualization - but cloud computing also
> focuses on allowing computing to be delivered as a service.
> http://www.accelacomm.com/jaw/sfnl/114/51521223/
> _______________________________________________
> Fedora-commons-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
>
------------------------------------------------------------------------------
Virtualization & Cloud Management Using Capacity Planning Cloud computing makes
use of virtualization - but cloud computing also focuses on allowing computing
to be delivered as a service.
http://www.accelacomm.com/jaw/sfnl/114/51521223/
_______________________________________________
Fedora-commons-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
------------------------------------------------------------------------------
Virtualization & Cloud Management Using Capacity Planning
Cloud computing makes use of virtualization - but cloud computing
also focuses on allowing computing to be delivered as a service.
http://www.accelacomm.com/jaw/sfnl/114/51521223/
_______________________________________________
Fedora-commons-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
