Legacy Calendar plugin issue -- errors & sluggish performance

[Jim Bethancourt]

We're using the legacy Calendar plugin (migrated slightly to work with Confluence 5), and one of our calendar navigation and loading is a bit sluggish and throws errors fairly frequently. It has a fair amount of data in it, but the same calendar works fine in our sandbox environment without any of the same issues.

The confluence log reports the following stacktrace:

org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getEvents' in class com.atlassian.confluence.extra.calendar.display.Day threw exception java.util.ConcurrentModificationException at /templates/extra/calendar/month.vm[line 38, column 38]

at org.apache.velocity.runtime.parser.node.ASTIdentifier.execute(ASTIdentifier.java:223)

at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:262)

at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:507)

at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:71)

Has anyone else run into this issue before?

Note: This is not the Team Calendars product that Atlassian offers, but the Calendar Plugin that was offered before it was commercialized.

Thanks,

Jim

[Ryan Goodwin · Accepted solution]

Hi Jim,

Have you compared the system information from both prod and staging? If the application is the same for both staging and prod, but the behavior is different, then there must be something environmentally different.

I would look to ensure the same jdk version is installed, same version of tomcat etc. Possibly run a diff on all the files under the confluence/ deployment folders.

[Jim Bethancourt]

Hi Ryan,

Turns out the solution was to upgrade the Java code to use ConcurrentHashMaps instead of HashSets. This fixed the ConcurrentModificationExceptions. There was a little bit of touching up of the javascript that needed to happen as well, but it was pretty minor.

Thanks,

Jim