topic RepositoryQuerySession Memory Leak in Alfresco Forum

RepositoryQuerySession Memory Leak

davidefonta — Fri, 20 Oct 2017 19:44:33 GMT

Hi, I'm running a v4.2.0 on a Tomcat 7.0.64 with 1GB of max Heap space.I've no problems for years, but in last weeks it ran in out of memory almost once a day.I took some heap dump and made some tests, and I found the class resposible of memory retentionrg.alfresco.repo.webservice.repository.Repos

Re: RepositoryQuerySession Memory Leak

afaust — Mon, 23 Oct 2017 09:14:14 GMT

Instances of RepositoryQuerySession are retained within the Repository 2nd-level cache named "webServicesQuerySessionSharedCache", which can be configured via the alfresco-global.properties file. By default, the cache allows up to 1000 objects to be cached. Cached objects are not cleared during GC, so it is important to correctly configure the cache sizes when using extremely little memory (1GiB max heap is extremely little for Alfresco).

Re: RepositoryQuerySession Memory Leak

davidefonta — Sat, 28 Oct 2017 11:23:37 GMT

Thanks a lot Axel

I set

cache.webServicesQuerySessionSharedCache.maxItems=50

in my alfresco-global.properties and it actually works: the number of RepositoryQuerySession instances grows up to 50 and never exceeds it.

One more question.

I tried also to set

cache.webServicesQuerySessionSharedCache.timeToLiveSeconds=240
cache.webServicesQuerySessionSharedCache.maxIdleSeconds=120

but they seems not applied.

After 2 or 4 mintue of inactivity, my RepositoryQuerySession instances are still present in heap.

Maybe these parameters are not supported in my alfresco version (4.2.0)?

Re: RepositoryQuerySession Memory Leak

afaust — Sat, 28 Oct 2017 12:37:01 GMT

Yes, some configuration operations are not supported for all Alfresco versions / editions. There also is a difference if the cache in question is created as a local-only or a cluster-distributed cache in Alfresco Enterprise. In 4.2, timeToLive and maxIdle weren't used for local caches.