• New Feature
  • Status: Closed
  • 2 Major
  • Resolution: Fixed
  • hsingh
  • Reporter: siyer
  • March 09, 2009
  • 0
  • Watchers: 0
  • February 12, 2013
  • March 13, 2009


Terracotta recommends the default/Parallel/Other collectors and not CMS, given instability (SigSEGVs, long GCs after the JVM is up for a while (e.g. days)) noticed in labs and reported by customers. Sun seems to concur that CMS can lead to process stability issues.

Therefore, recommend that the product spit a warning if it detects the CMS Collector in use on the L2 or the L2. Thanks


Saravanan Subbiah 2009-03-10

Check to see if its possible to deduct what collector is being used from with in the VM. 1.5 might expose some mechanism already.

Erh-Yuan Tsai 2009-03-13

gc names by “List gcmbeans = ManagementFactory.getGarbageCollectorMXBeans();" log warning if ConcurrentMarkSweep collector used.

Tested with ./tcbuild –no-ivy “jvmargs=-XX:+UseConcMarkSweepGC” check_one CreateRescueCandidatesYoungGCTest test.mode=normal 2>&1 | tee test.out

See log: WARN 2009-03-13 18:05:39,892 [Thread-11] INFO com.terracottatech.dso - GarbageCollector: ParNew WARN 2009-03-13 18:05:39,892 [Thread-11] INFO com.terracottatech.dso - GarbageCollector: ConcurrentMarkSweep WARN 2009-03-13 18:05:39,892 [Thread-11] WARN com.terracottatech.dso - Terracotta does not recommend ConcurrentMarkSweep Collector.

Himadri Singh 2009-10-27