PI32705;8.5.5: JVM Heapspace and High cpu usage observed when large number of TickRange instances are in one GuaranteedTargetStream instance

Download Description

PI32705 resolves the following problem:

ERROR DESCRIPTION:
Large number of TickRange instances under one GuaranteedTargetStream instance occupies a major portion of JVM heapspace observed under heapdump. High CPU also may be observed because of this.

LOCAL FIX:
None

PROBLEM SUMMARY

USERS AFFECTED:
Users of the default messaging provider for IBM WebSphere Application Server versions 7.0, 8.0 and 8.5.

PROBLEM DESCRIPTION:
Unnecessary TickRange instances occupy more heapspace and may create High CPU.

RECOMMENDATION:
None

When using Publish Subscribe in Service Integration Bus in a multi Messaging Engine scenario, Heapdump shows large number of TickRange instances under GuaranteedTargetStream which may
lead to unnecessary consumption of memory and considerable CPU cycles. One possiblility of having large number of TickRange instances is when there are a lot of silence messages which are consecutive are not getting consolidated. So it is not necessary to have these TickRange instances which belong to consecutive silence messages.

PROBLEM CONCLUSION:
Source code has been modified by consolidating the silence ticks and sending an acknowledgement for those ticks so that all "TickRange" instances will be deleted.

The fix for this APAR is currently targeted for inclusion in fix packs 7.0.0.39, 8.0.0.11 and 8.5.5.6.
Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980