Java applications become unresponsive when running under a WebSphere Real Time for Real Time Linux V3 service refresh 4 Java Runtime Environment (JRE) on Red Hat Enterprise MRG V2.2.
In test conditions, under certain high stress workloads, an intermittent issue can be seen that causes applications to become unresponsive.
A small fraction of the release testing that IBM® conducts on every supported platform is affected by an outstanding intermittent issue in the Red Hat Enterprise Linux (RHEL) V6 glibc component available in MRG 2.2, which corresponds to this report: https://bugzilla.redhat.com/show_bug.cgi?id=552960. The issue is not specific to Java but can cause Java applications to become unresponsive when running under WebSphere Real Time for Real Time Linux V3 SR4 on MRG 2.2 with versions of RHEL V6 before Update 5. The problem also affects Java programs that do not directly use the Real Time Specification for Java.
The following table summarizes the impact of this issue by platform when using the IBM WebSphere Real Time V3 SR4 product on MRG 2.2 with versions of RHEL V6 before Update 5:
|Platform||Affected by glibc issue|
|IBM WebSphere Real Time for Real Time Linux on 32-bit x86||Yes|
|IBM WebSphere Real Time for Linux on 32-bit x86||No|
|IBM WebSphere Real Time for Linux on 64-bit x86||No|
Table 1. Platforms affected by the glibc issue
Diagnosing the problem
This problem might present itself in a number of ways. During testing of WebSphere Real Time for Real Time Linux, Java applications are seen to become unresponsive in certain high stress workloads that employ hundreds of active threads. You might be affected by this reported issue if your application behaves in a similar way.
Resolving the problem
This problem is not seen when using MRG 2.2 with RHEL V6 Update 5. Upgrade your environment to this level.