APAR status
Closed as program error.
Error description
This problem will affect all users of HTTPSession Memory to
memory replication and all users of the Websphere Dynamic
cache including DistributedMap users.The problem may show up
in the form of an IllegalStateException that causes
replication to stop due to broken recovery logic.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: All users of Websphere Application server *
* using HTTPSession memory to memory *
* replication and dynamic cache replication. *
****************************************************************
* PROBLEM DESCRIPTION: Data Replication service may cease to *
* function if JVM garbage collection *
* takes too long to complete. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
It is possible in a severely resource constrained system that
JVM garbage collection takes more time than the internal Data
replication connection staleness check interval. If this occurs,
the replicator will decide that its connection has ceased to
function and it will mark this connection as down. When the
client attempts to send or receive using this connection next,an
IllegalStateException is thrown by the underlying broker once
for every send or receive attempt. This causes the client to
then attempt to connect to an alternate replicator and this
process may be incorrectly repeated once for every Illegal
State Exception that is caught. This behaviour results in an
inconsistent state where in replication done by all the data
replication clients in the jvm fails, and the recovery logic
is unable to recover from this state.
Problem conclusion
The data replication recovery mechannism has been changed from
being time-based to utilise a retry count mechanism. And
the IllegalStateException handler has been changed to drive the
modified recovery mechanism. The staleness check interval has
also been increased to more reasonable numbers keeping in mind
the garbage collection time required by the application server
jvm.
This fix for this problem will be made available for the
5.0.2 release in "Websphere Application Server 5.0.2
Cumulative Fix 3".
Temporary fix Comments
APAR information |
APAR number |
PQ81536 |
Reported component name |
WAS BASE 5.0 |
Reported component ID |
5630A3600 |
Reported release |
00W |
Status |
CLOSED PER |
PE |
NoPE |
HIPER |
NoHIPER |
Special Attention |
NoSpecatt |
Submitted date |
2003-12-01 |
Closed date |
2003-12-03 |
Last modified date |
2003-12-03 |
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
Publications Referenced
Applicable component levels |
R00A PSY |
UP |
R00W PSY |
UP |
|