PQ83264: WEBSPHERE PLUG-IN DID NOT RESOLVE THE PRIMARY AND THE BACKUP SERVER NAMES CORRECTLY

 Fixes are available

5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for AIX
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for HP-UX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Linux
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for AIX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for HP-UX
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Solaris
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Windows
5.1.1.18: WebSphere Application Server V5.1.1 Cumulative Fix 18 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Linux
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Solaris
5.1.1.17: WebSphere Application Server V5.1.1 Cumulative Fix 17 for Windows
5.0.2.7: WebSphere Application Server Express 5.0.2 Cumulative Fix 7
5.1.0.5: WebSphere Application Server V5.1.0 Cumulative Fix 5
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Solaris
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Windows
PQ86603: IBM HTTP Server V2.0.x mod_alias/mod_rewrite conflict with V5.0 plug-in
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Solaris
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Windows
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for AIX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for AIX
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for Windows
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Windows
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Solaris
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for AIX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for Linux
5.0.2.12: WebSphere Application Server 5.0.2 Cumulative Fix 12
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for HP-UX
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for AIX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Windows
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for HP-UX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for AIX
5.0.2.17: WebSphere Application Server 5.0.2 Cumulative Fix 17 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for HP-UX
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Linux
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for HP-UX
5.1.1.9: WebSphere Application Server V5.1.1 Cumulative Fix 9 for Linux
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Solaris
5.0.2.8: WebSphere Application Server V5.0.2 Cumulative Fix 8
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Windows
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for AIX
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Windows
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Solaris
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Linux
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Windows
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for HP-UX
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for AIX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Windows
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Solaris
5.0.2.14: WebSphere Application Server 5.0.2 Cumulative Fix 14 for Windows
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for AIX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Linux
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for HP-UX
5.1.1.12: WebSphere Application Server V5.1.1 Cumulative Fix 12 for Solaris
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for AIX
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Windows
5.0.2.13: WebSphere Application Server 5.0.2 Cumulative Fix 13
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for HP-UX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Solaris
5.1.1.13: WebSphere Application Server V5.1.1 Cumulative Fix 13 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for AIX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Linux
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for Windows
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Windows
5.1.1: WebSphere Application Server Version 5.1 Fix Pack 1 (Version 5.1.1)
5.0.2.5: WebSphere Application Server 5.0.2 Cumulative Fix 5
5.0.2.18: WebSphere Application Server 5.0.2 Cumulative Fix 18 for Linux
5.1.1.11: WebSphere Application Server V5.1.1 Cumulative Fix 11 for HP-UX
5.1.1.14: WebSphere Application Server V5.1.1 Cumulative Fix 14 for HP-UX
5.0.2.15: WebSphere Application Server 5.0.2 Cumulative Fix 15 for HP-UX
5.0.2.16: WebSphere Application Server 5.0.2 Cumulative Fix 16 for Linux
5.1.1.10: WebSphere Application Server V5.1.1 Cumulative Fix 10 for Solaris
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for AIX
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for HP-UX
5.1.1.16: WebSphere Application Server V5.1.1 Cumulative Fix 16 for Linux
5.1.1.15: WebSphere Application Server V5.1.1 Cumulative Fix 15 for Linux
5.1.1.19: WebSphere Application Server V5.1.1 Cumulative Fix 19 for HP-UX



APAR status
Closed as program error.

Error description
For some internal reasons, the customer wanted to
accomplish so that some URIs are always being handled
only by one AppServer, some URIs will be handled by
other AppServer, and the rest by both AppServers in
the Cluster. It looked like an unsolvable task, but the
customer solved it. Customer created "virtual"
ServerClusters, Route & URIGroup definitions that
should accomplish it.  It is not typical, but
technically it should work, if those "virtual"
Clusters, URIGroup & Transport definitions are added
properly into the plugin-cfg.xml file. Customer did it,
but it was not working.  Later he re-aranged the
sequence of the "virtual" server clusters & it started
to work. So the main issue now  is, that the customer
has two sets of plugin-cfg.xml, where he added manually
two "virtual" clusters with the same corresponding
Route & URIGroup statements and one plugin-cfg.xml is
working & the other is not working. Customer provided
full plugin trace from both scenarios - working &
non working. Verified, that both plugin cfg files
contain the same directives with the same values, only
a sequence of some directives is different.  I think
that it should not matter.
.
When I reviewed full plugin trace from the working
plugin cfg file, I saw this information there:
STATS: ws_server_group: serverGroupCheckServerStatus:
       Checking status of ethan_CMWASdeve01ethan,
       ignoreWeights 0, markedDown 0, retryNow 0,
       wlbAllows 1 reachedMaxConnectionsLimit 0
TRACE: ws_server_group: lockedServerGroupUseServer:
       Server ethan_CMWASdeve01ethan picked, weight 0.
.
In the full plugin trace of the non working plugin
cfg file I see the following:
STATS: ws_server_group: serverGroupCheckServerStatus:
       Checking status of ethan_CMWASdeve01ethan,
       ignoreWeights 0, markedDown 0, retryNow 0,
       wlbAllows 0 reachedMaxConnectionsLimit 0
TRACE: ws_server_group: serverGroupCheckServerStatus:
       Server ethan_CMWASdeve01ethan is marked up and
       not selected; current weight 0
TRACE: ws_server_group: serverGroupGetNextPrimaryServer:
       getting the the next primary server
STATS: ws_server_group: serverGroupCheckServerStatus:
       Checking status of ripley_CMWASdeve01ripley,
       ignoreWeights 0, markedDown 0, retryNow 0,
       wlbAllows 0 reachedMaxConnectionsLimit 0
TRACE: ws_server_group: serverGroupCheckServerStatus:
       Server ripley_CMWASdeve01ripley is marked up
       and not selected; current weight 0
ERROR: ws_server_group: serverGroupNextRoundRobinServer:
       Failed to find a server; all could be down or
       have reached the maximimum connections limit
.
So the qustion is, why in the second case the
"wlbAllows 0" is logged by plugin in the trace, because
I belive that this caused this issue.
.
LoadBalanceWeight="5"is set for all cluster members.
The interesting thing is, that the request is in both
cases being handled by the original URIGroup/ServerGroup
that was not being added manualy in the plugin-cfg.xml,
in one case it works but in other case it does not.
.
This problem very likely occurs in also in WebSphere 5.1 plugin,
probably does not occur in WebSphere 4.0 plugin (But I do not
know for sure).
Local fix
Manually re-aranging ServerGroup directives in the plugin cfg
file but I do not know what pattern would work for sure.  So
I can say that we do not have a reasonable workaround.
Problem summary
****************************************************************
* USERS AFFECTED: Users of Websphere 5.0 plug-in that use      *
*                 the same server as primary or backup server  *
*                 of different server groups.                  *
****************************************************************
* PROBLEM DESCRIPTION: When the same server was used as        *
*                      primary server for multiple server      *
*                      groups, the load balance weight from a  *
*                      different server group could be used,   *
*                      thus causing the load balance failure.  *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
Plug-in did not resolve the primary and the backup server
names correctly.
Problem conclusion
When a server works as primary or backup server for multiple
server groups, load balance weight is maintaied for each server
group.  The load balance weight value associated with the
server group will be used when doing the load balance within
that server group.
Temporary fix Comments
APAR information
APAR number PQ83264
Reported component name WAS NETWRK DEPL
Reported component ID 5630A3601
Reported release 00S
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Special Attention NoSpecatt
Submitted date 2004-01-14
Closed date 2004-01-23
Last modified date 2004-01-23

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Modules/Macros
plugin          

Publications Referenced

Fix information

Applicable component levels
R003 PSY    UP
R00A PSY    UP
R00H PSY    UP
R00I PSY    UP
R00P PSY    UP
R00S PSY    UP
R00W PSY    UP
R103 PSY    UP
R10A PSY    UP
R10H PSY    UP
R10I PSY    UP
R10P PSY    UP
R10S PSY    UP
R10W PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 00S
Software edition:
Reference #: PQ83264
IBM Group: Software Group
Modified date: Jan 23, 2004