PQ59674: SESSION MANAGER DOES NOT USE PREPAREDSTATEMENT OBJECTS FOR THE SELECT STATEMENTS IN THE INVALIDATION THREAD


APAR

APAR status
Closed as program error.

Error description
The Invalidation Thread of the Session Manager does not use the
PreparedStatement object for the SELECT statements (the SELECT
statements use the normal Statement objects):
  select id , lastaccess  from  sessions
  where (  listenercnt = 0 and
  maxinactivetime >= 0 and ( 1017099692809
  - (maxinactivetime * 1000)) >
  lastaccess)
.
  select id, lastaccess from  sessions
  where ( appname = 'SDCSWebApp'  and
  listenercnt > 0 and maxinactivetime >= 0
  and ( 1017099692793 - (maxinactivetime *
  1000)) > lastaccess)
.
When using the Statement objects repeatly (every 2-3 minutes),
this causes the Oracle memory to be fragmented (the memory is
free not unallocated)
statements use the normal Statement objects):select id , lastaccess from sessionswhere ( listenercnt = 0 and, maxinactivetime>= 0 and ( 1017099692809, - (maxinactivetime * 1000))>lastaccess).select id, lastaccess from sessionswhere ( appname = 'SDCSWebApp' and, listenercnt>, 0 and maxinactivetime>= 0and ( 1017099692793 - (maxinactivetime *, 1000))>, lastaccess).When using the Statement objects repeatly (every 2-3 minutes),this causes the Oracle memory to be fragmented (the memory isfree not unallocated)
Local fix
Problem summary
****************************************************************
* USERS AFFECTED: WebSphere Application Server - Session       *
*                 Manager Users                                *
****************************************************************
* PROBLEM DESCRIPTION: Ordinary JDBC select statements being   *
*                      executed in the invalidation path       *
*                      were causing the Oracle database        *
*                      memory to be fragmented.                *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The invalidation thread in the session manager runs normally
every 3-4 minutes by default.  As part of the invalidation
process, select statements are executed to obtain the eligible
session candidate list for invalidation.  We were using simple
jdbc statements to execute the select statement which was
reported to have caused memory fragmentation in Oracle.
Problem conclusion
In this fix the simple statements were changed to prepared
statements which will get reused for the execution of these
select statements which should help in reducing Oracle
memory fragmentation.
Temporary fix
PQ59674.jar
Comments
APAR information
APAR numberPQ59674
Reported component nameWAS STANDARD NT
Reported component ID5648C8301
Reported release350
StatusCLOSED PER
PENoPE
HIPERNoHIPER
Submitted date2002-04-02
Closed date2002-04-29
Last modified date2002-07-25

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:APAR is sysrouted FROM one or more of the following:

PQ63551

Modules/Macros
SESSIONS
APAR is sysrouted TO one or more of the following:PQ63551Modules/Macros

Fix information
Fixed component nameWAS STANDARD NT
Fixed component ID5648C8301

Applicable component levels
R350 PSYUP











Document Information

Product categories: Software, Application Servers, Distributed Application & Web Servers, WebSphere Application Server, General
Software version: 350
Reference #: PQ59674
IBM Group: Software Group
Modified date: 2002-07-25