PQ63551: SESSION MANAGER DOES NOT USE PREPAREDSTATEMENT OBJECTS FOR THE SELECT STATEMENTS IN THE INVALIDATION THREAD

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)
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 number PQ63551
Reported component name WEBSPHERE AE NT
Reported component ID 5630A2201
Reported release 400
Status CLOSED PER
PE NoPE
HIPER NoHIPER
Submitted date 2002-07-25
Closed date 2002-07-25
Last modified date 2002-07-25

APAR is sysrouted FROM one or more of the following:
PQ59674

APAR is sysrouted TO one or more of the following:

Modules/Macros
SESSIONS          

Fix information
Fixed component name WEBSPHERE AE NT
Fixed component ID 5630A2201

Applicable component levels
R400 PSY    UP


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > General
Operating system(s):
Software version: 400
Software edition:
Reference #: PQ63551
IBM Group: Software Group
Modified date: Jul 25, 2002