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SLOW STARTUP PERFORMANCE OF THE 7.1 SERVER ON WINDOWS

Abstract

The default value for the DB2 database parameter DB_MEM_THRESH changed in DB2 version 10.5 and can lead to slow startup performance of the 7.1 server on Windows.

Content

ERROR DESCRIPTION:
It is possible to see the server startup take significantly longer to start up than is expected. The delay is experienced when the DB2 DB_MEM_THRESH value is set to 100 and there are large bufferpools.

The delay affects either, newly installed Tivoli Storage Manager Version 7.1.x, or upgrades from Tivoli Storage Manager V5.x to 7.1.x on Windows systems.

Upgrades from V6.x to 7.1.0.00 or higher do not show this behavior, since the DB_MEM_THRESH value is not changed to 100. The delay does not affect normal server operations, only server startup.

Tivoli Storage Manager Versions Affected: 7.1

Customer/L2 Diagnostics: The following commands can be run on a
DB2 command line to verify the setting for DB_MEM_THRESH.

db2 connect to TSMDB1
db2 get db cfg for TSMDB1 | find "DB_MEM_THRESH"

Output should be similar to the following.

C:\Program Files\Tivoli\TSM\db2\BIN>db2 get db cfg for TSMDB1 |
find
"DB_MEM_THRESH"
Database memory threshold               (DB_MEM_THRESH) = 100

If you see DB_MEM_THRESH set to 100 and are running server version 7.1 on Windows then this APAR applies.

Initial Impact: Medium

Additional Keywords: startup start mem perf slow start up
performance

LOCAL FIX:
The following steps can be done while the TSM server is running and does not require that the TSM server be restarted.

The DB_MEM_THRESH value can be changed to the previous default
of 10 by issuing the following DB2 commands.

db2 connect to TSMDB1
db2 update db cfg for TSMDB1 using DB_MEM_THRESH 10

The output should look similar to the following.

C:\Program Files\Tivoli\TSM\db2\BIN>db2 update db cfg for TSMDB1
using
DB_MEM_THRESH 10
DB20000I  The UPDATE DATABASE CONFIGURATION command completed
successfully.