IBM Support

kuddb2 process randomly crashes

Troubleshooting


Problem

An instance of ITM DB2 agent V6.2.2, used to monitor a DB2 V9.1 Workgroup Server Edition, crashes from time to time.The problem does not occur when using the same ITM agent level to monitor a DB2 V9.1 Enterprise Edition.

Symptom

The errpt shows the following information about process crash :
Detail Data
SIGNAL NUMBER : 11
USER'S PROCESS ID: 07968
FILE SYSTEM SERIAL NUMBER : 10
INODE NUMBER : 28773
CORE FILE NAME : /opt/itm/logs/exec/ud/core
PROGRAM NAME : kuddb2
STACK EXECUTION DISABLED
0
COME FROM ADDRESS REGISTER
CLI_csiSe 230
PROCESSOR ID
hw_fru_id: 1
hw_cpu_id: 3
ADDITIONAL INFORMATION
SQLConnec 6D0
SQLConnec 6B8
SQLDriver 440
SQLConnec 334
SQLConnec 530
__ct__13S 4E4
284
TakeSampl 2AC8
DriveData 26C
@@-82- 404
timeout__ 3C
2A8
Handler_b 1C
CTRA_time E0
_pthread_ E0
??

Environment


Diagnosing The Problem

Further analysis of the DB2 log (db2diag) highlights that kuddb2 process crashes when it tries
to perform an sqlconnect function and the target database is in quiesce status.

The quiesce is issued in example before starting an offline DB backup.

Resolving The Problem

This is not an ITM DB2 agent failure.It is a DB2 defect, and occurs only under specific circumstances.
If, into db2cli.ini file, you have set CurrentSchema, this triggers a communication round trip to the server side .
If during this communication the quiesce database with the force connections option is issued, as in the case of kuddb2 process, then that causes an error in the communication layer.
This nulls out the "half established" connection and this null connection is accessed once more prior to the return code check.. leading to the crash.

This is a problem occurring in DB2 v9.1 and DB2 v9.5 but it does not occur with DB2 9.7.
An APAR has been opened for DB2 9.5 : IC87545.
No fix will be delivered for 9.1 as it is out of support.
From ITM DB2 agent perspective, you can also use the following workaround :
The environment variable DB2CLIINIPATH can be used to override
the default and specify a different location for the db2cli.ini file.
.
1) Create a new .ini file,in example call it db2cli_kuddb2.ini and copy the content from the original one.
2) Remove the database specific entries and save the file.
3) Set the following environment variable before starting the DB2 monitoring agent :
.
export DB2CLIINIPATH=$HOME/sqllib/cfg/db2cli_for_kuddb2.ini
.

This should help circumventing the problem.

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Product Synonym

IBM Tivoli Monitoring DB2 Agent V6.2.2

Document Information

Modified date:
17 June 2018

UID

swg21617714