This chapter provides information to assist in troubleshooting the DB2 Query Patroller server and describes common problems that may be encountered.
DB2 Query Patroller is composed of components that run on the DB2 Query Patroller server, and components that run on the DB2 Query Patroller client. The client does not communicate directly with the server. DB2 Query Patroller uses DB2 tables to pass information between the client and the server. For this reason an administrator or operator needs to be able to distinguish between DB2 failures and DB2 Query Patroller failures.
Refer to the Troubleshooting Guide if a problem or system failure is suspected to have originated from DB2.
The DB2 Query Patroller server maintains a system error log named syserr.log in the path referenced by the environment variable IWMLOG. This file contains diagnostic information for the DB2 Query Patroller server and may explain the cause of the system failure.
| Note: | DB2 Query Patroller agents should be configured to log their diagnostic information to a unique location. This will assist in determining where the error originated. |
If the DB2 database manager configuration parameter DIAGLEVEL is set to 4, all SQLCAs with a negative SQLCODE will be dumped to the diagnostic log. This information is useful when trying to determine why the DB2 Query Patroller server failed when attempting to access DB2.
On a properly functioning DB2 Query Patroller server, the following processes will be active:
An DB2 Query Patroller agent will have the following processes active:
| Note: | Other DB2 Query Patroller processes are transitory and will be started and stopped as required. |
If any of these processes have quit before completion, the DB2 Query Patroller system should be restarted. This process should be performed by systematically shutting down all DB2 Query Patroller agents followed by the DB2 Query Patroller server. The DB2 Query Patroller system can then be restarted by bringing up the server first, followed by the DB2 Query Patroller agents.
Under extreme circumstances, it may be necessary to generate a detailed DB2 Query Patroller server trace file to send to IBM support. In order to enable tracing, start the DB2 Query Patroller server or agent and implementing the trace option. More specifically, for the DB2 Query Patroller server specify iwm start all trace, and for an DB2 Query Patroller agent specify iwm start agent trace. The detailed trace will be written to the syserr.log file in the path specified by the DB2 profile variable IWMLOG. The trace results will continually be written to the log until DB2 Query Patroller is stopped and restarted without the tracing option.
| Note: | This file can grow quickly and should reside on a file system with a large amount of free disk space. |
DB2 Query Patroller is also integrated with DB2 trace. The IBM service organization may request a DB2 trace in order to help identify and localize a problem. Refer to the Troubleshooting Guide for details on how to perform a DB2 trace.