TS/MP 2.5 System Management Manual

Detecting Problems
These factors might cause the PATHMON process to be busy at times other than startup and
shutdown:
• Poor configuration
• Creating and deleting links
• Gathering statistics and information
• Logging errors
• Failures
Poor Configuration
If a link manager, such as a ACS subsystem processes, or TCP, cannot establish communication
with a server process, the link manager indicates this situation to the screen program or Pathsend
requestor, and the PATHMON process writes an error message to the log files. If you experience
such a failure, you likely need to review your configuration. You might have to increase the
configuration size to handle the load, or a server class naming error might occur.
Creating and Deleting Links
If the PATHMON process is configured so that it is constantly creating and deleting links, it can
become the busiest process in the processor.
The PATHMON process can also become busy creating and deleting links if an application
repeatedly sends Pathsend requests to a frozen server class, and the ACS subsystem processes
has no links to that server class. The ACS subsystem processes repeatedly ask the PATHMON
process for a link to the frozen server class, then returns the link when the server is found to be
frozen. This problem can be resolved if the application, when notified that the server class is frozen,
waits a given period of time before trying again. For more information on configuring for optimum
link management, see “Configuring Links for Optimum Performance” (page 66).
Gathering Statistics and Information
The processor cost to maintain statistics is low. However, repeated reporting on statistics (especially
with the DETAIL option) or configuration information can impose an added burden on the
PATHMON process and the processor.
Logging Errors
The PATHMON process is responsible for all error logging. Delays in logging errors or status
messages can adversely affect the performance of the PATHMON environment.
You must review the log file and understand what causes each of the errors. In a well-designed,
well-configured PATHMON environment, the log might be empty or nearly so. Occasional errors
do not exact a large penalty. However, a poor configuration—for example, one that might cause
processes to frequently start and stop—can cause a performance degradation just in the logging
of the process status.
Failures
For large systems in which the PATHMON process manages numerous links, this events can cause
performance problems:
• processor failure
• Network failures
• A TCP going down (Pathway/iTS environment only)
• Server process failure
102 Maintaining a PATHMON Environment