TS/MP System Management Manual (H06.05+, J06.03+)

Maintaining a PATHMON Environment
HP NonStop TS/MP System Management Manual—541819-007
5-28
Detecting Problems
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Failures
Poor Configuration
If a link manager, such as a LINKMON process, ACS subsystem processes, or TCP,
cannot establish communication with a server process, the link manager indicates this
situation to the screen program or Pathsend requester, 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. The configuration size may need to be increased to
handle the load, or there may be a server class naming error.
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
LINKMON process or ACS subsystem processes has no links to that server class. The
LINKMON process or 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.
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 its 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 should examine the log file and understand what causes each of the errors. In a
well-designed, well-configured PATHMON environment, the log should be empty or
nearly so. Occasional errors do not exact a large penalty. However, a poor
configuration—for example, one that causes may 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:
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processor failure