TS/MP System Management Manual (G06.24+, H06.03+)

Maintaining a PATHMON Environment
NonStop TS/MP System Management Manual—541819-001
5-26
Managing PATHMON Process Performance
A link manager will return a link to a server process when any of these situations occur:
The PATHMON process and Server Links
If a server process goes down, the operating system automatically informs the
PATHMON process that owns that server class. The PATHMON process then
dissolves all links to that server process by sending a message to all LINKMON
processes with established links to that server process.
Because servers are (usually) coded to stop themselves when all openers have closed
them, system managers seldom need to worry about stopping servers.
Managing PATHMON Process Performance
The performance of the PATHMON process is critical to response time for applications
and management tasks.
Generally, in the production environment, the PATHMON process should be busy only
during startup and shutdown of the PATHMON environment. If the PATHMON
process is very busy at times other than startup and shutdown, you should take steps
to alleviate its workload.
Cause Action
A “DELETEDELAY” timer expires for a dynamic
link.
Returns the dynamic link.
An OPEN error occurs on a link. Returns the link.
An I/O error occurs on a link. (I/O errors include
timeouts caused by the SET SERVER TIMEOUT
value. Timeouts caused by the
SERVERCLASS_SEND_ timeout value are not
considered to be link errors.)
Returns all links for this server process,
allowing current I/O to complete.
The PATHMON process sends a server class
stop request.
Returns all links for this server process,
allowing current I/O to complete.
The PATHMON process sends a forced delink
request.
Returns all links to the server process,
allowing current I/O to complete.
The PATHMON process sends an external
shutdown notification
Deletes all links owned by that
PATHMON process, allowing current I/O
to complete. Consequently, no links are
returned to the PATHMON process.
The PATHMON process returns an unexpected
I/O error or close message, or the link manager
detects a message protocol error.
Deletes all links owned by that
PATHMON process, allowing current I/O
to complete. Consequently, no links are
returned to the PATHMON process.
A link manager gets an error trying to
communicate with the PATHMON process
Deletes all links owned by that
PATHMON process, allowing current I/O
to complete. Consequently, no links are
returned to the PATHMON process.