MQ monitoring agent uses MQ APIs to run PCF commands to gather data from WMQ.
The PCF commands are sent to the WebSphere MQ Command Server for their execution.
On the MQ side, the process which is directly associated with the command processing is "amqpcsea“ (which could be considered as the backend of the "command server").
Once the commands are executed the results are returned to the MQ monitoring agent via the KMQ.IRA.REPLY.QUEUE (or the equivalent temp and dynamic queue if it is not created).
As we said, MQ agent use MQ APIs to run PCF commands to gather data from WMQ.
These are the APIs used.
Connecting and disconnecting from the queue manager (MQCONN or MQCONNX, MQDISC)
Opening and closing a queue (MQOPEN, MQCLOSE)
Reading a message from a queue (MQGET)
Writing a message to a queue (MQPUT)
Writing a single message to a queue with an implicit open and close of the queue (MQPUT1)
Requesting or setting attributes of a queue manager object such as a queue (MQINQ, MQSET)
Beginning a unit of work (MQBEGIN)
Committing or backing out changes (MQCMIT, MQBACK)
They can be seen from RAS1 log file when KMQ ALL is set