PeopleTools 8.48 Process Scheduler Behaviour

Things change, and I recently got caught out by one of those changes.

In PeopleTools 8.4x, the Process Scheduler became a proper Tuxedo domain. By default, it is configured to run Application Engine server processes (PSAESRV). These are persistent Tuxedo server processes that handle Application Engine requests. This change was introduced to help CRM systems that typically run a very large number of Application Engine programs. Because the server process is persistent it saves the overhead of starting a new Application Engine process. An obvious side effect of this change in architecture is that if you shut the Process Scheduler down, it terminates the PSAESRV processes, and cancels any Application Engine program that is running.

You can choose to configure the Process Scheduler without PSAESRV processes, and it will start individual PSAE processes for each Application Engine request.

In previous versions of PeopleTools, it was possible to shut the Process Scheduler down and any running processes (except PSAESRVs) would continue to run. This is not the case in PeopleTools 8.48. On shutdown, the Process Scheduler attempts to cancel the PSAE process. If it is not successful the status of the process goes to Error, but the process continues to run.

PSPRCSRV.7150 (0) [...](3)    Server: PSUNX checking status...
PSPRCSRV.7150 (0) [...](3)    Server action mode: Ok (looking for requests)
PSPRCSRV.7150 (0) [...](3)    Server: PSUNX looking for work
PSPRCSRV.7150 (0) [...](3)    Checking Process cancels...
PSPRCSRV.7150 (0) [...](3)    Process 69 is still running as Session ID 7552
PSPRCSRV.7150 (0) [...](3)                 Application Engine       :           1:3
PSPRCSRV.7150 (0) [...](0)    Server is shutting down

So, the Process Scheduler knows that process 69 is still running but continues to shutdown

PSPRCSRV.1360 (0) [...](1) =================================Error===============================
PSPRCSRV.1360 (0) [...](1)    Process 69 is marked 'Initiated' or 'Processing' but can not detect status of PID
PSPRCSRV.1360 (0) [...](3)    Updating process instance's status to Error.
PSPRCSRV.1360 (0) [...](2)         Process Name: PSQUERY
PSPRCSRV.1360 (0) [...](2)         Process Type: Application Engine
PSPRCSRV.1360 (0) [...](2)         Session Id:   7552
PSPRCSRV.1360 (0) [...](2) =====================================================================
PSPRCSRV.1360 (0) [...](3)   Number of requests removed from Task Active List:  1
PSPRCSRV.1360 (0) [...](3)    Server action mode: Initializing

But when it starts up again it cannot detect the PID of the process, and so it marks the status as 3 (Error).

I'm not sure exactly when this change was introduced, but this is the first time I have encountered it.