In this architecture, the Application Managers and the Application Servers communicate via SSL connections using the JSSE.
The Application Manager cmappmgr initiates and maintains a connection with the application server process cmappserver in the monitored VM or vPar guest using TCP or IP port 5315 for communications. Its primary function is to launch the specified command and monitor the execution of the same by:
•Sending requests to cmappserver, to execute specified processes.
•Sending periodic polling messages to cmappserver, to check the status of the monitored process.
cmappmgr also performs the following functions:
•Writes the error messages to Serviceguard package log file and syslog.
•Exits with a reason code from the terminating monitored process.
•Exits when monitored process exits.
cmappmgr can be configured to run either as an HP Serviceguard monitored service or can be invoked by the
The application server cmappserver responds to requests from the application manager process cmappmgr, running on the VM or vPar Host. The requests are to execute a specified process on the VM or vPar guest, periodically check the status of the monitored process, and return an exit code when the process terminates. The cmappserver is a light weight daemon (approximately 36k) running on the monitored VM or vPar guest that provides connections for up to 30 simultaneous processes that can be monitored by cmappmgr.
In Figure 2 (page 20), app1 and app2 are two applications running within a VM or vPar guest that are monitored by HP Serviceguard running on a VM or vPar Host cluster. The cmappserver daemon process, running in the VM or vPar guest, provides communication connections with two cmappmgr processes. One communication connection is provided for each monitored application
-app1 and app2, running as HP Serviceguard services that are monitored by the VM or vPar guest package. The VM or vPar guest service, which is part of the SG IVS toolkit, monitors the overall VM or vPar guest.
Figure 3 Failure of a monitored VM or vPar guest application
If a monitored application in the VM or vPar guest fails, for example, app1 as shown in Figure 3 (page 21), this event and the exit code of the application is communicated to its corresponding cmappmgr process running on the VM Host. If the cmappmgr process for the monitored application exits, HP Serviceguard restarts cmappmgr. It also restarts the application
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