User's Manual

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 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 customer-defined or external run scripts of the VM guest package on the VM Host
cluster.
The application server cmappserver responds to requests from the application manager process
cmappmgr, running on the VM Host. The requests are to execute a specified process on the VM
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 guest that provides connections for up to 30 simultaneous processes that can
be monitored by cmappmgr.
In Figure 2 (page 15), app1 and app2 are two applications running within a VM guest that are
monitored by HP Serviceguard running on a VM Host cluster. The cmappserver daemon process,
running in the VM 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 guest package. The VM guest
service, which is part of the SG IVS toolkit, monitors the overall VM guest.
Figure 3 Failure of a monitored VM guest application
If a monitored application in the VM guest fails, for example, app 1 as shown in Figure 3 (page
16), 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 on the VM guest. The number of
times HP Serviceguard attempts to restart cmappmgr and the VM guest application is defined by
16 Configuring guest application monitoring service