NET/MASTER Management Services (MS) System Management Guide

Running BK, EM, and NC Processes as Process Pairs
Configuring the Processing Environment
115414 NonStop NET/MASTER MS System Management Guide 11–51
The PARAM PROCESSCPU command is not applicable for dynamic processes. For a
dynamic BK, EM, or NC process started as a process pair, the primary process creates
the backup process in the next higher-numbered CPU (selected in a round-robin
fashion) relative to the CPU in which the primary process is currently executing. If no
CPU is available, the primary process creates the backup process when the appropriate
CPU becomes available. Meanwhile, the primary process runs without a backup
process (and will not survive a failure).
Recovering After BK, EM,
or NC Process Pair Failure
If a primary BK, EM, or NC process fails, the backup takes over as the primary process
and starts a new backup process. If a persistent NCL process is running in the BK,
EM, or NC process, the BK, EM, or NC process restarts the NCL process.
If a backup BK, EM, or NC process fails, the primary process restarts the backup
process. If a persistent NCL process is running in the BK, EM, or NC process, the NCL
process is unaffected and continues executing.
If both the primary and backup BK, EM, or NC processes fail, the NCP restarts the BK,
EM, or NC process as a persistent process. The BK, EM, or NC process does not
automatically start running as a process pair; the BK, EM, or NC process stops running
as a persistent process and starts running as a process pair on the first occasion that an
NCL process running in an NCL processing environment within the BK, EM, or NC
process starts a persistent NCL process. If a persistent NCL process was running in
the failed BK, EM, or NC process pair, the new BK, EM, or NC process does not
automatically restart the NCL process. The failed persistent NCL process must be
restarted again by the NCL process that originally started it.
BK, EM, and NC Process
Pairs in the NonStop
NET/MASTER MS
Processing Environment
Use of persistent NCL increases the variety of possible NonStop NET/MASTER MS
processes in the NonStop NET/MASTER MS processing environment. Figure 11-5
shows the possible NonStop NET/MASTER MS processes. It shows the four process
types: NCP, GMM processes, security exit processes, and application processes. For
application processes, it shows the five process classes: BK, EM, IS, MS, and NC. For
each process class, it shows whether you can start static processes, dynamic processes,
static process pairs, or dynamic process pairs.