ServerNet Cluster Manual

Managing a ServerNet Cluster
ServerNet Cluster Manual—520575-003
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When a System Joins a ServerNet Cluster
2. Then the ServerNet cluster monitor process checks the configuration of its
associated ServerNet cluster (SCL) subsystem SUBSYS object:
•
If the SUBSYS object is configured with a STARTSTATE attribute set to
STOPPED—which is the default—the ServerNet cluster monitor process waits
for an SCF START SUBSYS $ZZSCL command before starting ServerNet
cluster services and joining the system to the ServerNet cluster.
•
If the SUBSYS object is configured with a STARTSTATE attribute set to
STARTED, the ServerNet cluster monitor process automatically starts
ServerNet cluster services and joins the system to the ServerNet cluster.
3. Once ServerNet cluster services on the local system are started, the ServerNet
cluster monitor process establishes ServerNet connections with all other systems
in the ServerNet cluster that are in the STARTED or STARTING states.
4. If the Expand-over-ServerNet line-handler processes are configured and are in the
STARTED state, Expand connectivity over ServerNet with the other systems in the
ServerNet cluster is established.
5. When the ServerNet cluster startup is completed, the ServerNet cluster monitor
process has a list of all systems known to be in the ServerNet cluster, and
ServerNet connections are established with each system.
6. If ServerNet connection attempts fail or if successful connections subsequently fail,
periodic attempts are made to establish or reestablish the connection. Failures and
successful reconnections are logged to the event log. Failures to connect are
logged as path or other failures. In addition, each ServerNet Cluster subsystem
state change (to STARTING, then to STARTED) is logged. If no other systems are
discovered, that fact is also logged.
Note. For detailed information about the SCL subsystem SUBSYS object summary states
and the STARTSTATE attribute, see Section 8, SCF Commands for SNETMON and the
ServerNet Cluster Subsystem.
Do not confuse the PROCESS object STARTMODE attribute with the SUBSYS object
STARTSTATE attribute:
•
The STARTMODE attribute controls the way the Persistence Manager $ZPM starts
the ServerNet cluster monitor process after a system load.
•
The STARTSTATE attribute controls the way the ServerNet cluster monitor process
joins the system to the ServerNet cluster.