Managing Serviceguard Extension for SAP on Linux (IA64 Integrity and x86_64), April 2009

NOTE: After a failover, the liveCache instance will only be recovered to the state referenced in
LCSTARTMODE.
The behavior of the liveCache service monitoring script is independent from the setting of LCSTARTMODE.
The monitoring script will always monitor the vserver process. It will start to monitor if liveCache is in WARM
state, as soon as it reaches WARM state for the first time.
The LCMONITORINTERVAL variable specifies how often the monitoring polling occurs (in sec.)
liveCache installation Step: LC200
You can optionally handle SAP ABAP Application Servers with a liveCache package.
Refer to Chapter 3 - Serviceguard Extension for SAP on Linux Configuration for more information on the
usage of the parameters ASSID, ASHOST, ASNAME, ASNR, ASTREAT and ASPLATFORM
liveCache installation Step: LC205
Distribute the content of ${SGCONF}/<LCSID> to all cluster nodes on which the liveCache should be able
to run.
Service Monitoring
SAP recommends the use of service monitoring in order to evaluate the availability of liveCache processes.
The Serviceguard service monitor, provided with Serviceguard Extension for SAP on Linux, periodically
checks the availability and responsiveness of the liveCache system. The sanity of the monitor will be ensured
by standard Serviceguard functionality.
The liveCache monitoring program is shipped with Serviceguard Extension for SAP on Linux as the saplc.mon
file. The monitor runs as a service attached to the lc<LCSID> Serviceguard package.
If the monitor recognizes the liveCache to be unavailable, it will try to restart liveCache on the node it is
currently running. If this does not succeed, the runtime operating system resources of liveCache are cleaned
up and another local restart attempt is made. If the liveCache instance still cannot be started, Serviceguard
will switch the package and try to restart on another cluster node.
Monitoring begins with package startup. At this point, the monitor will make sure, that liveCache is working
only up to the point that is specified in LCSTARTMODE. For example, if LCSTARTMODE=OFFLINE is set in
file sap.config, only the vserver processes will be part of the monitoring. Still, the monitor detects any manual
state change of liveCache. By subsequent manual operations, liveCache will be entering cold state and
finally warm state, which the monitor automatically detects. As soon as the liveCache reaches the warm
state once, the monitoring increases its internal monitoring level to the same state.
As with any Serviceguard Extension for SAP on Linux package, the (lc) package will skip any SAP specific
startup steps when during startup a file called debug is found in either ${SGCONF}/<LCSID>/debug or
${SGCONF}/debug. When the debug file is found only the liveCache specific volumes will be mounted
and a virtual IP address is set. This is useful for debugging purposes to allow access to the logfiles placed
on shared logical volumes if a package does not start up to its full extent. The lc monitor is started regardless
of the availability of a debug file. The monitor will detect the existence of the file and will enter a pause
mode until it is removed. This is valid not only during package startup, but also at runtime. As a consequence,
the monitoring of a fully started package will be paused by the global debug file.
NOTE: Activation of pause mode, state changes of liveCache and liveCache restart attempts get permanently
logged into the standard package logfile ${SGCONF}/<LCSID>/lc<LCSID>.control.script.log.
The monitor can also be paused by standard administrative tasks that use the administrative tools delivered
by SAP. Stopping the liveCache using the SAP lcinit shell command or the APO LC10 transaction will
send the monitoring into pause mode. This prevents unwanted package failovers during liveCache
administration. Restarting the liveCache in the same way will also trigger reactivation of the monitoring. The
MaxDB Database Manager GUI is not yet cluster-aware and must not be used to stop liveCache in combination
with Serviceguard.
liveCache installation Step: LC210
Log in as <lcsid>adm on the primary node that has the shared logical volumes mounted.
Serviceguard Extension for SAP on Linux Package Configuration 115