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

Relocatable IP addresses can be used as of SAP kernel 6.40. Older releases use local hostnames in profile
names and startup script names. Renamed copies of the files or symbolic links had to be created to overcome
this issue.
The SAP Spool Work Process uses the SAP Application Server name as the destination for print formatting.
Use the relocatable name if you plan to use Spool Work processes with your Central Instance. In the case
of a failover the SAP print system will continue to work.
NOTE: Any running print job at the time of the failure will be canceled and needs to be reissued manually
after the failover. To make the SAP print spooler highly available on the Central Instance, set the destination
of the printer to <relocatible_ci_name>_<SID>_<nr>using the SAP transaction SPAD. Print all time
critical documents via the high available spool server of the Central Instance.
Print requests to other spool servers stay in the system after failure until the host is available again and the
spool server has been restarted. These requests can be moved manually to other spool servers if the failed
server is unavailable for a longer period of time.
Batch jobs can be scheduled to run on a particular instance. Generally speaking, it is better not to specify
a destination host at all. Sticking to this rule, the batch scheduler chooses a batch server which is available
at the start time of the batch job. However, if you want to specify a destination host, specify the batch server
running on the highly available Central Instance. The application server name and the hostname (which is
retrieved from the Message Server) are stored in the batch control tables TBTCO, TBTCS,.... In case the batch
job is ready to run, the application server name is used to start it. Therefore, when using the relocatable
name to create the Application Server name for the instance, you do not need to change batch jobs after a
switchover. This is true even if the hostname which is also stored in the above tables, differs.
Plan to use saplogon to application server groups instead of saptemu/sapgui to
individual application servers. When logging on to an application server group with two or
more application servers, the SAP user does not need a different login procedure if one of the application
servers of the group fails. Also, using login groups provides workload balancing between application servers.
Within the CCMS you can define operation modes for SAP instances. An operation mode defines a resource
configuration. It can be used to determine which instances are started and stopped and how the individual
services are allocated for each instance in the configuration. An instance definition for a particular operation
mode consists of the number and types of Work processes as well as Start and Instance Profiles. When
defining an instance for an operation mode you need to enter the hostname and the system number of the
application server. By using relocatable names to fill in the hostname field, the instance will - after a failover
and under control of CCMS - continue to work without a change
NOTE: If an instance is running on the standby node in normal operation and is stopped during the
switchover.
Only configure the update service on a node for SAP application services running on the same node. The
result is, the remaining servers, running on different nodes, are not affected by the outage of the update
server. However, if the update server is configured to be responsible for application servers running on
different nodes, any failure of the update server leads to subsequent outages at these nodes. Therefore
configure the update server on a clustered instance. The use of local update servers should only be considered,
if performance issues require it.
Serviceguard Extension for SAP on Linux Administration Aspects
Serviceguard Extension for SAP on Linux needs some additional information about the configuration of an
SAP environment. This information is stored in the file ${SGCONF}/<SID>/sap.config. For more
complicated cases additional configuration files ${SGCONF}/<SID>/sap<pkg_name>.config can be
created. A sap<pkg_name>.config file is sometimes used to create a package specific SECTION TWO
of the sap.config file in order to achieve proper SAP application server handling. In principle this file
serves the same purpose and has the same syntax as the generic sap.configfile.
It is very important that the information in this file is consistent with the way your system is configured. This
file must be available on all nodes of the cluster. Under normal operation there is no need to modify this
file. Comments are provided within the file and should be self-explanatory. The following administration
activities are possible but they must be accompanied by an adaptation of the sap.config file on all cluster
nodes:
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