MC/ServiceGuard Package Concepts

Specific files are required to build MC/ServiceGuard packages. The files required apply to both the SGeSAP one package model and two package model. Figure 1-5 “Configuration Files Needed to Build Cluster” illustrates the required configuration files, and the questions they answer, for an SGeSAP application package in MC/ServiceGuard.

Figure 1-5 Configuration Files Needed to Build Cluster

Figure 1-6 “Control Files Containing Runtime Logic” illustrates the required control files for an SGeSAP application package in MC/ServiceGuard.

Figure 1-6 Control Files Containing Runtime Logic

Extension Files for the One Package Model

In the one package model, the SAP R/3 functionality—database and central instance—along with the highly available NFS server are all been placed in one MC/ServiceGuard package.

The SGeSAP scripts of the one package concept are organized as follows:

/etc/cmcluster/sapr3.conf—cluster configuration file of MC/ServiceGuard.
/etc/cmcluster/<SID>/dbci.conf—package configuration file based on the current MC/ServiceGuard configuration file.
/etc/cmcluster/<SID>/dbci.cntl—package control file based on the current MC/ServiceGuard file. It must call <SID>/sapdbci.cntl in the customer_defined_[run|halt]_cmds section.
/etc/cmcluster/<SID>/sap.conf—contains the actual configuration and options of the SGeSAP Integration Scripts. It needs to be customized.
/etc/cmcluster/sap.functions—contains all standard runtime logic used by one package and two package configurations. Do not modify this file!
/etc/cmcluster/customer.functions—contains all functions which can be modified for special setups. This file may also contain your own additional functions. If you have to change functions in /etc/cmcluster/sap.functions, copy them over to /etc/cmcluster/customer.functions and modify them there. Never modify /etc/cmcluster/sap.functions itself. Any function provided in customer.functions overrides its equivalent in sap.functions.
/etc/cmcluster/<SID>/sapdbci.cntl—contains database and SAP R/3 specific control logic. This file is valid for one package configurations only. Sources include <SID>/sap.conf, customer.functions, and sap.functions.

Use the one pkg concept for all configurations where you can put the database and central instance on one node and have an equally sized node as a backup. During normal operation, backup nodes can be used as an idle standby, application server host, or test system.

If you are planning to distribute the database and central instance on two nodes in the near future apply the two package concept.

Extension Files For the Two-Package Model

In the two package model, the SAP R/3 functionality is separated into two MC/ServiceGuard packages. One for the database (DB) and the other for the SAP R/3 central instance (CI). The database package contains the filesystems for the NFS mount points. The SGeSAP scripts of the two package concept are organized as follows:

/etc/cmcluster/sapr3.conf—cluster configuration file of MC/ServiceGuard.
/etc/cmcluster/<SID>/db.conf—database package configuration file based on the current MC/ServiceGuard configuration file. The provided file is for reference only, create your own.
/etc/cmcluster/<SID>/ci.conf—central instance package configuration file based on the current MC/ServiceGuard configuration file. The provided file is for reference only, create your own.
/etc/cmcluster/<SID>/db.cntl—database package control file based on the current MC/ServiceGuard configuration control file. It must call <SID>/sapdb.cntl in the customer_defined_[run|halt]_cmds sections.
/etc/cmcluster/<SID>/ci.cntl—central instance package control file based on the current MC/ServiceGuard control file. It must call <SID>/sapdbci.cntl in the customer_defined_[run|halt]_cmds sections.
/etc/cmcluster/<SID>/sap.conf—contains the actual configuration and options of the Integration Scripts. It needs to be customized.
/etc/cmcluster/sap.functions—contains all standard runtime logic used by one package and two package configurations. Do not modify this file!.
/etc/cmcluster/customer.functions—contains all functions which can be modified for special setups. This file may also contain your own additional functions. If you have to change functions in /etc/cmcluster/sap.functions copy them over to /etc/cmcluster/customer.functions and modify them there. Never modify /etc/cmcluster/sap.functions itself. Any function provided in customer.functions overrides its equivalent in sap.functions.
/etc/cmcluster/<SID>/sapci.cntl—contains SAP R/3 specific control logic. This file is valid for a two package configuration only. Sources include <SID>/sap.conf, customer.functions, and sap.functions.
/etc/cmcluster/<SID>/sapdb.cntl—contains database control logic. This file is valid for a two package configuration only. Sources include <SID>/sap.conf, customer.functions, and sap.functions.

Extension Files for an Application Server Package

The creation of an Application server package only makes sense if a one-package or two-package model has already been implemented. The needed Application server files are organized as follows:

/etc/cmcluster/<SID>/ap<SID><INSTNR>.conf—capplication server package configuration file based on the standard MC/ServiceGuard configuration file.
/etc/cmcluster/<SID>/ap<SID><INSTNR>.cntl—application server package control file based on the standard MC/ServiceGuard control file. It must call /etc/cmcluster/<SID>/sapap.cntl in the customer_defined_[run|halt]_cmds section.
/etc/cmcluster/<SID>/sapap.cntl— contains SAP Application server specific control logic. This file applies to the an Application server package only and must not be edited.

MC/ServiceGuard Package Concepts

Technical documentation

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Extension Files for the One Package Model

Extension Files For the Two-Package Model

Extension Files for an Application Server Package