Installing and Configuring Sun Cluster HA for SAP liveCache

This page contains the procedures on how to install and configure Sun Cluster HA for SAP liveCache.

This page contains the following procedures.

• How to Prepare the Nodes
• How to Install and Configure SAP liveCache
• How to Enable SAP liveCache to Run in a Cluster
• How to Verify the SAP liveCache Installation and Configuration
• How to Install the Sun Cluster HA for SAP liveCache Packages
• How to Register and Configure Sun Cluster HA for SAP liveCache
• How to Verify the Sun Cluster HA for SAP liveCache Installation and Configuration

Top

Sun Cluster HA for SAP liveCache Overview

Use the information in this section to understand how Sun Cluster HA for SAP liveCache makes SAP liveCache highly available.

For conceptual information on failover and scalable services, see the .Sun Cluster concepts documentation

To eliminate a single point of failure in an SAP Advanced Planner & Optimizer (APO) System, Sun Cluster HA for SAP liveCache provides fault monitoring and automatic failover for SAP liveCache and fault monitoring and automatic restart for SAP xserver. The following table lists the data services that best protect SAP Supply Chain Management (SCM) components in a Sun Cluster configuration. Figure 1 also illustrates the data services that best protect SAP SCM components in a Sun Cluster configuration.

Protection of SAP liveCache Components

Protection of SAP liveCache Components

Top

Installing and Configuring Sun Cluster HA for SAP liveCache

Table 2 lists the tasks for installing and configuring Sun Cluster HA for SAP liveCache. Perform these tasks in the order that they are listed.

Task Map: Installing and Configuring Sun Cluster HA for SAP liveCache

Top

Planning the Sun Cluster HA for SAP liveCache Installation and Configuration

This section contains the information you need to plan your Sun Cluster HA for SAP liveCache installation and configuration.

Note If you have not already done so, read your SAP documentation before you begin planning your Sun Cluster HA for SAP liveCache installation and configuration because your SAP documentation includes configuration restrictions and requirements that are not outlined in Sun Cluster documentation or dictated by Sun Cluster software.

Top

Configuration Requirements

Caution Your data service configuration might not be supported if you do not adhere to these requirements.

Use the requirements in this section to plan the installation and configuration of Sun Cluster HA for SAP liveCache. These requirements apply to Sun Cluster HA for SAP liveCache only. You must meet these requirements before you proceed with your Sun Cluster HA for SAP liveCache installation and configuration.

For requirements that apply to all data services, see Sun Cluster data services collection.

• Use an SAP liveCache version 7.4 or higher.
• Configure SAP xserver so that SAP xserver starts on all nodes that the SAP liveCache resource can failover to. To implement this configuration, ensure that the nodelist of the SAP xserver resource group and the SAP liveCache resource group contain the same nodes. Also, the value of desired_primaries and maximum_primaries of the SAP xserver resource must be equal to the number of nodes listed in the nodelist parameter of the SAP liveCache resource. For more information, see How to Register and Configure Sun Cluster HA for SAP liveCache.

Top

Standard Data Service Configurations

Use the standard configurations in this section to plan the installation and configuration of Sun Cluster HA for SAP liveCache. Sun Cluster HA for SAP liveCache supports the standard configurations in this section. Sun Cluster HA for SAP liveCache might support additional configurations. However, you must contact your Sun service provider for information on additional configurations.

Figure 2 illustrates a four-node cluster with SAP APO Central Instance, APO application servers, a database, and SAP liveCache. APO Central Instance, the database, and SAP liveCache are configured as failover data services. APO application servers and SAP xserver can be configured as scalable or failover data services.

Four-Node Cluster

Top

Configuration Considerations

Use the information in this section to plan the installation and configuration of Sun Cluster HA for SAP liveCache. The information in this section encourages you to think about the impact your decisions have on the installation and configuration of Sun Cluster HA for SAP liveCache.

• Install SAP liveCache on its own global device group, separate from the global device group for the APO Oracle database and SAP R/3 software. This separate global device group for SAP liveCache ensures that the SAP liveCache resource can depend on the HAStoragePlus resource for SAP liveCache only.* If you want to run SAP xserver as any user other than user root, create that user on all nodes on which SAP xserver runs, and define this user in the Xserver_User extension property. SAP xserver starts and stops based on the user you identify in this extension property. The default for this extension property is user root.
• Configure SAP xserver as a failover resource unless you are running multiple liveCache instances that overlap.

Top

Configuration Planning Questions

Use the questions in this section to plan the installation and configuration of Sun Cluster HA for SAP liveCache. Insert the answers to these questions into the data service worksheets in the Sun Cluster release notes documentation. See Configuration Considerations for information that might apply to these questions.

• What resource groups will you use for network addresses and application resources and the dependencies between them?
• What is the logical hostname (for SAP liveCache resource) for clients that will access the data service?
• Where will the system configuration files reside?
  
  See Sun Cluster data services collection for the advantages and disadvantages of placing the SAP liveCache binaries on the local file system as opposed to the cluster file system.

Top

Preparing the Nodes and Disks

This section contains the procedures you need to prepare the nodes and disks.

How to Prepare the Nodes

Use this procedure to prepare for the installation and configuration of SAP liveCache.

1. Become superuser on all of the nodes.
2. Configure the /etc/nsswitch.conf file.
   1. On each node that can master the SAP liveCache resource, include one of the following entries for group, project, an passwd database entries in the /etc/nsswitch.conf file.

      database:
      database: files
      database: files [NOTFOUND=return] nis
      database: files [NOTFOUND=return] nisplus

   2. On each node that can master the SAP liveCache resource, ensure that files appears first for the protocols database entry in the /etc/nsswitch.conf file.
      
      Example:

      protocols: files nis

      Sun Cluster HA for SAP liveCache uses the su - user command and the dbmcli command to start and stop SAP liveCache.
      
      The network information name service might become unavailable when a cluster node's public network fails. Implementing the preceding changes to the /etc/nsswitch.conf file ensures that the su(1M) command and the dbmcli command do not refer to the NIS/NIS+ name services.

Top

Installing and Configuring SAP liveCache

This section contains the procedures you need to install and configure SAP liveCache.

How to Install and Configure SAP liveCache

Use this procedure to install and configure SAP liveCache.

1. Install and configure SAP APO System.
   
   See Sun Cluster data services collection for the procedures on how to install and configure SAP APO System on Sun Cluster software.
2. Install SAP liveCache.

   Note Install SAP liveCache by using the physical hostname if you have not already created the required logical host.

   For more information, see your SAP documentation.

3. Create the .XUSER.62 file for the SAP APO administrator user and the SAP liveCache administrator user by using the following command.

   # dbmcli -d LC-NAME -n logical-hostname -us user,passwd

   LC-NAME

   Uppercase name of SAP liveCache database instance

   logical-hostname

   Logical hostname that is used with the SAP liveCache resource

   Caution Neither SAP APO transaction LC10 nor Sun Cluster HA for SAP liveCache functions properly if you do not create this file correctly.

4. Copy /usr/spool/sql from the node, on which you installed SAP liveCache, to all the nodes that will run the SAP liveCache resource. Ensure that the ownership of these files is the same on all node as it is on the node on which you installed SAP liveCache.
   
   Example:

   # tar cfB - /usr/spool/sql | rsh phys-schost-1 tar xfB -

How to Enable SAP liveCache to Run in a Cluster

During a standard SAP installation, SAP liveCache is installed with a physical hostname. You must modify SAP liveCache to use a logical hostname so that SAP liveCache works in a Sun Cluster environment. Use this procedure to enable SAP liveCache to run in a cluster.

1. Create the failover resource group to hold the network and SAP liveCache resource.

   # scrgadm -a -g livecache-resource-group [-h nodelist]

2. Verify that you added all the network resources you use to your name service database.
3. Add a network resource (logical hostname) to the failover resource group.

   # scrgadm -a -L -g livecache-resource-group\ -l lc-logical-hostname [-n netiflist]

4. Enable the failover resource group.

   # scswitch -Z -g livecache-resource-group

5. Log on to the node that hosts the SAP liveCache resource group.
6. Start SAP xserver manually on the node that hosts the SAP liveCache resource group.

   # su - lc-nameadm
   # x_server start

   lc-name

   Lowercase name of SAP liveCache database instance

7. Log on to SAP APO System by using your SAP GUI with user DDIC.
8. Go to transaction LC10 and change the SAP liveCache host to the logical hostname you defined in Step 3.

   liveCache host: lc-logical-hostname

Top

Verifying the SAP liveCache Installation and Configuration

This section contains the procedure you need to verify the SAP liveCache installation and configuration.

How to Verify the SAP liveCache Installation and Configuration

Use this procedure to verify the SAP liveCache installation and configuration. This procedure does not verify that your application is highly available because you have not installed your data service yet.

1. Log on to SAP APO System by using your SAP GUI with user DDIC.
2. Go to transaction LC10.
3. Ensure that you can check the state of SAP liveCache.
4. Ensure that the following dbmcli command work as user _lc_name_adm.

   # dbmcli -d LC_NAME -n logical-hostname db_state# dbmcli -d LC_NAME -n logical-hostname db_enum

Top

Installing the Sun Cluster HA for SAP liveCache Packages

This section contains the procedure you need to install the Sun Cluster HA for SAP liveCache packages.

How to Install the Sun Cluster HA for SAP liveCache Packages

Use this procedure to install the Sun Cluster HA for SAP liveCache packages. You need the Sun Cluster 3.0 5/02 Agents CD-ROM to perform this procedure. This procedure assumes that you did not install the data service packages during your initial Sun Cluster installation.

1. Load the Sun Cluster 3.0 5/02 Agents CD-ROM into the CD-ROM drive.
2. Run the scinstall utility with no options.
   
   This step starts the scinstall utility in interactive mode.
3. Choose the Add Support for New Data Service to This Cluster Node menu option.
   
   The scinstall utility prompts you for additional information.
4. Provide the path to the Sun Cluster 3.0 5/02 Agents CD-ROM.
   
   The utility refers to the CD-ROM as the “data services cd.”
5. Specify the data service to install.
   
   The scinstall utility lists the data service that you selected and asks you to confirm your choice.
6. Exit the scinstall utility.
7. Unload the CD-ROM from the drive.

Top

Registering and Configuring the Sun Cluster HA for SAP liveCache

This section contains the procedures you need to configure Sun Cluster HA for SAP liveCache.

Top

Sun Cluster HA for SAP liveCache Extension Properties

Use the extension properties in Table 3 and Table 4 to create your resources. Use the following command line to configure extension properties when you create your resource.

Use the procedure in Sun Cluster data services collection to configure the extension properties if you have already created your resources. You can update some extension properties dynamically. You can update others, however, only when you create or disable a resource. The Tunable fields in Table 3 and Table 4 indicate when you can update each property. See Appendix A for details on all Sun Cluster properties.

Sun Cluster HA for SAP liveCache (SUNW.sap_xserver) Extension Properties

Sun Cluster HA for SAP liveCache (SUNW.sap_livecache) Extension Properties

How to Register and Configure Sun Cluster HA for SAP liveCache

Use this procedure to configure Sun Cluster HA for SAP liveCache as a failover data service for the SAP liveCache database and SAP xserver as a failover or scalable data service. This procedure assumes that you installed the data service packages. If you did not install the Sun Cluster HA for SAP liveCache packages as part of your initial Sun Cluster installation, go to How to Install the Sun Cluster HA for SAP liveCache Packages to install the data service packages. Otherwise, use this procedure to configure the Sun Cluster HA for SAP liveCache.

Caution Do not configure more than one SAP xserver resource on the same cluster because one SAP xserver serves multiple SAP liveCache instances in the cluster. More than one SAP xserver resource that runs on the same cluster causes conflicts between the SAP xserver resources. These conflicts cause all SAP xserver resources to become unavailable. If you attempt to start the SAP xserver twice, you receive an error message that says Address already in use.

1. Become superuser on one of the nodes in the cluster that will host the SAP liveCache resource.
2. Copy the lccluster file to the same location as the lcinit file.

   # cp /opt/SUNWsclc/livecache/bin/lccluster \
   /sapdb/LC-NAME/db/sap

   LC-NAME

   Uppercase name of SAP liveCache database instance

3. Edit the lccluster file to substitute values for put-LC_NAME-here and put-Confdir_list-here.

   Note The put-Confidir_list-here value exists only in the Sun Cluster 3.1 version.

   1. Open the lccluster file.

      # vi /sapdb/LC-NAME/db/sap/lccluster \
      LC_NAME="put-LC_NAME-here" \
      CONFDIR_LIST="put-Confdir_list-here"

      Note The CONFDIR_LIST=”put-Confdir_list-here entry exists only in the Sun Cluster 3.1 version.

   2. Replace put-LC_NAME-here with the SAP liveCache instance name. The SAP liveCache instance name is the value you defined in the Livecache_Name extension property.

      LC_NAME="liveCache-instance-name"

   3. Replace put-Confdir_list-here with the value of the Confidir_list extension property.

      Note This step is only for the Sun Cluster 3.1 version. Skip this step if you are running an earlier version of Sun Cluster.

      CONFDIR_LIST="liveCache-software-directory"

      Example:
      
      If the SAP liveCache instance name is LC1 and the SAP liveCache software directory is /sapdb, edit the lccluster script as follows.

      LC_NAME="LC1"
      CONFDIR_LIST="/sapdb" [Sun Cluster 3.1 version only]

4. Add the HAStoragePlus resource to the SAP liveCache resource group.

   # scrgadm -a -t SUNW.HAStoragePlus
   # scrgadm -a -j livecache-storage-resource -g livecache-resource-group \
   -t SUNW.HAStoragePlus -x filesystemmountpoints=mountpoint,... \
   -x globaldevicepaths=livecache-device-group

5. Enable the SAP liveCache storage resource.

   # scswitch -e -j livecache-storage-resource

6. Register the resource type for SAP liveCache database.

   # scrgadm -a -t SUNW.sap_livecache

7. Register the resource type for SAP xserver.

   # scrgadm -a -t SUNW.sap_xserver

8. Configure the SAP xserver as a scalable resource, completing the following substeps.
   1. Create a scalable resource group for SAP xserver. Configure SAP xserver to run on all the potential nodes that SAP liveCache will run on.

      Note Configure SAP xserver so that SAP xserver starts on all nodes that the SAP liveCache resources can fail over to. To implement this configuration, ensure that the nodelist parameter of the SAP xserver resource group contains all the nodes listed in the liveCache resource groups' nodelist. Also, the value of desired_primaries and maximum_primaries of the SAP xserver resource group must be equal to each other.

      # scrgadm -a -g xserver-resource-group \
      -y Maximum_primaries=value \
      -y Desired_primaries=value \
      -h nodelist

   2. Create an SAP xserver resource in this scalable resource group.

      # scrgadm -a -j xserver-resource \
      -g xserver-resource-group -t SUNW.sap_xserver

   3. Enable the scalable resource group that now includes the SAP xserver resource.

      # scswitch -Z -g xserver-resource-group

9. Register the SAP liveCache resource as follows.

   # scrgadm -a -j livecache-resource -g livecache-resource-group \
   -t SUNW.sap_livecache -x livecache_name=LC-NAME \
   -y resource_dependencies=livecache-storage-resource

10. Set up a resource group dependency between SAP xserver and SAP liveCache.

    # scrgadm -c -g livecache-resource-group \
    -y rg_dependencies=xserver-resource-group

11. Enable the liveCache failover resource group.

    # scswitch -Z -g livecache-resource-group

12. Are you running an APO application server on a node that SAP liveCache can fail over to?
    • If no, this step completes this procedure.
    • If yes, proceed to Step 9.
13. Is the scalable APO application server resource group already in an RGOffload resource's rg_to_offload list?

    # scrgadm -pvv | grep -i rg_to_offload | grep value:

    • If yes, this step completes this procedure.
    • If no, consider adding an RGOffload resource in the SAP liveCache resource group.
      
      This configuration enables you to automatically shut down the APO application server if the liveCache resource fails over to a node on which the APO application server was running.

Top

Verifying the Sun Cluster HA for SAP liveCache Installation and Configuration

This section contains the procedure you need to verify that you installed and configured your data service correctly.

How to Verify the Sun Cluster HA for SAP liveCache Installation and Configuration

Use this procedure to verify that you installed and configured Sun Cluster HA for SAP liveCache correctly. You need the information in the following table to understand the various states of the SAP liveCache database.

1. Log on to the node that hosts the resource group that contains the SAP liveCache resource, and verify that the fault monitor functionality works correctly.
   1. Terminate SAP liveCache abnormally by stopping all SAP liveCache processes.
      
      Sun Cluster software restarts SAP liveCache.

      # ps -ef|grep sap|grep kernel
      # kill -9 livecache-processes

   2. Terminate SAP liveCache by using the Stop liveCache button in LC10 or by running the lcinit command.
      
      Sun Cluster software does not restart SAP liveCache. However, the SAP liveCache resource status message reflects that SAP liveCache stopped outside of Sun Cluster software through the use of the Stop liveCache button in LC10 or the lcinit command. The state of the SAP liveCache resource is UNKNOWN. When the user successfully restarts SAP liveCache by using the Start liveCache button in LC10 or the lcinit command, the Sun Cluster HA for SAP liveCache Fault Monitor updates the resource state and status message to indicate that SAP liveCache is running under the control of Sun Cluster software.
2. Log on to SAP APO by using your SAP GUI with user DDIC, and verify that SAP liveCache starts correctly by using transaction LC10.
3. As user root, switch the SAP liveCache resource group to another node.

   # scswitch -z -g livecache-resource-group -h node2

4. Repeat Step 1 through Step 3 for each potential node on which the SAP liveCache resource can run.
5. Log on to the nodes that host the SAP xserver resource, and verify that the fault monitor functionality works correctly.
   
   Terminate SAP xserver abnormally by stopping all SAP xserver processes.

   # ps -ef|grep xserver
   # kill -9 xserver-process

Top

Understanding Sun Cluster HA for SAP liveCache Fault Monitors

Use the information in this section to understand Sun Cluster HA for SAP liveCache Fault Monitors. This section describes the Sun Cluster HA for SAP liveCache Fault Monitors' probing algorithm or functionality, states the conditions, messages, and recovery actions associated with unsuccessful probing, and states the conditions and messages associated with successful probing.

Top

Extension Properties

See Sun Cluster HA for SAP liveCache Extension Properties for the extension properties that the Sun Cluster HA for SAP liveCache Fault Monitors use.

Top

Monitor Check Method

A SAP liveCache resource Monitor_check method checks whether SAP xserver is available on this node. If SAP xserver is not available on this node, this method returns an error and rejects the failover of SAP liveCache to this node.

This method is needed to enforce the cross-resource group resource dependency between SAP xserver and SAP liveCache.

Top

Probing Algorithm and Functionality

Sun Cluster HA for SAP liveCache has a fault monitor for each resource type.

• SAP xserver Fault Monitor (SUNW.sap_xserver)
• SAP liveCache Fault Monitor (SUNW.sap_livecache)

Top

SAP xserver Fault Monitor

The SAP xserver parent process is under the control of process monitor pmfadm. If the parent process is stopped or killed, the process monitor contacts the SAP xserver Fault Monitor, and the SAP xserver Fault Monitor decides what action must be taken.

The SAP xserver Fault Monitor performs the following steps in a loop.

1. Sleeps for Thorough_probe_interval.
2. Uses the SAP utility dbmcli with db_enum to check SAP xserver availability.
   • If SAP xserver is unavailable, SAP xserver probe restarts or fails over the SAP xserver resource if it reaches the maximum number of restarts.
   • If any system error messages are logged in syslog during the checking process, the SAP xserver probe concludes that a partial failure has occurred. If the system error messages logged in syslog occur four times within the probe_interval, SAP xserver probe restarts SAP xserver.

Top

SAP liveCache Fault Monitor

The SAP liveCache probe checks for the presence of the SAP liveCache parent process, the state of the SAP liveCache database, and whether the user intentionally stopped SAP liveCache outside of Sun Cluster software. If a user used the Stop liveCache button in LC10 or the lcinit command to stop SAP liveCache outside of Sun Cluster software, the SAP liveCache probe concludes that the user intentionally stopped SAP liveCache outside of Sun Cluster software.

If the user intentionally stopped SAP liveCache outside of Sun Cluster software by using the Stop liveCache button in LC10 or the lcinit command, the Sun Cluster HA for SAP liveCache Fault Monitor updates the resource state and status message to reflect this action, but it does not restart SAP liveCache. When the user successfully restarts SAP liveCache outside of Sun Cluster software by using the Start liveCache button in LC10 or the lcinit command, the Sun Cluster HA for SAP liveCache Fault Monitor updates the resource state and status message to indicate that SAP liveCache is running under the control of Sun Cluster software, and Sun Cluster HA for SAP liveCache Fault Monitor takes appropriate action if it detects SAP liveCache is OFFLINE.

If SAP liveCache database state reports that SAP liveCache is not running or that the SAP liveCache parent process terminated, the Sun Cluster HA for SAP liveCache Fault Monitor restarts or fails over SAP liveCache.

The Sun Cluster HA for SAP liveCache Fault Monitor performs the following steps in a loop. If any step returns SAP liveCache is offline, the SAP liveCache probe restarts or fails over SAP liveCache.

1. Sleeps for Thorough_probe_interval.
2. Uses the dbmcli utility with db_state to check the SAP liveCache database state.
3. If SAP liveCache is online, SAP liveCache probe checks the SAP liveCache parent process.
   • If the parent process terminates, SAP liveCache probe returns liveCache is offline.
   • If the parent process is online, SAP liveCache probe returns OK.
4. If SAP liveCache is not online, SAP liveCache probe determines if the user stopped SAP liveCache outside of Sun Cluster software by using the Stop liveCache button in LC10 or the lcinit command.
5. If the user stopped SAP liveCache outside of Sun Cluster software by using the Stop liveCache button in LC10 or the lcinit command, returns OK.
6. If the user did not stop SAP liveCache outside of Sun Cluster software by using the Stop liveCache button in LC10 or the lcinit command, checks SAP xserver availability.
   • If SAP xserver is unavailable, returns OK because the probe cannot restart SAP liveCache if SAP xserver is unavailable.
   • If SAP xserver is available, returns liveCache is offline.
7. If any errors are reported from system function calls, returns system failure.