Configuration Planning Questions

Use the questions in the subsections that follow to plan the installation and configuration of Sun Cluster Support for Oracle Real Application Clusters. Write the answers to these questions in the space that is provided on the data service worksheets in Configuration Worksheets in Sun Cluster Data Services Planning and Administration Guide for Solaris OS.

Resource Groups for Oracle RAC Server Resources

If you are using Oracle 10g, no Oracle RAC server resources are required. These resources are not required with Oracle 10g because Oracle CRS starts and shuts down Oracle Real Application Clusters database instances. In versions of Oracle earlier than 10g, these resources are required to enable Sun Cluster to start and shut down database instances.

Which resource groups will you use for the Oracle Real Application Clusters (RAC) server resources?

You require one resource group for each Oracle Real Application Clusters database instance. Each resource group contains the Oracle RAC server resource for the database instance.

Use the answer to this question when you perform the procedure in Registering and Configuring Oracle RAC Server Resources.

Resource Groups for Oracle Listener Resources

If you are using Oracle 10g, no Oracle listener resources are required. These resources are not required with Oracle 10g because Oracle CRS starts and shuts down Oracle Real Application Clusters database instances. In versions of Oracle earlier than 10g, these resources are required to enable Sun Cluster to start and shut down database instances.

Which resource groups will you use for the Oracle listener resources?

Use the answer to this question when you perform the procedure in Registering and Configuring Oracle Listener Resources.

The resource groups depend on your configuration of Oracle listeners with Real Application Clusters database instances. For general information about possible configurations of listeners for Real Application Clusters instances, see your Oracle documentation. Example configurations are described in the subsections that follow.

One Listener for One Real Application Clusters Instance

One listener serves only one Real Application Clusters instance. The listener listens on the fixed Internet Protocol (IP) address of the node. The listener cannot fail over.

In this situation, configure the listener resource as follows:

• Configure the listener resource and the RAC server resource in the same resource group.

• Ensure that this resource group is mastered on only one node.

One Listener That Cannot Fail Over for Several Real Application Clusters Instances

One listener serves several Real Application Clusters instances on the same node. The listener uses Oracle's transparent application failover (TAF) and load balancing to distribute client connections across all Real Application Clusters instances. The listener cannot fail over.

In this situation, configure the listener resource as follows:

• Configure the listener resource in its own resource group.

• Ensure that the listener's resource group is mastered on only one node.

• Create a dependency between the listener's resource group and RAC servers' resource groups.

One Listener That Can Fail Over for Several Real Application Clusters Instances

One listener that can fail over serves several Real Application Clusters instances on the same node. When the listener fails over to another node, the listener serves several Real Application Clusters instances on the other node.

The listener uses Oracle's TAF and load balancing to distribute client connections across all Real Application Clusters instances. To ensure fast error detection and short failover times, the listener listens on an address that is represented by a LogicalHostname resource.

In this situation, configure the listener resource as follows:

• Configure the listener resource and the LogicalHostname resource in the same resource group.

• Ensure that this resource group is mastered on the nodes on which Oracle Real Application Clusters is running.

For more information, see LogicalHostname Resources for Oracle Listener Resources.

One Listener for the Entire Cluster

One listener serves all Real Application Clusters instances on all nodes. The listener listens on an address that is represented by a LogicalHostname resource. This configuration ensures that the address is plumbed very quickly on another node after a node fails.

You can use this configuration if you configure Real Application Clusters instances to use a multithreaded server (MTS). In such a configuration, the REMOTE_LISTENERS parameter in the init.ora file specifies that each dispatcher registers with the listener on a logical IP address.

All clients connect through the one listener. The listener redirects each client connection to the least busy dispatcher. The least busy dispatcher might be on a different node from the listener.

If the listener fails, the listener's fault monitor restarts the listener. If the node where the listener is running fails, the listener is restarted on a different node. In both situations the dispatchers reregister after the listener is restarted.

If you are using one listener for the entire cluster, configure the following resources in the same resource group:

• The listener resource

• The LogicalHostname resource

For more information, see LogicalHostname Resources for Oracle Listener Resources.

LogicalHostname Resources for Oracle Listener Resources

If you are using Oracle 10g, no LogicalHostname resources are required.

Which LogicalHostname resources will Oracle listener resources use?

Use the answer to this question when you perform the procedure in Registering and Configuring Oracle Listener Resources.

If a cluster node that is running an instance of Oracle Real Application Clusters fails, an operation that a client application attempted might be required to time out before the operation is attempted again on another instance. If the Transmission Control Protocol/Internet Protocol (TCP/IP) network timeout is high, the client application might require a significant length of time to detect the failure. Typically, client applications require between three and nine minutes to detect such failures.

In such situations, client applications can connect to listener resources that are listening on an address that is represented by the Sun Cluster LogicalHostname resource. Configure the LogicalHostname resource and the listener resource in a separate resource group. Ensure that this resource group is mastered on the nodes on which Oracle Real Application Clusters is running. If a node fails, the resource group that contains the LogicalHostname resource and the listener resource fails over to another surviving node on which Oracle Real Application Clusters is running. The failover of the LogicalHostname resource enables new connections to be directed to the other instance of Oracle Real Application Clusters.

SPARC: Resources for the Sun StorEdge QFS Shared File System

If you are using the Sun StorEdge QFS shared file system, answer the following questions:

• Which resources will you create to represent the metadata server for the Sun StorEdge QFS shared file system?

  One resource is required for each Sun StorEdge QFS metadata server.

• Which resource groups will you use for these resources?

  You might use multiple file systems for database files and related files. For more information, see SPARC: Requirements for Using the Sun StorEdge QFS Shared File System.

  If you are using Oracle 10g, Oracle CRS manage Real Application Clusters database instances. These database instances must be started only after all shared file systems are mounted. To meet this requirement, ensure that the file system that contains the Oracle CRS voting disk is mounted only after the file systems for other database files have been mounted. This behavior ensures that, when a node is booted, Oracle CRS are started only after all Sun StorEdge QFS file systems are mounted.

  To enable Sun Cluster to mount the file systems in the required order, configure resource groups for the metadata servers of the file systems as follows:

  • Create the resources for the metadata servers in separate resource groups.

  • Set the resource group for the file system that contains the Oracle CRS voting disk to depend on the other resource groups.

For more information, see the following documentation for Sun StorEdge QFS:

• Sun StorEdge QFS and Sun StorEdge SAM-FS Software Installation and Configuration Guide

• Sun StorEdge QFS and Sun StorEdge SAM-FS File System Administration Guide

Use the answers to these questions when you perform the procedure in Registering and Configuring Oracle RAC Server Resources.

Name of the RAC Framework Resource Group

If you plan you use the scrgadm utility to create the RAC framework resource group, what name will you assign to this resource group?

If you use the scsetup utility to create the RAC framework resource group, omit this question. The scsetup utility automatically assigns a name when you create the resource group.

For more information, see Registering and Configuring the RAC Framework Resource Group.

Location of Oracle Configuration Files

Where will the Oracle configuration files reside?

For the advantages and disadvantages of using the local file system instead of the cluster file system, see Storage Management Requirements for Oracle Binary Files and Oracle Configuration Files.