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Sun Cluster Data Services Planning and Administration Guide for Solaris OS

Chapter 1 Planning for Sun Cluster Data Services

This chapter provides planning information and guidelines to install and configure Sun Cluster data services. This chapter contains the following sections.

For information about data services, resource types, resources, and resource groups, see Sun Cluster Concepts Guide for Solaris OS.

Sun Cluster software can provide service only for those data services that are either supplied with the Sun Cluster product or are created with the Sun Cluster data services application programming interfaces (APIs).

If a Sun Cluster data service is not provided for your application, consider developing a custom data service for the application. To develop a custom data service, use the Sun Cluster data services APIs. For more information, see Sun Cluster Data Services Developer’s Guide for Solaris OS.

Note –

Sun Cluster does not provide a data service for the sendmail(1M) subsystem. The sendmail subsystem can run on the individual cluster nodes, but the sendmail functionality is not highly available. This restriction applies to all the sendmail functionality, including the functionality of mail delivery and mail routing, queuing, and retry.

Configuration Guidelines for Sun Cluster Data Services

This section provides configuration guidelines for Sun Cluster data services.

Identifying Data Service Special Requirements

Identify requirements for all of the data services before you begin Solaris and Sun Cluster installation. Failure to do so might result in installation errors that require that you completely reinstall the Solaris and Sun Cluster software.

For example, the Oracle Parallel Fail Safe/Real Application Clusters Guard option of Sun Cluster Support for Oracle Parallel Server/Real Application Clusters has special requirements for the hostnames that you use in the cluster. Sun Cluster HA for SAP also has special requirements. You must accommodate these requirements before you install Sun Cluster software because you cannot change hostnames after you install Sun Cluster software.

Note –

Some Sun Cluster data services are not supported for use in x86 based clusters. For more information, see the release notes for your release of Sun Cluster at http://docs.sun.com.

Determining the Location of the Application Binaries

You can install the application software and application configuration files on one of the following locations.

Verifying the nsswitch.conf File Contents

The nsswitch.conf file is the configuration file for name-service lookups. This file determines the following information.

Some data services require that you direct “group” lookups to “files” first. For these data services, change the “group” line in the nsswitch.conf file so that the “files” entry is listed first. See the documentation for the data service that you plan to configure to determine whether you need to change the “group” line.

For additional information about how to configure the nsswitch.conf file for the Sun Cluster environment, see Planning the Sun Cluster Environment in Sun Cluster Software Installation Guide for Solaris OS.

Planning the Cluster File System Configuration

Depending on the data service, you might need to configure the cluster file system to meet Sun Cluster requirements. To determine whether any special considerations apply, see the documentation for the data service that you plan to configure.

For information about how to create cluster file systems, see Planning the Global Devices and Cluster File Systems in Sun Cluster Software Installation Guide for Solaris OS.

The resource type HAStoragePlus enables you to use a highly available local file system in a Sun Cluster environment that is configured for failover. For information about setting up the HAStoragePlus resource type, see Enabling Highly Available Local File Systems.

Enabling Solaris SMF Services to Run Under the Control of Sun Cluster

You might require Sun Cluster to make highly available an application other than NFS or DNS that is integrated with the Solaris Service Management Facility (SMF). To ensure that Sun Cluster can restart or fail over the application correctly after a failure, you must disable SMF service instances for the application as follows:

Note –

If you do not disable the SMF service instances of the application, both the Solaris SMF and Sun Cluster might attempt to control the startup and shutdown of the application. As a result, the behavior of the application might become unpredictable.

For more information, see the following documentation:

Relationship Between Resource Groups and Disk Device Groups

Sun Cluster uses the concept of node lists for disk device groups and resource groups. Node lists are ordered lists of primary nodes, which are potential masters of the disk device group or resource group. Sun Cluster uses a failback policy to determine the behavior of Sun Cluster in response to the following set of conditions:

If failback is set to True, the device group or resource group is switched off the current primary and switched onto the rejoining node, making the rejoining node the new primary.

For example, assume that you have a disk device group, disk-group-1, that has nodes phys-schost-1 and phys-schost-2 in its node list, with the failback policy set to Enabled. Assume that you also have a failover resource group, resource-group-1, which uses disk-group-1 to hold its application data. When you set up resource-group-1, also specify phys-schost-1 and phys-schost-2 for the resource group's node list, and set the failback policy to True.

To ensure high availability of a scalable resource group, make the scalable resource group's node list a superset of the node list for the disk device group. Doing so ensures that the nodes that are directly connected to the disks are also nodes that can run the scalable resource group. The advantage is that, when at least one cluster node connected to the data is up, the scalable resource group runs on that same node, making the scalable services available also.

For more information about the relationship between disk device groups and resource groups, see Disk Device Groups in Sun Cluster Overview for Solaris OS.

For information about how to set up disk device groups, see the following documentation:

Understanding HAStorage and HAStoragePlus

The HAStorage and the HAStoragePlus resource types can be used to configure the following options.

In addition, HAStoragePlus is capable of mounting any global file system that is in an unmounted state. For more information, see Planning the Cluster File System Configuration.

Note –

If the device group is switched to another node while the HAStorage or HAStoragePlus resource is online, AffinityOn has no effect. The resource group does not migrate with the device group. However, if the resource group is switched to another node, the setting of AffinityOn to True causes the device group to follow the resource group to the new node.

See Synchronizing the Startups Between Resource Groups and Disk Device Groups for information about the relationship between disk device groups and resource groups. The SUNW.HAStorage(5) and SUNW.HAStoragePlus(5) man pages provide additional details.

See Enabling Highly Available Local File Systems for procedures for mounting of file systems such as VxFS in a local mode. The SUNW.HAStoragePlus(5) man page provides additional details.

Determining Whether Your Data Service Requires HAStorage or HAStoragePlus

The following types of data services require HAStorage or HAStoragePlus:

Data Services With Nodes That Are Not Directly Connected to Storage

Some nodes in the node list of a data service's resource group might not be directly connected to the storage. In this situation, you must coordinate the boot order between the storage and the data service. To meet this requirement, configure the resource group as follows:

Data Services That Are Disk Intensive

Some data services, such as Sun Cluster HA for Oracle and Sun Cluster HA for NFS are disk intensive. If your data service is disk intensive, ensure that the resource groups and disk device groups are colocated on the same node. To meet this requirement, perform the following tasks.

Note –

The failback settings must be identical for both the resource group and device groups.

Some data services are not disk intensive. For example, Sun Cluster HA for DNS, which reads all of its files at startup, is not disk intensive. If your data service is not disk intensive, configuring the HAStorage resource type or HAStoragePlus resource type is optional.

Choosing Between HAStorage and HAStoragePlus

To determine whether to create HAStorageresources or HAStoragePlus resources in a data service resource group, consider the following criteria.

Note –

To integrate any file system locally into a Sun Cluster environment that is configured for failover, you use the HAStoragePlus resource type. For more information, see Planning the Cluster File System Configuration. If you are using Sun Cluster 3.0 12/01 or earlier, you must first upgrade to Sun Cluster 3.0 5/02 or Sun Cluster 3.1.

Considerations for Installing and Configuring a Data Service

Use the information in this section to plan the installation and configuration of any data service. The information in this section encourages you to think about the impact your decisions have on the installation and configuration of any data service. For specific considerations for a data service, see the documentation for the data service.

Node List Properties

You can specify the following node list properties when configuring data services.

installed_nodes Property

The installed_nodes property is a property of the resource type for the data service. This property is a list of the cluster node names on which the resource type is installed and enabled to run.

nodelist Property

The nodelist property is a property of a resource group. This property specifies a list of cluster node names where the group can be brought online, in order of preference. These nodes are known as the potential primaries or masters of the resource group. For failover services, configure only one resource group node list. For scalable services, configure two resource groups and thus two node lists. One resource group and its node list identify the nodes on which the shared addresses are hosted. This list is a failover resource group on which the scalable resources depend. The other resource group and its list identify nodes on which the application resources are hosted. The application resources depend on the shared addresses. Therefore, the node list for the resource group that contains the shared addresses must be a superset of the node list for the application resources.

auxnodelist Property

The auxnodelist property is a property of a shared address resource. This property is a list of physical node IDs that identify cluster nodes that can host the shared address but never serve as primary in the case of failover. These nodes are mutually exclusive with the nodes that are identified in the node list of the resource group. This list pertains to scalable services only. For details, see the scrgadm(1M) man page.

Overview of the Installation and Configuration Process

Use the following procedures to install and configure a data service.

Before you install and configure data services, see Sun Cluster Software Installation Guide for Solaris OS, which includes instructions for the following tasks:

Note –

You can use SunPlexTM Manager to install and configure the following data services: Sun Cluster HA for Oracle, Sun Cluster HA for Sun JavaTM System Web Server, Sun Cluster HA for Sun Java System Directory Server, Sun Cluster HA for Apache, Sun Cluster HA for DNS, and Sun Cluster HA for NFS. See the SunPlex Manager online help for more information.

Installation and Configuration Task Flow

The following table summarizes the tasks for installing and configuring Sun Cluster data services. The table also provides cross-references to detailed instructions for performing the tasks.

Table 1–1 Tasks for Installing and Configuring Sun Cluster Data Services

Task 

Instructions 

Install the Solaris and Sun Cluster software 

Sun Cluster Software Installation Guide for Solaris OS

Set up IP Networking Multipathing groups 

Sun Cluster Software Installation Guide for Solaris OS

Set up multihost disks 

Sun Cluster Software Installation Guide for Solaris OS

Plan resources and resource groups 

Appendix C, Data Service Configuration Worksheets and Examples

Decide the location for application binaries, and configure the nsswitch.conf file

Determining the Location of the Application Binaries

Verifying the nsswitch.conf File Contents

Install and configure the application software 

The appropriate Sun Cluster data services book 

Install the data service software packages 

Sun Cluster Software Installation Guide for Solaris OS or the appropriate Sun Cluster data services book

Register and configure the data service 

The appropriate Sun Cluster data services book 

Example of Configuring a Failover Data Service

This example summarizes how to set up the resource types, resources, and resource groups that a failover data service for the Oracle application requires. For complete instructions for configuring the data service for the Oracle application, see Sun Cluster Data Service for Oracle Guide for Solaris OS.

The principal difference between this example and an example of a scalable data service is as follows: In addition to the failover resource group that contains the network resources, a scalable data service requires a separate resource group (scalable resource group) for the application resources.

The Oracle application has two components, a server and a listener. Sun supplies the Sun Cluster HA for Oracle data service, and therefore these components have already been mapped into Sun Cluster resource types. Both of these resource types are associated with resources and resource groups.

Because this example is a failover data service, the example uses logical hostname network resources, which are the IP addresses that fail over from a primary node to a secondary node. Place the logical hostname resources into a failover resource group, and then place the Oracle server resources and listener resources into the same resource group. This ordering enables all of the resources to fail over as a group.

For Sun Cluster HA for Oracle to run on the cluster, you must define the following objects.

Tools for Data Service Resource Administration

This section describes the tools that you can use to perform installation and configuration tasks.

The SunPlex Manager Graphical User Interface (GUI)

SunPlex Manager is a web-based tool that enables you to perform the following tasks.

For instructions for using use SunPlex Manager to install cluster software, see Sun Cluster Software Installation Guide for Solaris OS. SunPlex Manager provides online help for most administrative tasks.

SPARC: The Sun Cluster Module for the Sun Management Center GUI

The Sun Cluster module enables you to monitor clusters and to perform some operations on resources and resource groups from the Sun Management Center GUI. See the Sun Cluster Software Installation Guide for Solaris OS for information about installation requirements and procedures for the Sun Cluster module. Go to http://docs.sun.com to access the Sun Management Center software documentation set, which provides additional information about Sun Management Center.

The scsetup Utility

The scsetup(1M) utility is a menu-driven interface that you can use for general Sun Cluster administration. You can also use this utility to configure data service resources and resource groups. Select option 2 from the scsetup main menu to launch the Resource Group Manager submenu.

The scrgadm Command

You can use the scrgadm command to register and configure data service resources. See the procedure for how to register and configure your data service in the book for the data service. If, for example, you are using Sun Cluster HA for Oracle, see Registering and Configuring Sun Cluster HA for Oracle in Sun Cluster Data Service for Oracle Guide for Solaris OS.

For more information about how to use the scrgadm command to administer data service resources, see the following documentation:

Summary by Task of Tools for Administering Data Service Resources

The following table summarizes by task which tool you can use in addition to the command line for administering data service resources. For more information about these tasks and for details about how to use the command line to complete related procedures, see Chapter 2, Administering Data Service Resources.

Table 1–2 Tools for Administering Data Service Resources

Task 

SunPlex Manager 

SPARC: Sun Management Center 

scsetup Utility

Register a resource type 

Yes 

No 

Yes 

Create a resource group 

Yes 

No 

Yes 

Add a resource to a resource group 

Yes 

No 

Yes 

Bring a resource group online 

Yes 

Yes 

No 

Remove a resource group 

Yes 

Yes 

No 

Remove a resource 

Yes 

Yes 

No 

Switch the current primary of a resource group 

Yes 

No 

No 

Disable a resource 

Yes 

Yes 

No 

Move the resource group of a disabled resource into the unmanaged state 

Yes 

No 

No 

Display resource type, resource group, and resource configuration information 

Yes 

Yes 

No 

Change resource properties 

Yes 

No 

No 

Clear the STOP_FAILED error flag on resources

Yes 

No 

No 

Add a node to a resource group 

Yes 

No 

No