Sun Cluster Concepts Guide for Solaris OS

Resources, Resource Groups, and Resource Types

Data services use several types of resources: applications such as Sun Java System Web Server or Apache Web Server use network addresses (logical host names and shared addresses) on which the applications depend. Application and network resources form a basic unit that is managed by the RGM.

Data services are resource types. For example, Sun Cluster HA for Oracle is the resource type and Sun Cluster HA for Apache is the resource type SUNW.apache.

A resource is an instantiation of a resource type that is defined cluster wide. Several resource types are defined.

Network resources are either SUNW.LogicalHostname or SUNW.SharedAddress resource types. These two resource types are preregistered by the Sun Cluster software.

The HAStoragePlus resource type is used to synchronize the startup of resources and device groups on which the resources depend. This resource type ensures that before a data service starts, the paths to a cluster file system's mount points, global devices, and device group names are available. For more information, see Synchronizing the Startups Between Resource Groups and Device Groups in Sun Cluster Data Services Planning and Administration Guide for Solaris OS. The HAStoragePlus resource type also enables local file systems to be highly available. For more information about this feature, see HAStoragePlus Resource Type.

RGM-managed resources are placed into groups, called resource groups, so that they can be managed as a unit. A resource group is migrated as a unit if a failover or switchover is initiated on the resource group.

Note –

When you bring a resource group that contains application resources online, the application is started. The data service start method waits until the application is running before exiting successfully. The determination of when the application is up and running is accomplished the same way the data service fault monitor determines that a data service is serving clients. Refer to the Sun Cluster Data Services Planning and Administration Guide for Solaris OS for more information about this process.

Resource Group Manager (RGM)

The RGM controls data services (applications) as resources, which are managed by resource type implementations. These implementations are either supplied by Sun or created by a developer with a generic data service template, the Data Service Development Library API (DSDL API), or the Resource Management API (RMAPI). The cluster administrator creates and manages resources in containers called resource groups. The RGM stops and starts resource groups on selected nodes in response to cluster membership changes.

The RGM acts on resources and resource groups. RGM actions cause resources and resource groups to move between online and offline states. A complete description of the states and settings that can be applied to resources and resource groups is located in Resource and Resource Group States and Settings.

Refer to Data Service Project Configuration for information about how to launch Solaris projects under RGM control.

Resource and Resource Group States and Settings

A system administrator applies static settings to resources and resource groups. You can change these settings only by administrative action. The RGM moves resource groups between dynamic “states.”

These settings and states are as follows:

Resource and Resource Group Properties

You can configure property values for resources and resource groups for your Sun Cluster data services. Standard properties are common to all data services. Extension properties are specific to each data service. Some standard and extension properties are configured with default settings so that you do not have to modify them. Others need to be set as part of the process of creating and configuring resources. The documentation for each data service specifies which resource properties can be set and how to set them.

The standard properties are used to configure resource and resource group properties that are usually independent of any particular data service. For the set of standard properties, see Appendix B, Standard Properties, in Sun Cluster Data Services Planning and Administration Guide for Solaris OS.

The RGM extension properties provide information such as the location of application binaries and configuration files. You modify extension properties as you configure your data services. The set of extension properties is described in the individual guide for the data service.