Data Services FAQ

• What Sun Cluster data services are available?

  The list of supported data services is included in the Sun Cluster 3.0 Release Notes.

• What application versions are supported by Sun Cluster data services?

  The list of supported application versions is included in the Sun Cluster 3.0 Release Notes.

• Can I write my own data service?

  Yes. See the Sun Cluster 3.0 Data Services Developers' Guide and the Data Service Enabling Technologies documentation provided with the Data Service Development Library API for more information.

• When creating network resources, should I specify numeric IP addresses or hostnames?

  The preferred method for specifying network resources is to use the UNIX hostname rather than the numeric IP address.

• When creating network resources, what is the difference between using a logical hostname (a LogicalHostname resource) or a shared address (a SharedAddress resource)?

  Wherever the documentation calls for the use of a LogicalHostname resource in a Failover mode resource group, a SharedAddress resource or LogicalHostname resource may be used interchangeably. The use of a SharedAddress resource incurs some additional overhead because the cluster networking software is configured for a SharedAddress but not for a LogicalHostname.

  The advantage to using a SharedAddress is the case where you are configuring both scalable and failover data services, and want clients to be able to access both services using the same hostname. In this case, the SharedAddress resource(s) along with the failover application resource are contained in one resource group, while the scalable service resource is contained in a separate resource group and configured to use the SharedAddress. Both the scalable and failover services may then use the same set of hostnames/addresses which are configured in the SharedAddress resource.