Understanding Cluster Configuration Options

Review these topics to understand the cluster configuration options available in Oracle Grid Infrastructure.

Note:

Domain Services Clusters (DSC), which is part of the Oracle Cluster Domain architecture, are desupported.

Oracle Cluster Domains consist of a Domain Services Cluster (DSC) and Member Clusters. Member Clusters were deprecated in Oracle Grid Infrastructure 19c. The DSC continues to be available to provide services to production clusters. However, with most of those services no longer requiring the DSC for hosting, installation of DSCs are desupported in Oracle AI Database 26ai. Oracle recommends that you use any cluster or system of your choice for services previously hosted on the DSC, if applicable. Oracle will continue to support the DSC for hosting shared services, until each service can be used on alternative systems.

About Oracle Grid Infrastructure to Manage Oracle RAC Databases

An Oracle Grid Infrastructure deployment to manage Oracle RAC databases hosts all Oracle Grid Infrastructure services and Oracle ASM locally and requires direct access to shared storage.

Oracle Grid Infrastructure deployment to manage Oracle RAC databases contain multiple cluster nodes. The number of nodes in a cluster can be as many as 64. The cluster nodes can host different types of applications. Oracle Grid Infrastructure nodes are tightly connected, and have direct access to shared storage. Shared storage is locally mounted on each of the cluster nodes, with an Oracle ASM instance or a shared file system location available to all the nodes.

Note:

Starting with Oracle AI Database 26ai, Oracle Quality of Service Management (QoSM, or QoS Management) is desupported.

When you deploy Oracle Grid Infrastructure to manage Oracle RAC databases, you can also choose to configure it as an Oracle Extended cluster. An Oracle Extended Cluster consists of nodes that are located in multiple locations or sites.

About Oracle Grid Infrastructure to Manage Generic Applications

An Oracle Grid Infrastructure deployment to manage generic applications can host any applications for which you want to enable single-server rolling database maintenance, failover, and high availability.

Oracle Grid Infrastructure deployment to manage generic applications enables you to make your applications highly available without requiring Virtual IP addresses and shared storage. This deployment model can also extend high availability and single server rolling patching capabilities to single-instance Oracle AI Database.

You can configure Oracle Grid Infrastructure to manage generic applications without SCAN, GNS, VIPs, and without using separate network interfaces for Oracle ASM, private, and public communication. Such clusters can manage single-instance Oracle AI Database, any generic applications, or third-party databases using only one network interface.

Note:

You can easily convert this deployment model to an Oracle Grid Infrastructure cluster to manage Oracle RAC databases by adding shared storage and VIP.

About Oracle Extended Clusters

An Oracle Extended Cluster consists of nodes that are located in multiple locations called sites.

When you deploy an Oracle cluster, you can also choose to configure the cluster as an Oracle Extended Cluster. You can extend an Oracle cluster across two, or more, geographically separate sites, each equipped with its own storage. In the event that one of the sites fails, the other site acts as an active standby.

Both Oracle ASM and the Oracle AI Database stack, in general, are designed to use enterprise-class shared storage in a data center. Fibre Channel technology, however, enables you to distribute compute and storage resources across two or more data centers, and connect them through Ethernet cables and Fibre Channel, for compute and storage needs, respectively.

You can configure an Oracle Extended Cluster when you install Oracle Grid Infrastructure. You can also do so post installation using the ConvertToExtended script. You manage your Oracle Extended Cluster using CRSCTL.

You can assign nodes and failure groups to sites. Sites contain failure groups, and failure groups contain disks.

The following conditions apply when you select redundancy levels for Oracle Extended Clusters:

Table: Oracle ASM Disk Group Redundancy Levels for Oracle Extended Clusters with 2 Data Sites

Redundancy Level	Number of Failure Groups for OCR and Voting Files Disk Groups	Number of Failure Groups for OCR Backup
Normal redundancy	1 failure group per data site, 1 quorum failure group	1 failure group per data site
Flex redundancy	1 failure group per data site, 1 quorum failure group	1 failure group per data site, 1 quorum failure group
Extended redundancy	3 failure groups each for 2 data sites, 1 quorum failure group outside the 2 data sites	3 failure groups each for 2 data sites, 1 quorum failure group outside the 2 data sites
High redundancy	Not supported	Not supported