What are the components of RAC?

At a very high level, RAC architecture consists of these components:

Physical Nodes or Hosts.
Physical Interconnects and interconnect protocols.
Cluster Manager Software and Cluster Ready Services.
Oracle Instances and Cache Fusion.
Shared Disk System.
Clustered File System, Raw Devices, Automatic Storage Management.

What is RAC infrastructure?

Oracle Real Application Clusters (RAC) allow customers to run a single Oracle Database across multiple servers in order to maximize availability and enable horizontal scalability, while accessing shared storage.

What is Oracle Clusterware stack?

The Cluster Ready Services Stack The CRS daemon (crsd ) manages cluster resources based on the configuration information that is stored in OCR for each resource. This includes start, stop, monitor, and failover operations. Oracle ASM: Provides disk management for Oracle Clusterware and Oracle Database.

How many nodes are in RAC cluster?

Oracle RAC 11g supports up to 100 nodes.

What are Clusterware processes and daemons?

CSS has three separate processes: the CSS daemon (ocssd), the CSS Agent (cssdagent), and the CSS Monitor (cssdmonitor). The cssdagent process monitors the cluster and provides input/output fencing. This service formerly was provided by Oracle Process Monitor daemon (oprocd), also known as OraFenceService on Windows.

What is OCR in RAC?

Oracle Cluster Registry (OCR) The OCR contains cluster and database configuration information for RAC and Cluster Ready Services (CRS) such as the cluster node list, and cluster database instances to node mapping, and CRS application resource profiles. The OCR is a shared file located in a cluster file system.

How many nodes we can configure in RAC?

“Well, 3 nodes can be better than two if your workload is fully scalable, and there is no resource contention among the three nodes. I would venture to say that the majority of RAC systems are 2 node clusters, and are set up that way as part of a HA system instead of a workload scaling system.”

What is Nodeapps in RAC?

Nodeapps are a standard set of Oracle application services that are automatically launched for RAC (Real Application Cluster). The following service are lunched by nodeapps: •Virtual IP (VIP) •Oracle Net Listener. •Global Services Daemon (GSD)

How does Clusterware work in Oracle RAC architecture?

The Clusterware software allows nodes to communicate with each other and forms the cluster that makes the nodes work as a single logical server.

What do you need to know about Oracle RAC?

AUTOMATIC STORAGE MANAGEMENT (ASM): Oracle choice of storage management, its a portable, dedicated, and optimized cluster filesystem Oracle Clusterware software is designed to run Oracle in a cluster mode, it can support you to 64 nodes, it can even be used with a vendor cluster like Sun Cluster.

Where does Oracle Cluster Ready Services ( CRS ) reside?

The Oracle Cluster Ready Services (CRS) uses the registry to keep the cluster configuration, it should reside on shared storage and access to all nodes within the cluster.

Which is a mandatory component in 10g RAC?

The cluster-ready services (CRS) is a new component in 10g RAC, it is installed in a separate home directory called ORACLE_CRS_HOME. It is a mandatory component but can be used with a third party cluster (Veritas, Sun Cluster), by default it manages the node membership functionality along with managing regular RAC-related resources and services

What are the components of RAC? At a very high level, RAC architecture consists of these components: Physical Nodes or Hosts. Physical Interconnects and interconnect protocols. Cluster Manager Software and Cluster Ready Services. Oracle Instances and Cache Fusion. Shared Disk System. Clustered File System, Raw Devices, Automatic Storage Management. What is RAC infrastructure? Oracle Real…