What are Oracle RAC components?

What are services in Oracle RAC?

In Oracle RAC , Services are having much more features than just separating workload and administer it. A service is a logical grouping of sessions performing similar kind of work.Services enable you to group database workloads and route work to the optimal instances that are assigned to offer the service.

What are the four main daemons in RAC?

This includes start, stop, monitor, and failover operations. The crsd process generates events when the status of a resource changes.

What is Oracle RAC architecture?

The Oracle RAC option with Oracle Database enables you to cluster Oracle databases. Oracle RAC uses Oracle Clusterware for the infrastructure to bind multiple servers so they operate as a single system. Oracle Clusterware is a portable cluster management solution that is integrated with Oracle Database.

What is Clusterware components in Oracle RAC?

The Oracle Clusterware includes two important components: the voting disk and the Oracle Cluster Registry (OCR). The voting disk is a file that manages information about node membership and the OCR is a file that manages cluster and Oracle Real Application Clusters (Oracle RAC) database configuration information.

Oracle RAC Components | Basic cluster components

What is CSSD and Crsd in Oracle RAC?

Oracle Cluster Synchronization Services daemon (CSSD) Cluster Ready Services daemon (CRSD), which is the main engine for maintaining availability of resources. Event Manager daemon (EVMD)

What is OCR in Oracle 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.

What is a cluster in Oracle RAC?

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 RAC vs grid?

Thus, RAC is an integral part of Grid computing, but it is not the sum total of it. The goal of Grid computing is to supply high availability information sharing supported by an architecture with sufficient resource allocation such that users can rely on getting as much information or processing as they need on demand.

What processes are required in RAC?

How does Oracle RAC work?

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.

How does Oracle RAC startup sequence?

1) INIT : INIT is the very first file to be checked to be start at the time of the operating system boot,it is system and service manager for the Linux , Aix or any other Linux flavor. This service start and stop through script which is stored in the /etc/init. d directory .

What is Gipcd in Oracle RAC?

Grid Interprocess Communication (GIPC): A support daemon that enables Redundant Interconnect Usage.

How many nodes can Oracle RAC?

Oracle RAC 11g supports up to 100 nodes.

What is a node in Oracle RAC?

Oracle Real Application Clusters (RAC) One Node is an option to the Oracle Database Enterprise. Edition that was introduced with Oracle Database 11g Release 2. It provides enhanced high availability. for single instance Oracle Databases, protecting them from both, planned and unplanned downtime.

What is load balancing in Oracle RAC?

Load Balancing is a feature used in RAC Environment to share the Workload between the all the nodes present in RAC Environment to obtain maximum performance/throughput.

What is difference between standalone and RAC database?

In a single-instance database, there is a one-to-one relationship between the instance and the database. An instance can access one and only one database. With Oracle RAC, there are multiple instances for one database. Each instance runs on a separate database server, called a node in the cluster.

What is RAC in networking?

RAC stands for Real Application Clusters. It's a high availability solution for Oracle DB. Here two or more nodes (instances) are clustered as a single DB by using shared disks.

What is Oracle standalone cluster?

An Oracle Standalone Cluster hosts all Oracle Grid Infrastructure services and Oracle ASM locally and requires direct access to shared storage. Oracle Standalone Clusters contain two types of nodes arranged in a hub and spoke architecture: Hub Nodes and Leaf Nodes.

Is Oracle RAC active active?

Oracle RAC uses an active-active architecture that enables multiple database instances, each running on different nodes, to simultaneously read and write to the same database.

What are partitions in Oracle?

With Oracle Partitioning, a single logical object in the database is subdivided into multiple smaller physical objects, so-called partitions. The knowledge about this physical partitioning enables the database to improve the performance, manageability, or availability for any application.

What is the difference between database and instance?

Database Versus Instance

The database is the data on disk, stored in operating system files (or possibly, under Unix, in raw files). The instance is composed of the System Global Area (SGA) memory and the background processes. The instance is STARTed using Oracle Server Manager or Oracle Enterprise Manager (OEM).

What is scan IP and VIP in Oracle RAC?

SCAN virtual IP addresses (VIPs) function like node VIPs. However, unlike node VIPs, SCAN VIPs can run on any node in the cluster. Clients (users or applications) that connect using a SCAN instead of a node VIP name or address do not have to update the list of node names or addresses in their local tnsnames.

What is voting disk and OCR in Oracle RAC?

The voting disk is a file that manages information about node membership, and the OCR is a file that manages cluster and Oracle RAC database configuration information. The Oracle Clusterware installation process creates the voting disk and the OCR on shared storage.

What is node eviction in Oracle RAC?

A node eviction is done when a heartbeat indicates that a node is not responding, and the evicted node is re-started so that it can continue to partiipate in the cluster. Reason for RAC node evictions. There are many reasons for a RAC node eviction.