Clusters are interconnected servers or computers that look like they are just one server or computer to applications and end users. In using Oracle Real Application Clusters (RAC), you can cluster your databases. These may look and work like a single database, but there are some things that are different. For one, single instance databases have a 1:1 relationship between the instance and the database itself. In Oracle Real Application Clusters, it can involve 100 instances accessing only one database.
Here is what you should know about Oracle Real Application Clusters’ architecture.
Oracle Real Application Clusters works on a shared-everything principle, which means that all the control files, data files, SPFILEs and redo logs are located in cluster-aware shared disks that are accessible to all cluster database instances. This means that database files for Oracle Real Application Clusters need to be stored in a cluster-aware storage. You can choose how you are going to configure your disk, but the storage should be cluster-aware. This means that you are limited to using:
- Automatic Storage Management
- Oracle Cluster File System
- A network file system
- Raw devices
What’s more, all nodes in the Oracle Real Application Clusters environment should be connected to a LAN so that applications and users can access that database using the Oracle Database services feature.
The Oracle Database services feature allows you to institute rules and control over how users connect to the database.
You can use a client/server configuration to allow users to access your Oracle Real Application Clusters database. These are reserved for power users who create their own searches, such as the database administrators, data miners, application users and other power users. Public networks, however, use TCP/IP or any supported software and hardware. You can access Oracle Real Application Clusters instances via the database’s default IP address or any VIP addresses.
You should also assign virtual host names and IP addresses to all your nodes. Here, virtual host names and IP addresses would be used to connect to your database instance.
The Oracle Real Application Clusters Components
The Oracle Real Application Clusters database has two or more instances that have background processes and memory structures. It will have the same memory structures and processes as a single instance database, plus those that are unique to Oracle Real Application Clusters.
If you are struggling working with Oracle Application Clusters, or if you simply want to learn more about it, call Four Cornerstone today. We have a team of certified Oracle experts who could easily teach you more about Oracle Application Clusters, its architecture, how it is designed, and, more importantly, how to deploy it. We can help you with everything that is related to Oracle and MySQL. Four Cornerstone offers database performance tuning, data warehousing, disaster recovery, remote Oracle DBA support, database development, database environment assessment and extensive MySQL support. We can also assist you with your software licensing needs.
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Article Source: Oracle
Photo courtesy of Oracle.
