Oracle Real Application Clusters (RAC) are interconnected Oracle Databases that appear as one database to applications and users. Unlike single instance databases, however, Oracle Application Clusters databases can handle many instances on a single server.
Oracle Clusterware is the cluster management software that comes with Oracle Database to help you use Oracle Real Application Clusters, as well as single-instance databases. You could use it with any platform that you are using.
What is Oracle Clusterware?
Oracle Clusterware gives you a comprehensive and complete clusterware management tool that comes together with Oracle Database.
In short, Clusterware allows you to operate several servers together and act as if they are one server to applications and users. This allows you to easily scale for applications, use more affordable hardware, get fail-over abilities and just add capacity over a period of time simply by adding servers when you need to.
What this means is that you can use it to help you manage all the things and processes you need to manage as far as Oracle Real Application Clusters is concerned. That includes group services, node membership, high availability features and global resource management.
Not just for Oracle Real Application Clusters
And even if you are not using Oracle Real Application Clusters, there are still some Oracle Database functionalities that would need Oracle Clusterware. For instance, the Services feature needs Oracle Clusterware to run.
Oracle Clusterware was made for Oracle Real Application Clusters. You cannot have an Oracle Real Application Clusters database without Oracle Clusterware. You would need Clusterware to register and manage your databases. You would also need to use Oracle Clusterware for Virtual Internet Protocol addressing, Oracle Notification Service, Oracle Net listeners and Global Services Daemon, as well as other Oracle Database processes.
In an Oracle Real Application Clusters database, it is Oracle Clusterware that manages all the processes in that database.
Furthermore, you would be able to manage high-availability operations and instances in a cluster.
The CRS Resource
The cluster resource, or CRS Resource is a database, a service, a VIP address, an instance, a process, a listener, an application process or anything that Clusterware manages. These resources are managed according to the configuration information you have in the Oracle Cluster Registry. The Oracle Clusterware keeps the configuration information to see how to configure these components.
When you create a cluster using Oracle Clusterware, you will be able to:
- Get rid of unplanned downtimes due to malfunctions in your hardware or software.
- Minimize planned downtimes you need to maintain your software.
- Add servers as needed to increase throughput for an application.
- Lower the total cost of ownership by enabling you to use low-cost hardware when you scale your systems.
What’s more, applications can run on all the cluster nodes to help increase throughput.
Interested in knowing how to use Oracle Clusterware for your Oracle Database or Oracle Real Application Clusters? Call Four Cornerstone at 1 (817) 377-1144 and talk to us about how we can help you. We have a team of certified Oracle Clusterware experts who can help you understand the software and how to deploy it. We can also train your IT staff on Oracle Clusterware, Oracle Real Application Clusters and other Oracle software and products.
Article Source: Oracle
Photo courtesy of Oracle.