FAQ - Oracle Clusterware For Oracle Linux
A cluster is a group of independent servers used in a network that cooperate as a single system. Clustering is a technique used to create a highly available and easily scalable environment. Cluster software is the software running on each of these servers that provides the intelligence, which enables the coordinated cooperation of those servers. If one of the cluster servers fails, the work previously running on that server can be restarted on another available server in the cluster.
Oracle Clusterware is a portable cluster software that allows clustering of single servers so that they cooperate as a single system. Oracle Clusterware also provides the required infrastructure for Oracle Real Application Clusters (RAC). In addition Oracle Clusterware enables the protection of any Oracle application or any other kind of application within a cluster.
Oracle Linux Support customers at the Basic or Premier level are now entitled, at no additional license and support costs, to download and deploy Oracle Clusterware in a Linux cluster covered under their Oracle Linux Support agreement. This provides customers with the ability to enable applications running in the cluster to be monitored and managed by Oracle Clusterware for high availability.
Oracle is committed to making Linux more scalable, available and overall a better enterprise platform. Oracle Clusterware provides high availability for all applications. With the increased acceptance of the Linux operating system in enterprises and data centers of all sizes, there is also an increased demand for higher availability of the applications running on these Linux systems. Servers that might be running a web server such as Apache, or an application server such as Oracle Application Server, or applications such as Oracle E-Business Suite, Peoplesoft or Siebel need to be monitored and managed for high availability.
Oracle recommends using Oracle Clusterware as the underlying clustering solution for Linux systems whenever clustering is required to ensure high availability for applications of any kind. Customers who have a Basic or Premier Oracle Linux Support agreement with Oracle are entitled to use Oracle Clusterware at no additional charge. A single point of contact for the entire software infrastructure stack along with Oracle's top-to-bottom software compatibility, results in improved responsiveness, reduced system downtime and increased system reliability.
Oracle Clusterware provides high availability for any kind of application. Oracle Clusterware is based on proven cluster technology and has been ported to all the operating systems certified for Oracle Real Application clusters. Oracle Clusterware is the most common clustering solution for Linux today and was one of the first fully supported clustering solutions for Linux. This offers Oracle's customers a solid and proven clustering solution built with two decades of clustering experience.
How do I protect my application with Oracle Clusterware?
Oracle documentation describes how Oracle Clusterware can be used in various environments and additional examples of how to protect typical applications can be found here: http://otn.oracle.com/clusterware
In the event of a system failure, clustering ensures high availability to users. Redundant hardware components, such as additional nodes, interconnect, and disks, allow the cluster to provide high availability. Such redundant hardware architectures avoid single points-of-failure and provide exceptional fault resilience.
In Oracle Real Application Clusters (RAC) environments, Oracle Clusterware monitors and manages Real Application Cluster databases. When a node in the cluster is started, all instances, listeners and services are automatically started. If an instance fails, the clusterware will automatically restart the instance, so that the service is often restored before the administrator notices it was down. In this sense Oracle Clusterware is the basis for Oracle Real Application Clusters.
In those environments RAC ensures the continuous operation of the database as well as its scalability by running more than one database instance simultaneously, typically one on every node in the cluster.
Oracle Clusterware and the Oracle Management Pack for Linux are two totally independent products. However, the Management Pack for Linux requires the Oracle Enterprise Manager infrastructure. Once this infrastructure is set up, one cannot only manage Oracle Linux environments including the ability to monitor and manage servers, but also Oracle Databases (Single Instance Databases as well as Oracle Real Application Clusters databases) and Oracle Application Servers.
Based on Oracle's two decades of experience in cluster software, Oracle Clusterware is one of the first fully supported clustering solutions available for Linux. Oracle's cluster solutions for Linux, based on Oracle Clusterware as well as the Oracle Cluster File System Version 2 (OCFS2), can be utilized together or separately as required.
Oracle Clusterware is supported on all Operating Systems certified for Oracle Real Application Clusters. For more information about supported Operating Systems and configurations for Oracle Real Application Clusters consult: www.oracle.com/technology/support/metalink/index.html
There are no specific hardware or software requirements for Oracle Clusterware. All certification and technology requirements for Oracle Real Application Clusters apply to Oracle Clusterware. Current detailed information on certifications and technology requirements related to Oracle Real Application Clusters can be obtained through Oracle Metalink / Certify. The current minimum hardware requirements specific to Oracle Clusterware on Linux can be found here: www.oracle.com/technology/products/database/clustering/certify/tech_generic_linux_new.html The general software requirements can be found in the official Oracle documentation.
In addition to the official Oracle documentation, Oracle maintains Oracle Metalink Note 220970.1 - "RAC Frequently Asked Questions" in order to address the most common questions regarding Oracle Clusterware and Oracle Real Application Clusters. Access to Oracle Metalink requires a valid Oracle Customer Support Identifier (CSI), usually received with the purchase of an Oracle Support Contract. For Service Requests regarding Oracle Clusterware, contact Oracle Support through Oracle Metalink. For sharing general information as well as your experience, go to forums.oracle.com
Oracle Linux Support customers at the Basic and Premier levels can download the product and deploy it for free as part of their Oracle Linux Support contract.