**Pacemaker** is a high-availability cluster resource manager. It achieves maximum availability for your cluster services (//resources//) by detecting and recovering from node- and resource-level failures by making use of the messaging and membership capabilities provided by Corosync. It can do this for clusters of practically any size and comes with a powerful dependency model that allows the administrator to accurately express the relationships (both ordering and location) between the cluster resources. Virtually anything that can be scripted can be managed as part of a Pacemaker cluster. == Project Information == * [[License]] * [[https://clusterlabs.org/#features|Features]] * [[https://clusterlabs.org/quickstart.html|Get Pacemaker]] * [[https://clusterlabs.org/doc/|Documentation]] * [[https://clusterlabs.org/help.html|Support]] == Availability == {{:Availability}} == Example Configurations == {{:ClusterTypes}} == Architecture == See the "Cluster Architecture" section of Pacemaker Explained from the [[https://clusterlabs.org/pacemaker/doc/|Pacemaker documentation set]]. == Project History == {{:Project History}}

**Pacemaker** is a high-availability cluster resource manager. It achieves maximum availability for your cluster services (//resources//) by detecting and recovering from node- and resource-level failures by making use of the messaging and membership capabilities provided by Corosync. It can do this for clusters of practically any size and comes with a powerful dependency model that allows the administrator to accurately express the relationships (both ordering and location) between the cluster resources. Virtually anything that can be scripted can be managed as part of a Pacemaker cluster. == Project Information == * [[License]] * [[https://clusterlabs.org/#features|Features]] * [[https://clusterlabs.org/quickstart.html|Get Pacemaker]] * [[https://clusterlabs.org/doc/|Documentation]] * [[https://clusterlabs.org/help.html|Support]] == Availability == {{:Availability}} == Example Configurations == {{:ClusterTypes}} == Architecture == See the "Cluster Architecture" section of Pacemaker Explained from the [[https://clusterlabs.org/pacemaker/doc/|Pacemaker documentation set]]. == Project History == Pacemaker came to life in late **2003** when [[http://www.advogato.org/person/lmb/diary.html|Lars]] convinced [[http://www.novell.com/linux/|SUSE]] to hire [[User:Beekhof|Andrew Beekhof]] to implement a new cluster resource manager (CRM) for the Heartbeat project. Although simple to configure, the old Heartbeat version 1 cluster manager had four key deficiencies: * Maximum of 2 nodes * Highly coupled design and implementation * Overly simplistic group-based resource model * Inability to detect and recover from resource-level failures In 2005, Heartbeat 2.0.0 was released containing the first public version of the new CRM. After many successful releases, the decision was made at the end of 2007 to spin off the CRM into its own project after the 2.1.3 Heartbeat release in order to: * support both the OpenAIS and Heartbeat cluster stacks equally * decouple the release cycles of two projects at very different stages of their life cycles * foster clearer package boundaries, thus leading to * better and more stable interfaces This transition was completed in 2008 with the 0.6.0 release of Pacemaker, which was the first to support both cluster stacks. The 0.6 series was derived from, and fully compatible with, the 2.1.3 CRM. The 0.6 series received bug-fix-only updates throughout 2008 and 2009 before being deprecated in March 2010. The Pacemaker 1.0 series contained many improvements, including: * A more intuitive syntax * Failure (migration) thresholds and timeouts * Tool for making offline configuration changes * A unified command line configuration tool that hides the underlying XML * Rules, instance_attributes, meta_attributes and sets of operations can be defined once and referenced in multiple places * The ability to connect to the CIB from non-cluster machines * Allow recurring actions to be triggered at known times * A more powerful RelaxNG-based configuration schema

**Pacemaker** is a high-availability cluster resource manager. It achieves maximum availability for your cluster services (//resources//) by detecting and recovering from node- and resource-level failures by making use of the messaging and membership capabilities provided by Corosync. It can do this for clusters of practically any size and comes with a powerful dependency model that allows the administrator to accurately express the relationships (both ordering and location) between the cluster resources. Virtually anything that can be scripted can be managed as part of a Pacemaker cluster. == Project Information == * [[License]] * [[https://clusterlabs.org/#features|Features]] * [[https://clusterlabs.org/quickstart.html|Get Pacemaker]] * [[https://clusterlabs.org/doc/|Documentation]] * [[https://clusterlabs.org/help.html|Support]] == Availability == {{:Availability}} == Example Configurations == {{:ClusterTypes}} == Architecture == See the "Cluster Architecture" section of Pacemaker Explained from the [[https://clusterlabs.org/pacemaker/doc/|Pacemaker documentation set]]. == Project History == {{:Project History}}Pacemaker came to life in late **2003** when [[http://www.advogato.org/person/lmb/diary.html|Lars]] convinced [[http://www.novell.com/linux/|SUSE]] to hire [[User:Beekhof|Andrew Beekhof]] to implement a new cluster resource manager (CRM) for the Heartbeat project. Although simple to configure, the old Heartbeat version 1 cluster manager had four key deficiencies: * Maximum of 2 nodes * Highly coupled design and implementation * Overly simplistic group-based resource model * Inability to detect and recover from resource-level failures In 2005, Heartbeat 2.0.0 was released containing the first public version of the new CRM. After many successful releases, the decision was made at the end of 2007 to spin off the CRM into its own project after the 2.1.3 Heartbeat release in order to: * support both the OpenAIS and Heartbeat cluster stacks equally * decouple the release cycles of two projects at very different stages of their life cycles * foster clearer package boundaries, thus leading to * better and more stable interfaces This transition was completed in 2008 with the 0.6.0 release of Pacemaker, which was the first to support both cluster stacks. The 0.6 series was derived from, and fully compatible with, the 2.1.3 CRM. The 0.6 series received bug-fix-only updates throughout 2008 and 2009 before being deprecated in March 2010. The Pacemaker 1.0 series contained many improvements, including: * A more intuitive syntax * Failure (migration) thresholds and timeouts * Tool for making offline configuration changes * A unified command line configuration tool that hides the underlying XML * Rules, instance_attributes, meta_attributes and sets of operations can be defined once and referenced in multiple places * The ability to connect to the CIB from non-cluster machines * Allow recurring actions to be triggered at known times * A more powerful RelaxNG-based configuration schema