HP Serviceguard
An MC / ServiceGuard cluster is a cluster manager from Hewlett-Packard that provides high availability of computer systems in the form of an active / passive cluster . MC stands for "multicomputer". Note: MC / ServiceGuard is the outdated term for Serviceguard (MC = multiple computer).
The applications and services running in the cluster are grouped into resource groups (packages). Should a service, a node or a network fail, Serviceguard can automatically transfer control of all system resources ( shared disk , virtual IP , services such as a database service or an application such as SAP) in a group to another node within the cluster. This means that the applications remain available with a brief interruption in system operation.
The takeover of a resource group by another cluster node in the event of a failure is known as failover . The targeted change of a resource group for the purpose of testing or for maintenance work is called switchover .
A resource group contains a virtual IP address, possibly disk space on shared storage and the associated applications (also called services). Up to 900 such services can be combined in a resource group. In turn, up to 150 resource groups can be managed in a cluster. A resource group is active on exactly one cluster node. This is where the term active / passive cluster comes from : one cluster node is active, the others are passive - at least with regard to a specific resource group.
Serviceguard replaces the previous product SwitchOver, which also enabled redundant components in computer systems. MC / ServiceGuard was first provided for HP-UX 10.0 and is also available for Linux.
See also
Cluster Manager | Failover | Switchover | Application program | High availability | Resilience