Recovery Manager Domain (RM)

Recovery Manager (RM) is a domain which is responsible for ensuring that the resource updates for a unit of work are all committed or all backed out, including updates across multiple systems.

Resource Owners, such as File Control, are responsible for processing update requests from applications and for backing out updates. Recovery Manager provides interfaces which Resource Owners use to participate in a unit of work. So Recovery Manager coordinates the Resource Owners ensuring that they all either commit or back out the updates for a particular unit of work. Each Resource Owner protects Recovery Manager from the details of how its resources are managed.

Updates on multiple systems are also coordinated by Recovery Manager. However, since systems are connected in a variety of ways, Recovery Manager uses Recovery Manager Connectors (RMCs) to communicate with remote systems. RMCs, such as the LU 6.2 RMC, are responsible for adapting the Recovery Manager protocols to the inter-system protocols. RMCs protect Recovery Manager from the details of the various inter-system protocols.

Additionally, Recovery Manager supports failures such as a system crash, a remote connection failure, or a local resource failure (e.g. an I/O error). It also supports the forward recovery of local resources allowing them to be reconstructed to a consistent state.

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