High Availability for the PowerCenter Repository Service
Configure high availability for the PowerCenter Repository Service to minimize interruptions to data integration tasks.
The PowerCenter Repository Service has the following high availability features that are available based on your license:
- •Resilience. The PowerCenter Repository Service is resilient to the temporary unavailability of other services and the repository database. PowerCenter Repository Service clients are resilient to connections with the PowerCenter Repository Service.
- •Restart and failover. If the PowerCenter Repository Service fails, the Service Manager can restart the service or fail it over to another node, based on node availability.
- •Recovery. After restart or failover, the PowerCenter Repository Service can recover operations from the point of interruption.
Resilience
The PowerCenter Repository Service is resilient to temporary unavailability of PowerCenter Repository Service clients and the PowerCenter Repository database.
An application service can be unavailable because of network failure or because a service process fails. You can configure the resilience timeout for the connection between the PowerCenter Repository Service and the following components:
- PowerCenter Repository Service Clients
- A PowerCenter Repository Service client can be a PowerCenter Client or a PowerCenter service that depends on the PowerCenter Repository Service. For example, the PowerCenter Integration Service is a PowerCenter Repository Service client because it depends on the PowerCenter Repository Service for a connection to the repository.
- The PowerCenter Repository Service resilience timeout period is based on the resilience properties that you configure for the PowerCenter Repository Service, PowerCenter Repository Service clients, and the domain.
Note: The Web Services Hub is not resilient to the PowerCenter Repository Service.
- PowerCenter Repository Database
- The PowerCenter repository database might become unavailable because of network failure or because the repository database system becomes unavailable. If the repository database becomes unavailable, the PowerCenter Repository Service tries to reconnect to the repository database within the period specified by the database connection timeout configured in the PowerCenter Repository Service properties.
Tip: If the repository database system has high availability features, set the database connection timeout to allow the repository database system enough time to become available before the PowerCenter Repository Service tries to reconnect to it. Test the database system features that you plan to use to determine the optimum database connection timeout.
Restart and Failover
If the PowerCenter Repository Service process fails, the Service Manager can restart the process on the same node. If the node is not available, the PowerCenter Repository Service process fails over to the backup node.
The PowerCenter Repository Service process fails over to a backup node in the following situations:
- •The PowerCenter Repository Service process fails and the primary node is not available.
- •The PowerCenter Repository Service process is running on a node that fails.
- •You disable the PowerCenter Repository Service process.
After failover, PowerCenter Repository Service clients synchronize and connect to the PowerCenter Repository Service process without loss of service.
You can disable a PowerCenter Repository Service process to shut down a node for maintenance. If you disable a PowerCenter Repository Service process in complete or abort mode, the PowerCenter Repository Service process fails over to another node.
Recovery
After a PowerCenter Repository Service restarts or fails over, it restores the state of operation from the repository and recovers operations from the point of interruption.
The PowerCenter Repository Service maintains the state of operation in the repository. The state of operations includes information about repository locks, requests in progress, and connected clients.
The PowerCenter Repository Service performs the following tasks to recover operations:
- •Gets locks on repository objects, such as mappings and sessions
- •Reconnects to clients, such as the PowerCenter Designer and the PowerCenter Integration Service
- •Completes requests in progress, such as saving a mapping
- •Sends outstanding notifications about metadata changes, such as workflow schedule changes