Avoiding contention for server resources during client operations

Server resources that are used during client operations include database logs, server locks, drives, mount points, or volumes. For example, a client backup session might need a mount point, tape drive, and tape volume on which to store data. After these resources are allocated to the backup session, another client session to restore data that is on the tape volume might start. The restore session is delayed until the backup session unmounts the volume and releases it.

Resource contention has a direct effect on performance and the ability to complete an operation in a timely manner. The problem of resource contention is more critical with long-running client sessions or server processes. Because new database entries are stored in the recovery log until they are committed to the database, long-running sessions or processes can insert many of these entries under a single transaction, pinning the recovery log. A pinned recovery log prevents all transactions from applying database changes and causes server processes to run slowly.

You can schedule client sessions and server processes at different times to avoid resource contention and delays. When you are setting up schedules, you might need to prevent some server processes from starting automatically. For example, disable expiration, migration, reclamation, and duplicate-identification so that they can be scheduled later. Use administrator-command schedules to run these operations daily.