Internal Switching Steps

Learn about the internal switching steps.

When you switch active and standby databases, Replication Server:

  1. Issues suspend log transfer command against the active and standby connections.

  2. Reads all messages left in the inbound queue and applies them to the standby database and, for subscription data or replicated stored procedures, to outbound queues.

    Processes all committed transactions in the inbound queue before the switch completes.

  3. Suspends the standby DSI.

  4. Places a marker in the transaction log of the new active database. Replication Server uses this marker to determine which transactions to apply to the new standby database and to any replicate databases.

  5. Stops the connection for the new active database. Purges the inbound queue and flushes the last oqid to rs_oqid table and resets rs_locator table accordingly. Resets the Replication Server segments flag and suspends the new standby DSI.

  6. Updates the ptype parameter for both new active database and standby database. Replication Server marks subscriptions that are targeted for the old active database as valid and the subscriptions in the new active database as invalid.

  7. Resumes the connection for the new active database, and resumes log transfer for the new active database so that new messages can be received. Resumes DSI for both the new active and standby databases.

Parent topic: Switching the Active and Standby Databases