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2.2.4.3. Malfunctions of the Replication Live Server

Malfunctions that occur on the Replication Live Server can affect two components:

  • replication: Replication is interrupted and the content of the Replication Live Server becomes outdated depending on the publication activity of the Content Management Server. After restart, the Replication Live Server continues replication at precisely the point where it was interrupted and will only go online when its content is up to date.

  • Content Application Engines: Not running CAEs fail to start and running CAEs return errors when requesting the Replication Live Server. After restart, CAEs can reconnect. They don't need to be restarted.

Replication Live Server Failure
Error behavior All CAEs connected to the Replication Live Server receive connection error responses from the server.
Error correction The watchdog of the Replication Live Server detects the failure and restarts the server (see the watchdog and Replication Live Server logs). As soon as the Replication Live Server is online again, the CAEs are working properly again.

Table 2.4. Slave Live Server failure


Replication Live Server Database Failure
Error behavior Transactions which are active at the time of failure or which first notice the failure are terminated with an error. The error is passed to the server and clients. A replicator client is terminated. Requests to CAE clients fail with an error. Transactions started after the server has detected the database failure are blocked until a new database connection is created. Requests to CAEs are paused. Appropriate messages are written to the server log.
Error correction Because a database failure can lead to erroneously generated pages or blocked requests, the watchdog restarts the Replication Live Server. In the meantime the second Replication Live Server takes over the task of the first one. Restarting the Replication Live Server implies a brief process failure. In its initialization phase, the Replication Live Server will remain paused, until the database is available again (see server log). The CAEs cannot log on in this state.

Table 2.5. Database failure