Migrating When the Currently Active Host is Unavailable Use this migration

Setting up WebLogic Clusters 10-23

10.2.16.3.1 Migrating When the Currently Active Host is Unavailable Use this migration

procedure if a clustered Managed Server that was the active server for the migratable service crashes or becomes unreachable. This procedure purges the failed Managed Servers configuration cache. The purpose of purging the cache is to ensure that, when the failed server instance is once again available, it does not re-deploy a service that you have since migrated to another Managed Server. Purging the cache eliminates the risk that Managed Server which was previously the active host for the service uses local, out-of-date configuration data when it starts up again. 1. Disconnect the machine from the network entirely. It should not be accessible to the Administration Server or client traffic. If the machine has a dual ported disk, disconnect it. 2. Migrate the migratable services to a Managed Server instance on a different machine. The Administration Server must be running, so that it can coordinate the migration and update the activation table. ■ If you use the command line for migration, use the -sourcedown flag. ■ If you use the Console, it will ask you to make sure the source server is not going to restart. The migratable service is now available on a different Managed Server on a different machine. The following steps can be performed at leisure. 3. Perform the necessary repair or maintenance on the failed machine. 4. Reboot the machine, but do not connect it to the network. Node Manager will start as a service or daemon, and will attempt to start the Managed Servers on the machine. ■ If Managed Server Independence is enabled, the Managed Server will start, even though it cannot connect to the Administration Server. ■ If Managed Server Independence is disabled, the Managed Server will not start, because it cannot connect to the Administration Server. 5. Reconnect the machine to the network and shared storage, including dual ported disk, if applicable. 6. Restart the Node Manager daemonservice or reboot the machine, to start all remaining Managed Servers. 7. Start the Managed Server that was disabled. This is a normal start up, rather than a restart performed by Node Manager. The Administration Server must be reachable and running, so that the Managed Servers can synchronize with the migratable service activation table on the Administration Server—and hence know that it is no longer the active host of the migratable service.

10.2.17 Configure In-Memory HTTP Replication