Automatic failover for components

You can use EAServer Manager to mark selected components to support transparent automatic failover. If a client has an object reference for a component on a server that is a member of a cluster, the client’s object reference will provide transparent failover, unless all the servers in the cluster fail.

NoteTo avoid a single point of failure for a cluster, set the com.sybase.jaguar.cluster.startup cluster property to “check_servers.” See “Cluster start-up options” for more information.

Automatic failover is not the default for EAServer components. When a client is using a component that does not support automatic failover, and the server hosting that component fails, the client must create a new instance of that component to recover from the failure (which typically presents itself as a CORBA COMM_FAILURE system exception). However, the client does not need to create a new session, since the SessionManager::Session object supports automatic failover. The SessionManager::Session object is used implicitly by the PowerBuilder connection object and by the EAServer COM (ActiveX) proxy.

StepsSetting automatic failover for a component from EAServer Manager

  1. Locate and highlight the component you want to set.

  2. Select File | Properties.

  3. Select the Transactions tab.

  4. Select the Automatic demarcation/deactivation check box and the Autofailover check box.

  5. Click OK.