Package weblogic.server

Interface ServerService

All Superinterfaces:

ServerStates

@Contract
public interface ServerService
extends ServerStates

Server services that need to hook into the servers lifecycle implement this interface. The implementation classname is then added to the weblogic.t3.srvr.ServerServices. Please refer to the javadoc of weblogic.t3.srvr.ServerServices for more information on when start, stop and halt are called.

Field Summary

Fields inherited from interface weblogic.server.ServerStates

ACTIVATE_LATER, ADMIN, FAILED, FAILED_NOT_RESTARTABLE, FAILED_RESTARTING, FORCE_SHUTTING_DOWN, FORCE_SUSPENDING, RESUMING, RUNNING, SHUTDOWN, SHUTDOWN_IN_PROCESS, SHUTDOWN_PENDING, SHUTTING_DOWN, STANDBY, STARTING, SUSPENDING, UNKNOWN

Method Summary

Modifier and Type	Method	Description
java.lang.String	getName()	Get the name of the server service.
java.lang.String	getVersion()	Get a comma separated list of specification versions that this server service implements.
void	halt()	This method shuts down the service by cancelling or rolling back inflight work.
void	start()	This method starts the service.
void	stop()	This method gracefully shuts down the service completing inflight work and releasing resources.

Method Detail

getName

java.lang.String getName()

Get the name of the server service. This name is displayed externally in utilities like weblogic.version and also during server startup.

getVersion

java.lang.String getVersion()

Get a comma separated list of specification versions that this server service implements. The version information is displayed to customers through weblogic.version and other utilities.

start

void start()
    throws ServiceFailureException

This method starts the service. The service is fully functioning and available to other services after this method returns. This is a blocking operation. The service should return only after it has started. It should throw ServiceFailureException if it is unable to complete the start operation.

This method can be called more than once but not concurrently. Here are the conditions under which start() can be called:

During server startup After stop completes without exception After halt completes without exception After halt completes without exception even when a preceding stop threw an exception

Throws:

ServiceFailureException - service is unable to start due to an internal error condition. The service is not available if this exception is thrown. The service should cleanup its state before throwing this exception. No further callbacks will be issued after this exception is thrown.

stop

void stop()
   throws ServiceFailureException

This method gracefully shuts down the service completing inflight work and releasing resources. The method should block till the operation is complete. The service should fully stop before returning without relying on a subsequent halt() call. Here is a broad definition of inflight work:

"work associated with state that will be lost if this service becomes unavailable. Remote and/or local users are relying on this state to complete their work. The user can be another ServerService, a remote EJB client, browser request etc. If the state is replicated to another cluster node or is persistent and available to other nodes then work accessing such state is not treated as inflight work. Note that work would be treated as inflight till replication or persistence is complete."

There is always a danger that completing inflight work can take forever. The caller of this method is expected to handle that condition. For e.g. graceful shutdown provides a timeout after which force shutdown begins.

Services should handle a halt() call even when stop() is executing.

This method can be called more than once but not concurrently. Here are the conditions under which stop() can be called:

After start completes without exception and the service is running. While halt is in progress. stop should quit by throwing a ServiceFailureException. stop and halt called simultaneouly. Should allow halt to proceed. stop should quit by throwing a ServiceFailureException. After service is already shutdown due to a previous stop or halt. Should just return without exception.