Package org.apache.flink.runtime.leaderelection

Class StandaloneLeaderElection

java.lang.Object

org.apache.flink.runtime.leaderelection.StandaloneLeaderElection

All Implemented Interfaces:

AutoCloseable, LeaderElection

public class StandaloneLeaderElection
extends Object
implements LeaderElection

StandaloneLeaderElection implements LeaderElection for non-HA cases. This implementation can be used for testing, and for cluster setups that do not tolerate failures of the main components (e.g. ResourceManager or Dispatcher).

Constructor Summary

Constructors

Constructor	Description
StandaloneLeaderElection(UUID sessionID)

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the LeaderElection by deregistering the LeaderContender from the underlying leader election.
CompletableFuture<Void>	confirmLeadershipAsync(UUID leaderSessionID, String leaderAddress)	Confirms that the LeaderContender has accepted the leadership identified by the given leader session id.
CompletableFuture<Boolean>	hasLeadershipAsync(UUID leaderSessionId)	Returns true if the service's LeaderContender has the leadership under the given leader session ID acquired.
void	startLeaderElection(LeaderContender contender)	Registers the passed LeaderContender with the leader election process.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

StandaloneLeaderElection

public StandaloneLeaderElection(UUID sessionID)

Method Details

startLeaderElection

public void startLeaderElection(LeaderContender contender)
                         throws Exception

Description copied from interface: LeaderElection

Registers the passed LeaderContender with the leader election process.

Specified by:

startLeaderElection in interface LeaderElection

Throws:

Exception

confirmLeadershipAsync

public CompletableFuture<Void> confirmLeadershipAsync(UUID leaderSessionID,
 String leaderAddress)

Description copied from interface: LeaderElection

Confirms that the LeaderContender has accepted the leadership identified by the given leader session id. It also publishes the leader address under which the leader is reachable.

The data is only confirmed if the leadership is still acquired.

The intention of this method is to establish an order between setting the new leader session ID in the LeaderContender and publishing the new leader session ID and the related leader address to the leader retrieval services.

Specified by:

confirmLeadershipAsync in interface LeaderElection

Parameters:

leaderSessionID - The new leader session ID

leaderAddress - The address of the new leader

hasLeadershipAsync

public CompletableFuture<Boolean> hasLeadershipAsync(UUID leaderSessionId)

Description copied from interface: LeaderElection

Returns true if the service's LeaderContender has the leadership under the given leader session ID acquired.

Specified by:

hasLeadershipAsync in interface LeaderElection

Parameters:

leaderSessionId - identifying the current leader

Returns:

true if the associated LeaderContender is the leader, otherwise false

close

public void close()
           throws Exception

Description copied from interface: LeaderElection

Closes the LeaderElection by deregistering the LeaderContender from the underlying leader election. LeaderContender.revokeLeadership() will be called if the service still holds the leadership.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface LeaderElection

Throws:

Exception