org.apache.hadoop.hdfs.server.namenode.ha

Class ActiveState

java.lang.Object

org.apache.hadoop.hdfs.server.namenode.ha.HAState

org.apache.hadoop.hdfs.server.namenode.ha.ActiveState

@InterfaceAudience.Private
public class ActiveState
extends HAState

Active state of the namenode. In this state, namenode provides the namenode service and handles operations of type NameNode.OperationCategory.WRITE and NameNode.OperationCategory.READ.

Field Summary

Fields inherited from class org.apache.hadoop.hdfs.server.namenode.ha.HAState

state

Constructor Summary

Constructors

Constructor and Description
ActiveState()

Method Summary

Methods

Modifier and Type	Method and Description
void	checkOperation(HAContext context, NameNode.OperationCategory op) Check if an operation is supported in a given state.
void	enterState(HAContext context) Method to be overridden by subclasses to perform steps necessary for entering a state.
void	exitState(HAContext context) Method to be overridden by subclasses to perform steps necessary for exiting a state.
void	setState(HAContext context, HAState s) Move from the existing state to a new state
boolean	shouldPopulateReplQueues()

Methods inherited from class org.apache.hadoop.hdfs.server.namenode.ha.HAState

getServiceState, prepareToEnterState, prepareToExitState, setStateInternal, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ActiveState

public ActiveState()

Method Detail

checkOperation

public void checkOperation(HAContext context,
                  NameNode.OperationCategory op)

Description copied from class: HAState

Check if an operation is supported in a given state.

Specified by:

checkOperation in class HAState

Parameters:

context - HA context

op - Type of the operation.

shouldPopulateReplQueues

public boolean shouldPopulateReplQueues()

Specified by:

shouldPopulateReplQueues in class HAState

setState

public void setState(HAContext context,
            HAState s)
              throws ServiceFailedException

Description copied from class: HAState

Move from the existing state to a new state

Overrides:

setState in class HAState

Parameters:

context - HA context

s - new state

Throws:

ServiceFailedException - on failure to transition to new state.

enterState

public void enterState(HAContext context)
                throws ServiceFailedException

Description copied from class: HAState

Method to be overridden by subclasses to perform steps necessary for entering a state.

Specified by:

enterState in class HAState

Parameters:

context - HA context

Throws:

ServiceFailedException - on failure to enter the state.

exitState

public void exitState(HAContext context)
               throws ServiceFailedException

Description copied from class: HAState

Method to be overridden by subclasses to perform steps necessary for exiting a state.

Specified by:

exitState in class HAState

Parameters:

context - HA context

Throws:

ServiceFailedException - on failure to enter the state.