Package org.apache.hadoop.hdfs.server.federation.fairness

Class AbstractRouterRpcFairnessPolicyController

java.lang.Object

org.apache.hadoop.hdfs.server.federation.fairness.AbstractRouterRpcFairnessPolicyController

All Implemented Interfaces:

RouterRpcFairnessPolicyController

Direct Known Subclasses:

StaticRouterRpcFairnessPolicyController

public class AbstractRouterRpcFairnessPolicyController
extends java.lang.Object
implements RouterRpcFairnessPolicyController

Base fairness policy that implements @RouterRpcFairnessPolicyController. Internally a map of nameservice to Semaphore is used to control permits.

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
AbstractRouterRpcFairnessPolicyController()

Method Summary

Modifier and Type	Method	Description
boolean	acquirePermit(java.lang.String nsId)	Request permission for a specific name service to continue the call and connect to downstream name node.
java.lang.String	getAvailableHandlerOnPerNs()	Returns the JSON string of the available handler for each name service.
int	getAvailablePermits(java.lang.String nsId)	Returns the available handler for each name service.
void	init(org.apache.hadoop.conf.Configuration conf)
protected void	insertNameServiceWithPermits(java.lang.String nsId, int maxPermits)
void	releasePermit(java.lang.String nsId)	Handler threads are expected to invoke this method that signals controller to release the resources allocated to the thread for the particular name service.
void	shutdown()	Shutdown steps to stop accepting new permission requests and clean-up.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

AbstractRouterRpcFairnessPolicyController

public AbstractRouterRpcFairnessPolicyController()

Method Detail

init

public void init(org.apache.hadoop.conf.Configuration conf)

acquirePermit

public boolean acquirePermit(java.lang.String nsId)

Description copied from interface: RouterRpcFairnessPolicyController

Request permission for a specific name service to continue the call and connect to downstream name node. Controllers based on policies defined and allocations done at start-up through assignHandlersToNameservices, may provide a permission or reject the request by throwing exception.

Specified by:

acquirePermit in interface RouterRpcFairnessPolicyController

Parameters:

nsId - NS id for which a permission to continue is requested.

Returns:

true or false based on whether permit is given.

releasePermit

public void releasePermit(java.lang.String nsId)

Description copied from interface: RouterRpcFairnessPolicyController

Handler threads are expected to invoke this method that signals controller to release the resources allocated to the thread for the particular name service. This would mean permissions getting available for other handlers to request for this specific name service.

Specified by:

releasePermit in interface RouterRpcFairnessPolicyController

Parameters:

nsId - Name service id for which permission release request is made.

shutdown

public void shutdown()

Description copied from interface: RouterRpcFairnessPolicyController

Shutdown steps to stop accepting new permission requests and clean-up.

Specified by:

shutdown in interface RouterRpcFairnessPolicyController

insertNameServiceWithPermits

protected void insertNameServiceWithPermits(java.lang.String nsId,
                                            int maxPermits)

getAvailablePermits

public int getAvailablePermits(java.lang.String nsId)

Description copied from interface: RouterRpcFairnessPolicyController

Returns the available handler for each name service.

Specified by:

getAvailablePermits in interface RouterRpcFairnessPolicyController

Parameters:

nsId - name service id.

Returns:

the available handler for each name service.

getAvailableHandlerOnPerNs

public java.lang.String getAvailableHandlerOnPerNs()

Description copied from interface: RouterRpcFairnessPolicyController

Returns the JSON string of the available handler for each name service.

Specified by:

getAvailableHandlerOnPerNs in interface RouterRpcFairnessPolicyController

Returns:

the JSON string of the available handler for each name service.