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

Class NoRouterRpcFairnessPolicyController

java.lang.Object

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

All Implemented Interfaces:

RouterRpcFairnessPolicyController

public class NoRouterRpcFairnessPolicyController
extends Object
implements RouterRpcFairnessPolicyController

A pass through fairness policy that implements RouterRpcFairnessPolicyController and allows any number of handlers to connect to any specific downstream name service.

Constructor Summary

Constructors

Constructor	Description
NoRouterRpcFairnessPolicyController(org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method	Description
boolean	acquirePermit(String nsId)	Request permission for a specific name service to continue the call and connect to downstream name node.
boolean	contains(String nsId)	Determine whether ns has registered handlers.
String	getAvailableHandlerOnPerNs()	Returns the JSON string of the available handler for each name service.
int	getAvailablePermits(String nsId)	Returns the available handler for each name service.
void	releasePermit(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

Constructor Details

NoRouterRpcFairnessPolicyController

public NoRouterRpcFairnessPolicyController(org.apache.hadoop.conf.Configuration conf)

Method Details

acquirePermit

public boolean acquirePermit(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(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

getAvailableHandlerOnPerNs

public 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.

getAvailablePermits

public int getAvailablePermits(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.

contains

public boolean contains(String nsId)

Description copied from interface: RouterRpcFairnessPolicyController

Determine whether ns has registered handlers.

Specified by:

contains in interface RouterRpcFairnessPolicyController

Parameters:

nsId - name service id.

Returns:

true if the ns has registered handlers, false in other cases.