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

Class RouterAsyncRpcFairnessPolicyController

java.lang.Object

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

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

All Implemented Interfaces:

RouterRpcFairnessPolicyController

public class RouterAsyncRpcFairnessPolicyController
extends AbstractRouterRpcFairnessPolicyController

When router async rpc enabled, it is recommended to use this fairness controller.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	INIT_MSG

Constructor Summary

Constructors

Constructor	Description
RouterAsyncRpcFairnessPolicyController(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.
void	init(org.apache.hadoop.conf.Configuration conf)
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.

Methods inherited from class org.apache.hadoop.hdfs.server.federation.fairness.AbstractRouterRpcFairnessPolicyController

contains, getAvailableHandlerOnPerNs, getAvailablePermits, insertNameServiceWithPermits, shutdown

Methods inherited from class java.lang.Object

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

Field Details

INIT_MSG

public static final String INIT_MSG

See Also:

• Constant Field Values

Constructor Details

RouterAsyncRpcFairnessPolicyController

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

Method Details

init

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

Overrides:

init in class AbstractRouterRpcFairnessPolicyController

Throws:

IllegalArgumentException

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

Overrides:

acquirePermit in class AbstractRouterRpcFairnessPolicyController

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

Overrides:

releasePermit in class AbstractRouterRpcFairnessPolicyController

Parameters:

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