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:
ProportionRouterRpcFairnessPolicyController, RouterAsyncRpcFairnessPolicyController, StaticRouterRpcFairnessPolicyController
public class AbstractRouterRpcFairnessPolicyController extends Object implements RouterRpcFairnessPolicyController
Base fairness policy that implements @RouterRpcFairnessPolicyController. Internally a map of nameservice to Semaphore is used to control permits.

  • Field Details

    • LOG

      public static final org.slf4j.Logger LOG

  • Constructor Details

    • AbstractRouterRpcFairnessPolicyController

      public AbstractRouterRpcFairnessPolicyController()

  • Method Details

    • init

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

    • 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

    • insertNameServiceWithPermits

      protected void insertNameServiceWithPermits(String nsId, int maxPermits)

    • 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.

    • 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.

    • 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.