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

Class PoolAlignmentContext

java.lang.Object
org.apache.hadoop.hdfs.server.federation.router.PoolAlignmentContext
All Implemented Interfaces:
org.apache.hadoop.ipc.AlignmentContext
public class PoolAlignmentContext extends Object implements org.apache.hadoop.ipc.AlignmentContext
An alignment context shared by all connections in a ConnectionPool. There is a distinct connection pool for each [namespace,UGI] pairing.

sharedGlobalStateId is a reference to a shared LongAccumulator object in the RouterStateIdContext. poolLocalStateId is specific to each PoolAlignmentContext.

The shared sharedGlobalStateId is updated only using responses from NameNodes, so clients cannot poison it. poolLocalStateId is used to propagate client observed state into NameNode requests. A misbehaving client can poison this but the effect is only visible to other clients with the same UGI and accessing the same namespace.

  • Method Details

    • updateResponseState

      public void updateResponseState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto.Builder header)
      Client side implementation only receives state alignment info. It does not provide state alignment info therefore this does nothing.
      Specified by:
      updateResponseState in interface org.apache.hadoop.ipc.AlignmentContext

    • receiveResponseState

      public void receiveResponseState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto header)
      Router updates a globally shared value using response from namenodes.
      Specified by:
      receiveResponseState in interface org.apache.hadoop.ipc.AlignmentContext

    • updateRequestState

      public void updateRequestState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcRequestHeaderProto.Builder header)
      Client side implementation for routers to provide state info in requests to namenodes.
      Specified by:
      updateRequestState in interface org.apache.hadoop.ipc.AlignmentContext

    • receiveRequestState

      public long receiveRequestState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcRequestHeaderProto header, long threshold) throws IOException
      Client side implementation only provides state alignment info in requests. Client does not receive RPC requests therefore this does nothing.
      Specified by:
      receiveRequestState in interface org.apache.hadoop.ipc.AlignmentContext
      Throws:
      IOException

    • getLastSeenStateId

      public long getLastSeenStateId()
      Specified by:
      getLastSeenStateId in interface org.apache.hadoop.ipc.AlignmentContext

    • isCoordinatedCall

      public boolean isCoordinatedCall(String protocolName, String method)
      Specified by:
      isCoordinatedCall in interface org.apache.hadoop.ipc.AlignmentContext

    • advanceClientStateId

      public void advanceClientStateId(Long clientStateId)

    • getPoolLocalStateId

      @VisibleForTesting public long getPoolLocalStateId()