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 java.lang.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 Summary

Modifier and Type	Method	Description
void	advanceClientStateId(java.lang.Long clientStateId)
long	getLastSeenStateId()
long	getPoolLocalStateId()
boolean	isCoordinatedCall(java.lang.String protocolName, java.lang.String method)
long	receiveRequestState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcRequestHeaderProto header, long threshold)	Client side implementation only provides state alignment info in requests.
void	receiveResponseState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto header)	Router updates a globally shared value using response from namenodes.
void	updateRequestState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcRequestHeaderProto.Builder header)	Client side implementation for routers to provide state info in requests to namenodes.
void	updateResponseState(org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto.Builder header)	Client side implementation only receives state alignment info.

Methods inherited from class java.lang.Object

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

Method Detail

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 java.io.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:

java.io.IOException

getLastSeenStateId

public long getLastSeenStateId()

Specified by:

getLastSeenStateId in interface org.apache.hadoop.ipc.AlignmentContext

isCoordinatedCall

public boolean isCoordinatedCall(java.lang.String protocolName,
                                 java.lang.String method)

Specified by:

isCoordinatedCall in interface org.apache.hadoop.ipc.AlignmentContext

advanceClientStateId

public void advanceClientStateId(java.lang.Long clientStateId)

getPoolLocalStateId

@VisibleForTesting
public long getPoolLocalStateId()