org.apache.hadoop.hbase.master.assignment.UnassignProcedure Maven / Gradle / Ivy
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/**
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.master.assignment;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.NotServingRegionException;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.exceptions.UnexpectedStateException;
import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
import org.apache.hadoop.hbase.master.RegionState.State;
import org.apache.hadoop.hbase.master.assignment.RegionStates.RegionStateNode;
import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
import org.apache.hadoop.hbase.master.procedure.RSProcedureDispatcher.RegionCloseOperation;
import org.apache.hadoop.hbase.master.procedure.ServerCrashException;
import org.apache.hadoop.hbase.procedure2.ProcedureMetrics;
import org.apache.hadoop.hbase.procedure2.ProcedureStateSerializer;
import org.apache.hadoop.hbase.procedure2.RemoteProcedureDispatcher.RemoteOperation;
import org.apache.hadoop.hbase.regionserver.RegionServerAbortedException;
import org.apache.hadoop.hbase.regionserver.RegionServerStoppedException;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionTransitionState;
import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.UnassignRegionStateData;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
/**
* Procedure that describes the unassignment of a single region.
* There can only be one RegionTransitionProcedure -- i.e. an assign or an unassign -- per region
* running at a time, since each procedure takes a lock on the region.
*
* The Unassign starts by placing a "close region" request in the Remote Dispatcher
* queue, and the procedure will then go into a "waiting state" (suspend).
* The Remote Dispatcher will batch the various requests for that server and
* they will be sent to the RS for execution.
* The RS will complete the open operation by calling master.reportRegionStateTransition().
* The AM will intercept the transition report, and notify this procedure.
* The procedure will wakeup and finish the unassign by publishing its new state on meta.
*
If we are unable to contact the remote regionserver whether because of ConnectException
* or socket timeout, we will call expire on the server we were trying to contact. We will remain
* in suspended state waiting for a wake up from the ServerCrashProcedure that is processing the
* failed server. The basic idea is that if we notice a crashed server, then we have a
* responsibility; i.e. we should not let go of the region until we are sure the server that was
* hosting has had its crash processed. If we let go of the region before then, an assign might
* run before the logs have been split which would make for data loss.
*
*
TODO: Rather than this tricky coordination between SCP and this Procedure, instead, work on
* returning a SCP as our subprocedure; probably needs work on the framework to do this,
* especially if the SCP already created.
*/
@InterfaceAudience.Private
public class UnassignProcedure extends RegionTransitionProcedure {
private static final Log LOG = LogFactory.getLog(UnassignProcedure.class);
/**
* Where to send the unassign RPC.
*/
protected volatile ServerName hostingServer;
/**
* The Server we will subsequently assign the region too (can be null).
*/
protected volatile ServerName destinationServer;
// TODO: should this be in a reassign procedure?
// ...and keep unassign for 'disable' case?
private boolean force;
public UnassignProcedure() {
// Required by the Procedure framework to create the procedure on replay
super();
}
public UnassignProcedure(final RegionInfo regionInfo, final ServerName hostingServer,
final boolean force) {
this(regionInfo, hostingServer, null, force);
}
public UnassignProcedure(final RegionInfo regionInfo,
final ServerName hostingServer, final ServerName destinationServer, final boolean force) {
super(regionInfo);
this.hostingServer = hostingServer;
this.destinationServer = destinationServer;
this.force = force;
// we don't need REGION_TRANSITION_QUEUE, we jump directly to sending the request
setTransitionState(RegionTransitionState.REGION_TRANSITION_DISPATCH);
}
@Override
public TableOperationType getTableOperationType() {
return TableOperationType.REGION_UNASSIGN;
}
@Override
protected boolean isRollbackSupported(final RegionTransitionState state) {
switch (state) {
case REGION_TRANSITION_QUEUE:
case REGION_TRANSITION_DISPATCH:
return true;
default:
return false;
}
}
@Override
protected void serializeStateData(ProcedureStateSerializer serializer)
throws IOException {
UnassignRegionStateData.Builder state = UnassignRegionStateData.newBuilder()
.setTransitionState(getTransitionState())
.setHostingServer(ProtobufUtil.toServerName(this.hostingServer))
.setRegionInfo(ProtobufUtil.toRegionInfo(getRegionInfo()));
if (this.destinationServer != null) {
state.setDestinationServer(ProtobufUtil.toServerName(destinationServer));
}
if (force) {
state.setForce(true);
}
serializer.serialize(state.build());
}
@Override
protected void deserializeStateData(ProcedureStateSerializer serializer)
throws IOException {
final UnassignRegionStateData state =
serializer.deserialize(UnassignRegionStateData.class);
setTransitionState(state.getTransitionState());
setRegionInfo(ProtobufUtil.toRegionInfo(state.getRegionInfo()));
this.hostingServer = ProtobufUtil.toServerName(state.getHostingServer());
force = state.getForce();
if (state.hasDestinationServer()) {
this.destinationServer = ProtobufUtil.toServerName(state.getDestinationServer());
}
}
@Override
protected boolean startTransition(final MasterProcedureEnv env, final RegionStateNode regionNode) {
// nothing to do here. we skip the step in the constructor
// by jumping to REGION_TRANSITION_DISPATCH
throw new UnsupportedOperationException();
}
@Override
protected boolean updateTransition(final MasterProcedureEnv env, final RegionStateNode regionNode)
throws IOException {
// if the region is already closed or offline we can't do much...
if (regionNode.isInState(State.CLOSED, State.OFFLINE)) {
LOG.info("Not unassigned " + this + "; " + regionNode.toShortString());
return false;
}
// if we haven't started the operation yet, we can abort
if (aborted.get() && regionNode.isInState(State.OPEN)) {
setAbortFailure(getClass().getSimpleName(), "abort requested");
return false;
}
// Mark the region as CLOSING.
env.getAssignmentManager().markRegionAsClosing(regionNode);
// Add the close region operation the the server dispatch queue.
if (!addToRemoteDispatcher(env, regionNode.getRegionLocation())) {
// If addToRemoteDispatcher fails, it calls the callback #remoteCallFailed.
}
// Return true to keep the procedure running.
return true;
}
@Override
protected void finishTransition(final MasterProcedureEnv env, final RegionStateNode regionNode)
throws IOException {
env.getAssignmentManager().markRegionAsClosed(regionNode);
}
@Override
public RemoteOperation remoteCallBuild(final MasterProcedureEnv env, final ServerName serverName) {
assert serverName.equals(getRegionState(env).getRegionLocation());
return new RegionCloseOperation(this, getRegionInfo(), this.destinationServer);
}
@Override
protected void reportTransition(final MasterProcedureEnv env, final RegionStateNode regionNode,
final TransitionCode code, final long seqId) throws UnexpectedStateException {
switch (code) {
case CLOSED:
setTransitionState(RegionTransitionState.REGION_TRANSITION_FINISH);
break;
default:
throw new UnexpectedStateException(String.format(
"Received report unexpected transition state=%s for region=%s server=%s, expected CLOSED.",
code, regionNode.getRegionInfo(), regionNode.getRegionLocation()));
}
}
@Override
protected boolean remoteCallFailed(final MasterProcedureEnv env, final RegionStateNode regionNode,
final IOException exception) {
// TODO: Is there on-going rpc to cleanup?
if (exception instanceof ServerCrashException) {
// This exception comes from ServerCrashProcedure after log splitting.
// SCP found this region as a RIT. Its call into here says it is ok to let this procedure go
// on to a complete close now. This will release lock on this region so subsequent action on
// region can succeed; e.g. the assign that follows this unassign when a move (w/o wait on SCP
// the assign could run w/o logs being split so data loss).
try {
reportTransition(env, regionNode, TransitionCode.CLOSED, HConstants.NO_SEQNUM);
} catch (UnexpectedStateException e) {
// Should never happen.
throw new RuntimeException(e);
}
} else if (exception instanceof RegionServerAbortedException ||
exception instanceof RegionServerStoppedException ||
exception instanceof ServerNotRunningYetException) {
// TODO
// RS is aborting, we cannot offline the region since the region may need to do WAL
// recovery. Until we see the RS expiration, we should retry.
// TODO: This should be suspend like the below where we call expire on server?
LOG.info("Ignoring; waiting on ServerCrashProcedure", exception);
} else if (exception instanceof NotServingRegionException) {
LOG.info("IS THIS OK? ANY LOGS TO REPLAY; ACTING AS THOUGH ALL GOOD " + regionNode,
exception);
setTransitionState(RegionTransitionState.REGION_TRANSITION_FINISH);
} else {
LOG.warn("Expiring server " + this + "; " + regionNode.toShortString() +
", exception=" + exception);
env.getMasterServices().getServerManager().expireServer(regionNode.getRegionLocation());
// Return false so this procedure stays in suspended state. It will be woken up by a
// ServerCrashProcedure when it notices this RIT.
// TODO: Add a SCP as a new subprocedure that we now come to depend on.
return false;
}
return true;
}
@Override
public void toStringClassDetails(StringBuilder sb) {
super.toStringClassDetails(sb);
sb.append(", server=").append(this.hostingServer);
}
@Override
public ServerName getServer(final MasterProcedureEnv env) {
return this.hostingServer;
}
@Override
protected ProcedureMetrics getProcedureMetrics(MasterProcedureEnv env) {
return env.getAssignmentManager().getAssignmentManagerMetrics().getUnassignProcMetrics();
}
}