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Server functionality for HBase
/*
* 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
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* 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,
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*/
package org.apache.hadoop.hbase.regionserver.handler;
import edu.umd.cs.findbugs.annotations.Nullable;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.RegionReplicaUtil;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.HRegionServer;
import org.apache.hadoop.hbase.regionserver.Region;
import org.apache.hadoop.hbase.regionserver.RegionServerServices.PostOpenDeployContext;
import org.apache.hadoop.hbase.regionserver.RegionServerServices.RegionStateTransitionContext;
import org.apache.hadoop.hbase.util.RetryCounter;
import org.apache.hadoop.hbase.util.ServerRegionReplicaUtil;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
/**
* Handles opening of a region on a region server.
*
* Just done the same thing with the old {@link OpenRegionHandler}, with some modifications on
* fencing and retrying. But we need to keep the {@link OpenRegionHandler} as is to keep compatible
* with the zk less assignment for 1.x, otherwise it is not possible to do rolling upgrade.
*/
@InterfaceAudience.Private
public class AssignRegionHandler extends EventHandler {
private static final Logger LOG = LoggerFactory.getLogger(AssignRegionHandler.class);
private final RegionInfo regionInfo;
private final long openProcId;
private final TableDescriptor tableDesc;
private final long masterSystemTime;
private final RetryCounter retryCounter;
public AssignRegionHandler(HRegionServer server, RegionInfo regionInfo, long openProcId,
@Nullable TableDescriptor tableDesc, long masterSystemTime, EventType eventType) {
super(server, eventType);
this.regionInfo = regionInfo;
this.openProcId = openProcId;
this.tableDesc = tableDesc;
this.masterSystemTime = masterSystemTime;
this.retryCounter = HandlerUtil.getRetryCounter();
}
private HRegionServer getServer() {
return (HRegionServer) server;
}
private void cleanUpAndReportFailure(IOException error) throws IOException {
LOG.warn("Failed to open region {}, will report to master", regionInfo.getRegionNameAsString(),
error);
HRegionServer rs = getServer();
rs.getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes(), Boolean.TRUE);
if (!rs.reportRegionStateTransition(new RegionStateTransitionContext(TransitionCode.FAILED_OPEN,
HConstants.NO_SEQNUM, openProcId, masterSystemTime, regionInfo))) {
throw new IOException(
"Failed to report failed open to master: " + regionInfo.getRegionNameAsString());
}
}
@Override
public void process() throws IOException {
HRegionServer rs = getServer();
String encodedName = regionInfo.getEncodedName();
byte[] encodedNameBytes = regionInfo.getEncodedNameAsBytes();
String regionName = regionInfo.getRegionNameAsString();
Region onlineRegion = rs.getRegion(encodedName);
if (onlineRegion != null) {
LOG.warn("Received OPEN for {} which is already online", regionName);
// Just follow the old behavior, do we need to call reportRegionStateTransition? Maybe not?
// For normal case, it could happen that the rpc call to schedule this handler is succeeded,
// but before returning to master the connection is broken. And when master tries again, we
// have already finished the opening. For this case we do not need to call
// reportRegionStateTransition any more.
return;
}
Boolean previous = rs.getRegionsInTransitionInRS().putIfAbsent(encodedNameBytes, Boolean.TRUE);
if (previous != null) {
if (previous) {
// The region is opening and this maybe a retry on the rpc call, it is safe to ignore it.
LOG.info("Receiving OPEN for {} which we are already trying to OPEN" +
" - ignoring this new request for this region.", regionName);
} else {
// The region is closing. This is possible as we will update the region state to CLOSED when
// calling reportRegionStateTransition, so the HMaster will think the region is offline,
// before we actually close the region, as reportRegionStateTransition is part of the
// closing process.
long backoff = retryCounter.getBackoffTimeAndIncrementAttempts();
LOG.info(
"Receiving OPEN for {} which we are trying to close, try again after {}ms",
regionName, backoff);
rs.getExecutorService().delayedSubmit(this, backoff, TimeUnit.MILLISECONDS);
}
return;
}
LOG.info("Open {}", regionName);
HRegion region;
try {
TableDescriptor htd =
tableDesc != null ? tableDesc : rs.getTableDescriptors().get(regionInfo.getTable());
if (htd == null) {
throw new IOException("Missing table descriptor for " + regionName);
}
// pass null for the last parameter, which used to be a CancelableProgressable, as now the
// opening can not be interrupted by a close request any more.
Configuration conf = rs.getConfiguration();
TableName tn = htd.getTableName();
if (ServerRegionReplicaUtil.isMetaRegionReplicaReplicationEnabled(conf, tn)) {
if (RegionReplicaUtil.isDefaultReplica(this.regionInfo.getReplicaId())) {
// Add the hbase:meta replication source on replica zero/default.
rs.getReplicationSourceService().getReplicationManager().
addCatalogReplicationSource(this.regionInfo);
}
}
region = HRegion.openHRegion(regionInfo, htd, rs.getWAL(regionInfo), conf, rs, null);
} catch (IOException e) {
cleanUpAndReportFailure(e);
return;
}
// From here on out, this is PONR. We can not revert back. The only way to address an
// exception from here on out is to abort the region server.
rs.postOpenDeployTasks(new PostOpenDeployContext(region, openProcId, masterSystemTime));
rs.addRegion(region);
LOG.info("Opened {}", regionName);
// Cache the open region procedure id after report region transition succeed.
rs.finishRegionProcedure(openProcId);
Boolean current = rs.getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes());
if (current == null) {
// Should NEVER happen, but let's be paranoid.
LOG.error("Bad state: we've just opened {} which was NOT in transition", regionName);
} else if (!current) {
// Should NEVER happen, but let's be paranoid.
LOG.error("Bad state: we've just opened {} which was closing", regionName);
}
}
@Override
protected void handleException(Throwable t) {
LOG.warn("Fatal error occurred while opening region {}, aborting...",
regionInfo.getRegionNameAsString(), t);
// Clear any reference in getServer().getRegionsInTransitionInRS() otherwise can hold up
// regionserver abort on cluster shutdown. HBASE-23984.
getServer().getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes());
getServer().abort(
"Failed to open region " + regionInfo.getRegionNameAsString() + " and can not recover", t);
}
public static AssignRegionHandler create(HRegionServer server, RegionInfo regionInfo,
long openProcId, TableDescriptor tableDesc, long masterSystemTime) {
EventType eventType;
if (regionInfo.isMetaRegion()) {
eventType = EventType.M_RS_OPEN_META;
} else if (regionInfo.getTable().isSystemTable() ||
(tableDesc != null && tableDesc.getPriority() >= HConstants.ADMIN_QOS)) {
eventType = EventType.M_RS_OPEN_PRIORITY_REGION;
} else {
eventType = EventType.M_RS_OPEN_REGION;
}
return new AssignRegionHandler(server, regionInfo, openProcId, tableDesc, masterSystemTime,
eventType);
}
}