001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.apache.hadoop.hbase.regionserver.handler; 019 020import edu.umd.cs.findbugs.annotations.Nullable; 021import java.io.IOException; 022import java.util.concurrent.TimeUnit; 023import org.apache.hadoop.conf.Configuration; 024import org.apache.hadoop.hbase.HConstants; 025import org.apache.hadoop.hbase.client.RegionInfo; 026import org.apache.hadoop.hbase.client.TableDescriptor; 027import org.apache.hadoop.hbase.executor.EventHandler; 028import org.apache.hadoop.hbase.executor.EventType; 029import org.apache.hadoop.hbase.regionserver.HRegion; 030import org.apache.hadoop.hbase.regionserver.HRegionServer; 031import org.apache.hadoop.hbase.regionserver.Region; 032import org.apache.hadoop.hbase.regionserver.RegionServerServices.PostOpenDeployContext; 033import org.apache.hadoop.hbase.regionserver.RegionServerServices.RegionStateTransitionContext; 034import org.apache.hadoop.hbase.util.RetryCounter; 035import org.apache.yetus.audience.InterfaceAudience; 036import org.slf4j.Logger; 037import org.slf4j.LoggerFactory; 038 039import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode; 040 041/** 042 * Handles opening of a region on a region server. 043 * <p/> 044 * Just done the same thing with the old {@link OpenRegionHandler}, with some modifications on 045 * fencing and retrying. But we need to keep the {@link OpenRegionHandler} as is to keep compatible 046 * with the zk less assignment for 1.x, otherwise it is not possible to do rolling upgrade. 047 */ 048@InterfaceAudience.Private 049public class AssignRegionHandler extends EventHandler { 050 051 private static final Logger LOG = LoggerFactory.getLogger(AssignRegionHandler.class); 052 053 private final RegionInfo regionInfo; 054 055 private final long openProcId; 056 057 private final TableDescriptor tableDesc; 058 059 private final long masterSystemTime; 060 061 private final RetryCounter retryCounter; 062 063 public AssignRegionHandler(HRegionServer server, RegionInfo regionInfo, long openProcId, 064 @Nullable TableDescriptor tableDesc, long masterSystemTime, EventType eventType) { 065 super(server, eventType); 066 this.regionInfo = regionInfo; 067 this.openProcId = openProcId; 068 this.tableDesc = tableDesc; 069 this.masterSystemTime = masterSystemTime; 070 this.retryCounter = HandlerUtil.getRetryCounter(); 071 } 072 073 private HRegionServer getServer() { 074 return (HRegionServer) server; 075 } 076 077 private void cleanUpAndReportFailure(IOException error) throws IOException { 078 LOG.warn("Failed to open region {}, will report to master", regionInfo.getRegionNameAsString(), 079 error); 080 HRegionServer rs = getServer(); 081 rs.getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes(), Boolean.TRUE); 082 if ( 083 !rs.reportRegionStateTransition(new RegionStateTransitionContext(TransitionCode.FAILED_OPEN, 084 HConstants.NO_SEQNUM, openProcId, masterSystemTime, regionInfo)) 085 ) { 086 throw new IOException( 087 "Failed to report failed open to master: " + regionInfo.getRegionNameAsString()); 088 } 089 } 090 091 @Override 092 public void process() throws IOException { 093 HRegionServer rs = getServer(); 094 String encodedName = regionInfo.getEncodedName(); 095 byte[] encodedNameBytes = regionInfo.getEncodedNameAsBytes(); 096 String regionName = regionInfo.getRegionNameAsString(); 097 Region onlineRegion = rs.getRegion(encodedName); 098 if (onlineRegion != null) { 099 LOG.warn("Received OPEN for {} which is already online", regionName); 100 // Just follow the old behavior, do we need to call reportRegionStateTransition? Maybe not? 101 // For normal case, it could happen that the rpc call to schedule this handler is succeeded, 102 // but before returning to master the connection is broken. And when master tries again, we 103 // have already finished the opening. For this case we do not need to call 104 // reportRegionStateTransition any more. 105 return; 106 } 107 Boolean previous = rs.getRegionsInTransitionInRS().putIfAbsent(encodedNameBytes, Boolean.TRUE); 108 if (previous != null) { 109 if (previous) { 110 // The region is opening and this maybe a retry on the rpc call, it is safe to ignore it. 111 LOG.info("Receiving OPEN for {} which we are already trying to OPEN" 112 + " - ignoring this new request for this region.", regionName); 113 } else { 114 // The region is closing. This is possible as we will update the region state to CLOSED when 115 // calling reportRegionStateTransition, so the HMaster will think the region is offline, 116 // before we actually close the region, as reportRegionStateTransition is part of the 117 // closing process. 118 long backoff = retryCounter.getBackoffTimeAndIncrementAttempts(); 119 LOG.info("Receiving OPEN for {} which we are trying to close, try again after {}ms", 120 regionName, backoff); 121 rs.getExecutorService().delayedSubmit(this, backoff, TimeUnit.MILLISECONDS); 122 } 123 return; 124 } 125 LOG.info("Open {}", regionName); 126 HRegion region; 127 try { 128 TableDescriptor htd = 129 tableDesc != null ? tableDesc : rs.getTableDescriptors().get(regionInfo.getTable()); 130 if (htd == null) { 131 throw new IOException("Missing table descriptor for " + regionName); 132 } 133 // pass null for the last parameter, which used to be a CancelableProgressable, as now the 134 // opening can not be interrupted by a close request any more. 135 Configuration conf = rs.getConfiguration(); 136 region = HRegion.openHRegion(regionInfo, htd, rs.getWAL(regionInfo), conf, rs, null); 137 } catch (IOException e) { 138 cleanUpAndReportFailure(e); 139 return; 140 } 141 // From here on out, this is PONR. We can not revert back. The only way to address an 142 // exception from here on out is to abort the region server. 143 rs.postOpenDeployTasks(new PostOpenDeployContext(region, openProcId, masterSystemTime)); 144 rs.addRegion(region); 145 LOG.info("Opened {}", regionName); 146 // Cache the open region procedure id after report region transition succeed. 147 rs.finishRegionProcedure(openProcId); 148 Boolean current = rs.getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes()); 149 if (current == null) { 150 // Should NEVER happen, but let's be paranoid. 151 LOG.error("Bad state: we've just opened {} which was NOT in transition", regionName); 152 } else if (!current) { 153 // Should NEVER happen, but let's be paranoid. 154 LOG.error("Bad state: we've just opened {} which was closing", regionName); 155 } 156 } 157 158 @Override 159 protected void handleException(Throwable t) { 160 LOG.warn("Fatal error occurred while opening region {}, aborting...", 161 regionInfo.getRegionNameAsString(), t); 162 // Clear any reference in getServer().getRegionsInTransitionInRS() otherwise can hold up 163 // regionserver abort on cluster shutdown. HBASE-23984. 164 getServer().getRegionsInTransitionInRS().remove(regionInfo.getEncodedNameAsBytes()); 165 getServer().abort( 166 "Failed to open region " + regionInfo.getRegionNameAsString() + " and can not recover", t); 167 } 168 169 public static AssignRegionHandler create(HRegionServer server, RegionInfo regionInfo, 170 long openProcId, TableDescriptor tableDesc, long masterSystemTime) { 171 EventType eventType; 172 if (regionInfo.isMetaRegion()) { 173 eventType = EventType.M_RS_OPEN_META; 174 } else if ( 175 regionInfo.getTable().isSystemTable() 176 || (tableDesc != null && tableDesc.getPriority() >= HConstants.ADMIN_QOS) 177 ) { 178 eventType = EventType.M_RS_OPEN_PRIORITY_REGION; 179 } else { 180 eventType = EventType.M_RS_OPEN_REGION; 181 } 182 return new AssignRegionHandler(server, regionInfo, openProcId, tableDesc, masterSystemTime, 183 eventType); 184 } 185}