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.procedure2; 019 020import java.util.ArrayList; 021import java.util.Collection; 022import java.util.HashSet; 023import java.util.List; 024import java.util.Set; 025import org.apache.yetus.audience.InterfaceAudience; 026import org.apache.yetus.audience.InterfaceStability; 027import org.slf4j.Logger; 028import org.slf4j.LoggerFactory; 029 030import org.apache.hadoop.hbase.shaded.protobuf.generated.ProcedureProtos.ProcedureState; 031 032/** 033 * Internal state of the ProcedureExecutor that describes the state of a "Root Procedure". A "Root 034 * Procedure" is a Procedure without parent, each subprocedure will be added to the "Root Procedure" 035 * stack (or rollback-stack). RootProcedureState is used and managed only by the ProcedureExecutor. 036 * 037 * <pre> 038 * Long rootProcId = getRootProcedureId(proc); 039 * rollbackStack.get(rootProcId).acquire(proc) 040 * rollbackStack.get(rootProcId).release(proc) 041 * ... 042 * </pre> 043 */ 044@InterfaceAudience.Private 045@InterfaceStability.Evolving 046class RootProcedureState<TEnvironment> { 047 private static final Logger LOG = LoggerFactory.getLogger(RootProcedureState.class); 048 049 private enum State { 050 RUNNING, // The Procedure is running or ready to run 051 FAILED, // The Procedure failed, waiting for the rollback executing 052 ROLLINGBACK, // The Procedure failed and the execution was rolledback 053 } 054 055 private Set<Procedure<TEnvironment>> subprocs = null; 056 private ArrayList<Procedure<TEnvironment>> subprocStack = null; 057 private State state = State.RUNNING; 058 private int running = 0; 059 // for some procedures such as SCP and TRSP, there is no way to rollback, so we do not need to 060 // maintain the rollback steps 061 // TODO: the rollback logic is a bit complicated, so here we will only test whether the root 062 // procedure supports rollback at the very beginning, actually, lots of procedure can only 063 // rollback at the pre check step, after that there is no rollback too, we should try to support 064 // this too. 065 private boolean rollbackSupported; 066 067 protected synchronized boolean isFailed() { 068 switch (state) { 069 case ROLLINGBACK: 070 case FAILED: 071 return true; 072 default: 073 break; 074 } 075 return false; 076 } 077 078 protected synchronized boolean isRollingback() { 079 return state == State.ROLLINGBACK; 080 } 081 082 /** 083 * Called by the ProcedureExecutor to mark rollback execution 084 */ 085 protected synchronized boolean setRollback() { 086 if (running == 0 && state == State.FAILED) { 087 state = State.ROLLINGBACK; 088 return true; 089 } 090 return false; 091 } 092 093 /** 094 * Called by the ProcedureExecutor to mark rollback execution 095 */ 096 protected synchronized void unsetRollback() { 097 assert state == State.ROLLINGBACK; 098 state = State.FAILED; 099 } 100 101 protected synchronized void setRollbackSupported(boolean rollbackSupported) { 102 this.rollbackSupported = rollbackSupported; 103 } 104 105 protected synchronized boolean isRollbackSupported() { 106 return rollbackSupported; 107 } 108 109 protected synchronized long[] getSubprocedureIds() { 110 if (subprocs == null) { 111 return null; 112 } 113 return subprocs.stream().mapToLong(Procedure::getProcId).toArray(); 114 } 115 116 protected synchronized Collection<Procedure<TEnvironment>> getSubprocs() { 117 return subprocs; 118 } 119 120 protected synchronized List<Procedure<TEnvironment>> getSubproceduresStack() { 121 return subprocStack; 122 } 123 124 protected synchronized RemoteProcedureException getException() { 125 if (subprocs != null) { 126 for (Procedure<TEnvironment> proc : subprocs) { 127 if (proc.hasException()) { 128 return proc.getException(); 129 } 130 } 131 } 132 return null; 133 } 134 135 /** 136 * Called by the ProcedureExecutor to mark the procedure step as running. 137 */ 138 protected synchronized boolean acquire(Procedure<TEnvironment> proc) { 139 if (state != State.RUNNING) { 140 return false; 141 } 142 143 running++; 144 return true; 145 } 146 147 /** 148 * Called by the ProcedureExecutor to mark the procedure step as finished. 149 */ 150 protected synchronized void release(Procedure<TEnvironment> proc) { 151 running--; 152 } 153 154 protected synchronized void abort() { 155 if (state == State.RUNNING) { 156 state = State.FAILED; 157 } 158 } 159 160 /** 161 * Called by the ProcedureExecutor after the procedure step is completed, to add the step to the 162 * rollback list (or procedure stack). 163 * <p> 164 * Return whether we successfully added the rollback step. If the root procedure has already 165 * crossed the PONR, we do not need to maintain the rollback step, 166 */ 167 protected synchronized boolean addRollbackStep(Procedure<TEnvironment> proc) { 168 if (proc.isFailed()) { 169 state = State.FAILED; 170 } 171 if (!rollbackSupported) { 172 // just record executed, skip adding rollback step 173 proc.setExecuted(); 174 return false; 175 } 176 if (subprocStack == null) { 177 subprocStack = new ArrayList<>(); 178 } 179 proc.addStackIndex(subprocStack.size()); 180 LOG.trace("Add procedure {} as the {}th rollback step", proc, subprocStack.size()); 181 subprocStack.add(proc); 182 return true; 183 } 184 185 protected synchronized void addSubProcedure(Procedure<TEnvironment> proc) { 186 if (!proc.hasParent()) { 187 return; 188 } 189 if (subprocs == null) { 190 subprocs = new HashSet<>(); 191 } 192 subprocs.add(proc); 193 } 194 195 /** 196 * Called on store load by the ProcedureExecutor to load part of the stack. Each procedure has its 197 * own stack-positions. Which means we have to write to the store only the Procedure we executed, 198 * and nothing else. on load we recreate the full stack by aggregating each procedure 199 * stack-positions. 200 */ 201 protected synchronized void loadStack(Procedure<TEnvironment> proc) { 202 addSubProcedure(proc); 203 int[] stackIndexes = proc.getStackIndexes(); 204 if (stackIndexes != null) { 205 if (subprocStack == null) { 206 subprocStack = new ArrayList<>(); 207 } 208 int diff = (1 + stackIndexes[stackIndexes.length - 1]) - subprocStack.size(); 209 if (diff > 0) { 210 subprocStack.ensureCapacity(1 + stackIndexes[stackIndexes.length - 1]); 211 while (diff-- > 0) { 212 subprocStack.add(null); 213 } 214 } 215 for (int i = 0; i < stackIndexes.length; ++i) { 216 subprocStack.set(stackIndexes[i], proc); 217 } 218 } 219 if (proc.getState() == ProcedureState.ROLLEDBACK) { 220 state = State.ROLLINGBACK; 221 } else if (proc.isFailed()) { 222 state = State.FAILED; 223 } 224 } 225 226 /** 227 * Called on store load by the ProcedureExecutor to validate the procedure stack. 228 */ 229 protected synchronized boolean isValid() { 230 if (subprocStack != null) { 231 for (Procedure<TEnvironment> proc : subprocStack) { 232 if (proc == null) { 233 return false; 234 } 235 } 236 } 237 return true; 238 } 239}