| 1 | /* |
| 2 | * Copyright 2006-2013 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.springframework.batch.core.partition.support; |
| 18 | |
| 19 | import java.util.Collection; |
| 20 | import java.util.HashMap; |
| 21 | import java.util.HashSet; |
| 22 | import java.util.Map; |
| 23 | import java.util.Map.Entry; |
| 24 | import java.util.Set; |
| 25 | |
| 26 | import org.springframework.batch.core.BatchStatus; |
| 27 | import org.springframework.batch.core.JobExecution; |
| 28 | import org.springframework.batch.core.JobExecutionException; |
| 29 | import org.springframework.batch.core.JobInstance; |
| 30 | import org.springframework.batch.core.Step; |
| 31 | import org.springframework.batch.core.StepExecution; |
| 32 | import org.springframework.batch.core.partition.StepExecutionSplitter; |
| 33 | import org.springframework.batch.core.repository.JobRepository; |
| 34 | import org.springframework.batch.item.ExecutionContext; |
| 35 | import org.springframework.beans.factory.InitializingBean; |
| 36 | import org.springframework.util.Assert; |
| 37 | |
| 38 | /** |
| 39 | * Generic implementation of {@link StepExecutionSplitter} that delegates to a |
| 40 | * {@link Partitioner} to generate {@link ExecutionContext} instances. Takes |
| 41 | * care of restartability and identifying the step executions from previous runs |
| 42 | * of the same job. The generated {@link StepExecution} instances have names |
| 43 | * that identify them uniquely in the partition. The name is constructed from a |
| 44 | * base (name of the target step) plus a suffix taken from the |
| 45 | * {@link Partitioner} identifiers, separated by a colon, e.g. |
| 46 | * <code>{step1:partition0, step1:partition1, ...}</code>. |
| 47 | * |
| 48 | * @author Dave Syer |
| 49 | * @since 2.0 |
| 50 | */ |
| 51 | public class SimpleStepExecutionSplitter implements StepExecutionSplitter, InitializingBean { |
| 52 | |
| 53 | private static final String STEP_NAME_SEPARATOR = ":"; |
| 54 | |
| 55 | private String stepName; |
| 56 | |
| 57 | private Partitioner partitioner; |
| 58 | |
| 59 | private boolean allowStartIfComplete = false; |
| 60 | |
| 61 | private JobRepository jobRepository; |
| 62 | |
| 63 | /** |
| 64 | * Default constructor for convenience in configuration. |
| 65 | */ |
| 66 | public SimpleStepExecutionSplitter() { |
| 67 | } |
| 68 | |
| 69 | /** |
| 70 | * Construct a {@link SimpleStepExecutionSplitter} from its mandatory |
| 71 | * properties. |
| 72 | * |
| 73 | * @param jobRepository the {@link JobRepository} |
| 74 | * @param allowStartIfComplete flag specifying preferences on restart |
| 75 | * @param stepName the target step name |
| 76 | * @param partitioner a {@link Partitioner} to use for generating input |
| 77 | * parameters |
| 78 | */ |
| 79 | public SimpleStepExecutionSplitter(JobRepository jobRepository, boolean allowStartIfComplete, String stepName, Partitioner partitioner) { |
| 80 | this.jobRepository = jobRepository; |
| 81 | this.allowStartIfComplete = allowStartIfComplete; |
| 82 | this.partitioner = partitioner; |
| 83 | this.stepName = stepName; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Construct a {@link SimpleStepExecutionSplitter} from its mandatory |
| 88 | * properties. |
| 89 | * |
| 90 | * @param jobRepository the {@link JobRepository} |
| 91 | * @param step the target step (a local version of it), used to extract the |
| 92 | * name and allowStartIfComplete flags |
| 93 | * @param partitioner a {@link Partitioner} to use for generating input |
| 94 | * parameters |
| 95 | * |
| 96 | * @deprecated use {@link #SimpleStepExecutionSplitter(JobRepository, boolean, String, Partitioner)} instead |
| 97 | */ |
| 98 | @Deprecated |
| 99 | public SimpleStepExecutionSplitter(JobRepository jobRepository, Step step, Partitioner partitioner) { |
| 100 | this.jobRepository = jobRepository; |
| 101 | this.allowStartIfComplete = step.isAllowStartIfComplete(); |
| 102 | this.partitioner = partitioner; |
| 103 | this.stepName = step.getName(); |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Check mandatory properties (step name, job repository and partitioner). |
| 108 | * |
| 109 | * @see InitializingBean#afterPropertiesSet() |
| 110 | */ |
| 111 | @Override |
| 112 | public void afterPropertiesSet() throws Exception { |
| 113 | Assert.state(jobRepository != null, "A JobRepository is required"); |
| 114 | Assert.state(stepName != null, "A step name is required"); |
| 115 | Assert.state(partitioner != null, "A Partitioner is required"); |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Flag to indicate that the partition target step is allowed to start if an |
| 120 | * execution is complete. Defaults to the same value as the underlying step. |
| 121 | * Set this manually to override the underlying step properties. |
| 122 | * |
| 123 | * @see Step#isAllowStartIfComplete() |
| 124 | * |
| 125 | * @param allowStartIfComplete the value to set |
| 126 | */ |
| 127 | public void setAllowStartIfComplete(boolean allowStartIfComplete) { |
| 128 | this.allowStartIfComplete = allowStartIfComplete; |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * The job repository that will be used to manage the persistence of the |
| 133 | * delegate step executions. |
| 134 | * |
| 135 | * @param jobRepository the JobRepository to set |
| 136 | */ |
| 137 | public void setJobRepository(JobRepository jobRepository) { |
| 138 | this.jobRepository = jobRepository; |
| 139 | } |
| 140 | |
| 141 | /** |
| 142 | * The {@link Partitioner} that will be used to generate step execution meta |
| 143 | * data for the target step. |
| 144 | * |
| 145 | * @param partitioner the partitioner to set |
| 146 | */ |
| 147 | public void setPartitioner(Partitioner partitioner) { |
| 148 | this.partitioner = partitioner; |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * The name of the target step that will be executed across the partitions. |
| 153 | * Mandatory with no default. |
| 154 | * |
| 155 | * @param stepName the step name to set |
| 156 | */ |
| 157 | public void setStepName(String stepName) { |
| 158 | this.stepName = stepName; |
| 159 | } |
| 160 | |
| 161 | /** |
| 162 | * @see StepExecutionSplitter#getStepName() |
| 163 | */ |
| 164 | @Override |
| 165 | public String getStepName() { |
| 166 | return this.stepName; |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * @see StepExecutionSplitter#split(StepExecution, int) |
| 171 | */ |
| 172 | @Override |
| 173 | public Set<StepExecution> split(StepExecution stepExecution, int gridSize) throws JobExecutionException { |
| 174 | |
| 175 | JobExecution jobExecution = stepExecution.getJobExecution(); |
| 176 | |
| 177 | Map<String, ExecutionContext> contexts = getContexts(stepExecution, gridSize); |
| 178 | Set<StepExecution> set = new HashSet<StepExecution>(contexts.size()); |
| 179 | |
| 180 | for (Entry<String, ExecutionContext> context : contexts.entrySet()) { |
| 181 | |
| 182 | // Make the step execution name unique and repeatable |
| 183 | String stepName = this.stepName + STEP_NAME_SEPARATOR + context.getKey(); |
| 184 | |
| 185 | StepExecution currentStepExecution = jobExecution.createStepExecution(stepName); |
| 186 | |
| 187 | boolean startable = getStartable(currentStepExecution, context.getValue()); |
| 188 | |
| 189 | if (startable) { |
| 190 | set.add(currentStepExecution); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | jobRepository.addAll(set); |
| 195 | |
| 196 | return set; |
| 197 | |
| 198 | } |
| 199 | |
| 200 | private Map<String, ExecutionContext> getContexts(StepExecution stepExecution, int gridSize) { |
| 201 | |
| 202 | ExecutionContext context = stepExecution.getExecutionContext(); |
| 203 | String key = SimpleStepExecutionSplitter.class.getSimpleName() + ".GRID_SIZE"; |
| 204 | |
| 205 | // If this is a restart we must retain the same grid size, ignoring the |
| 206 | // one passed in... |
| 207 | int splitSize = (int) context.getLong(key, gridSize); |
| 208 | context.putLong(key, splitSize); |
| 209 | |
| 210 | Map<String, ExecutionContext> result; |
| 211 | if (context.isDirty()) { |
| 212 | // The context changed so we didn't already know the partitions |
| 213 | jobRepository.updateExecutionContext(stepExecution); |
| 214 | result = partitioner.partition(splitSize); |
| 215 | } |
| 216 | else { |
| 217 | if (partitioner instanceof PartitionNameProvider) { |
| 218 | result = new HashMap<String, ExecutionContext>(); |
| 219 | Collection<String> names = ((PartitionNameProvider) partitioner).getPartitionNames(splitSize); |
| 220 | for (String name : names) { |
| 221 | /* |
| 222 | * We need to return the same keys as the original (failed) |
| 223 | * execution, but the execution contexts will be discarded |
| 224 | * so they can be empty. |
| 225 | */ |
| 226 | result.put(name, new ExecutionContext()); |
| 227 | } |
| 228 | } |
| 229 | else { |
| 230 | // If no names are provided, grab the partition again. |
| 231 | result = partitioner.partition(splitSize); |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | return result; |
| 236 | } |
| 237 | |
| 238 | private boolean getStartable(StepExecution stepExecution, ExecutionContext context) throws JobExecutionException { |
| 239 | |
| 240 | JobInstance jobInstance = stepExecution.getJobExecution().getJobInstance(); |
| 241 | String stepName = stepExecution.getStepName(); |
| 242 | StepExecution lastStepExecution = jobRepository.getLastStepExecution(jobInstance, stepName); |
| 243 | |
| 244 | boolean isRestart = (lastStepExecution != null && lastStepExecution.getStatus() != BatchStatus.COMPLETED); |
| 245 | |
| 246 | if (isRestart) { |
| 247 | stepExecution.setExecutionContext(lastStepExecution.getExecutionContext()); |
| 248 | } |
| 249 | else { |
| 250 | stepExecution.setExecutionContext(context); |
| 251 | } |
| 252 | |
| 253 | return shouldStart(allowStartIfComplete, stepExecution, lastStepExecution) || isRestart; |
| 254 | |
| 255 | } |
| 256 | |
| 257 | private boolean shouldStart(boolean allowStartIfComplete, StepExecution stepExecution, StepExecution lastStepExecution) |
| 258 | throws JobExecutionException { |
| 259 | |
| 260 | if (lastStepExecution == null) { |
| 261 | return true; |
| 262 | } |
| 263 | |
| 264 | BatchStatus stepStatus = lastStepExecution.getStatus(); |
| 265 | |
| 266 | if (stepStatus == BatchStatus.UNKNOWN) { |
| 267 | throw new JobExecutionException("Cannot restart step from UNKNOWN status. " |
| 268 | + "The last execution ended with a failure that could not be rolled back, " |
| 269 | + "so it may be dangerous to proceed. " + "Manual intervention is probably necessary."); |
| 270 | } |
| 271 | |
| 272 | if (stepStatus == BatchStatus.COMPLETED) { |
| 273 | if (!allowStartIfComplete) { |
| 274 | if (isSameJobExecution(stepExecution, lastStepExecution)) { |
| 275 | // it's always OK to start again in the same JobExecution |
| 276 | return true; |
| 277 | } |
| 278 | // step is complete, false should be returned, indicating that |
| 279 | // the step should not be started |
| 280 | return false; |
| 281 | } |
| 282 | else { |
| 283 | return true; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | if (stepStatus == BatchStatus.STOPPED || stepStatus == BatchStatus.FAILED) { |
| 288 | return true; |
| 289 | } |
| 290 | |
| 291 | if (stepStatus == BatchStatus.STARTED || stepStatus == BatchStatus.STARTING |
| 292 | || stepStatus == BatchStatus.STOPPING) { |
| 293 | throw new JobExecutionException( |
| 294 | "Cannot restart step from " |
| 295 | + stepStatus |
| 296 | + " status. " |
| 297 | + "The old execution may still be executing, so you may need to verify manually that this is the case."); |
| 298 | } |
| 299 | |
| 300 | throw new JobExecutionException("Cannot restart step from " + stepStatus + " status. " |
| 301 | + "We believe the old execution was abandoned and therefore has been marked as un-restartable."); |
| 302 | |
| 303 | } |
| 304 | |
| 305 | private boolean isSameJobExecution(StepExecution stepExecution, StepExecution lastStepExecution) { |
| 306 | if (stepExecution.getJobExecutionId()==null) { |
| 307 | return lastStepExecution.getJobExecutionId()==null; |
| 308 | } |
| 309 | return stepExecution.getJobExecutionId().equals(lastStepExecution.getJobExecutionId()); |
| 310 | } |
| 311 | |
| 312 | } |