Java tutorial
/* * 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.gobblin.scheduler; import java.io.Closeable; import java.io.IOException; import java.util.Collection; import java.util.List; import java.util.Map; import java.util.Properties; import java.util.Set; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeoutException; import org.apache.commons.configuration.ConfigurationException; import org.apache.gobblin.source.Source; import org.apache.hadoop.fs.Path; import org.quartz.CronScheduleBuilder; import org.quartz.DisallowConcurrentExecution; import org.quartz.InterruptableJob; import org.quartz.Job; import org.quartz.JobBuilder; import org.quartz.JobDataMap; import org.quartz.JobDetail; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; import org.quartz.JobKey; import org.quartz.SchedulerException; import org.quartz.Trigger; import org.quartz.TriggerBuilder; import org.quartz.UnableToInterruptJobException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.base.Splitter; import com.google.common.base.Strings; import com.google.common.collect.Maps; import com.google.common.collect.Sets; import com.google.common.io.Closer; import com.google.common.util.concurrent.AbstractIdleService; import lombok.Getter; import lombok.extern.slf4j.Slf4j; import org.apache.gobblin.configuration.ConfigurationKeys; import org.apache.gobblin.runtime.JobException; import org.apache.gobblin.runtime.JobLauncher; import org.apache.gobblin.runtime.JobLauncherFactory; import org.apache.gobblin.runtime.listeners.EmailNotificationJobListener; import org.apache.gobblin.runtime.listeners.JobListener; import org.apache.gobblin.runtime.listeners.RunOnceJobListener; import org.apache.gobblin.util.ExecutorsUtils; import org.apache.gobblin.util.SchedulerUtils; import org.apache.gobblin.util.filesystem.PathAlterationObserverScheduler; /** * Gobblin job scheduler. * * <p> * The scheduler is a pure scheduler in the sense that it is only responsible * for scheduling Gobblin jobs. Job state tracking and monitoring are handled * by the {@link JobLauncher}. * </p> * * <p> * For job scheduling, This class uses a Quartz {@link org.quartz.Scheduler}. * Each job is associated with a cron schedule that is used to create a * {@link org.quartz.Trigger} for the job. * </p> * * @author Yinan Li */ public class JobScheduler extends AbstractIdleService { private static final Logger LOG = LoggerFactory.getLogger(JobScheduler.class); public enum Action { SCHEDULE, RESCHEDULE, UNSCHEDULE } public static final String JOB_SCHEDULER_KEY = "jobScheduler"; public static final String PROPERTIES_KEY = "jobProps"; public static final String JOB_LISTENER_KEY = "jobListener"; // System configuration properties public final Properties properties; // A Quartz scheduler private final SchedulerService scheduler; // A thread pool executor for running jobs without schedules protected final ExecutorService jobExecutor; // Mapping between jobs to job listeners associated with them private final Map<String, JobListener> jobListenerMap = Maps.newHashMap(); // A map for all scheduled jobs private final Map<String, JobKey> scheduledJobs = Maps.newHashMap(); // Set of supported job configuration file extensions public final Set<String> jobConfigFileExtensions; public final Path jobConfigFileDirPath; // A monitor for changes to job conf files for general FS public final PathAlterationObserverScheduler pathAlterationDetector; public final PathAlterationListenerAdaptorForMonitor listener; // A period of time for scheduler to wait until jobs are finished private final boolean waitForJobCompletion; private final Closer closer = Closer.create(); @Getter private volatile boolean cancelRequested = false; public JobScheduler(Properties properties, SchedulerService scheduler) throws Exception { this.properties = properties; this.scheduler = scheduler; this.jobExecutor = Executors.newFixedThreadPool( Integer.parseInt(properties.getProperty(ConfigurationKeys.JOB_EXECUTOR_THREAD_POOL_SIZE_KEY, Integer.toString(ConfigurationKeys.DEFAULT_JOB_EXECUTOR_THREAD_POOL_SIZE))), ExecutorsUtils.newThreadFactory(Optional.of(LOG), Optional.of("JobScheduler-%d"))); this.jobConfigFileExtensions = Sets.newHashSet(Splitter.on(",").omitEmptyStrings() .split(this.properties.getProperty(ConfigurationKeys.JOB_CONFIG_FILE_EXTENSIONS_KEY, ConfigurationKeys.DEFAULT_JOB_CONFIG_FILE_EXTENSIONS))); long pollingInterval = Long.parseLong( this.properties.getProperty(ConfigurationKeys.JOB_CONFIG_FILE_MONITOR_POLLING_INTERVAL_KEY, Long.toString(ConfigurationKeys.DEFAULT_JOB_CONFIG_FILE_MONITOR_POLLING_INTERVAL))); this.pathAlterationDetector = new PathAlterationObserverScheduler(pollingInterval); this.waitForJobCompletion = Boolean .parseBoolean(this.properties.getProperty(ConfigurationKeys.SCHEDULER_WAIT_FOR_JOB_COMPLETION_KEY, ConfigurationKeys.DEFAULT_SCHEDULER_WAIT_FOR_JOB_COMPLETION)); if (this.properties.containsKey(ConfigurationKeys.JOB_CONFIG_FILE_GENERAL_PATH_KEY)) { this.jobConfigFileDirPath = new Path( this.properties.getProperty(ConfigurationKeys.JOB_CONFIG_FILE_GENERAL_PATH_KEY)); this.listener = new PathAlterationListenerAdaptorForMonitor(jobConfigFileDirPath, this); } else { // This is needed because HelixJobScheduler does not use the same way of finding changed paths this.jobConfigFileDirPath = null; this.listener = null; } } @Override protected void startUp() throws Exception { LOG.info("Starting the job scheduler"); try { this.scheduler.awaitRunning(30, TimeUnit.SECONDS); } catch (TimeoutException | IllegalStateException exc) { throw new IllegalStateException("Scheduler service is not running."); } // Note: This should not be mandatory, gobblin-cluster modes have their own job configuration managers if (this.properties.containsKey(ConfigurationKeys.JOB_CONFIG_FILE_DIR_KEY) || this.properties.containsKey(ConfigurationKeys.JOB_CONFIG_FILE_GENERAL_PATH_KEY)) { if (this.properties.containsKey(ConfigurationKeys.JOB_CONFIG_FILE_DIR_KEY) && !this.properties.containsKey(ConfigurationKeys.JOB_CONFIG_FILE_GENERAL_PATH_KEY)) { this.properties.setProperty(ConfigurationKeys.JOB_CONFIG_FILE_GENERAL_PATH_KEY, "file://" + this.properties.getProperty(ConfigurationKeys.JOB_CONFIG_FILE_DIR_KEY)); } startServices(); } } protected void startServices() throws Exception { startGeneralJobConfigFileMonitor(); scheduleGeneralConfiguredJobs(); } @Override protected void shutDown() throws Exception { LOG.info("Stopping the job scheduler"); closer.close(); cancelRequested = true; List<JobExecutionContext> currentExecutions = this.scheduler.getScheduler().getCurrentlyExecutingJobs(); for (JobExecutionContext jobExecutionContext : currentExecutions) { try { this.scheduler.getScheduler().interrupt(jobExecutionContext.getFireInstanceId()); } catch (UnableToInterruptJobException e) { LOG.error("Failed to cancel job " + jobExecutionContext.getJobDetail().getKey(), e); } } ExecutorsUtils.shutdownExecutorService(this.jobExecutor, Optional.of(LOG)); } /** * Schedule a job. * * <p> * This method calls the Quartz scheduler to scheduler the job. * </p> * * @param jobProps Job configuration properties * @param jobListener {@link JobListener} used for callback, * can be <em>null</em> if no callback is needed. * @throws JobException when there is anything wrong * with scheduling the job */ public void scheduleJob(Properties jobProps, JobListener jobListener) throws JobException { try { scheduleJob(jobProps, jobListener, Maps.<String, Object>newHashMap(), GobblinJob.class); } catch (JobException | RuntimeException exc) { LOG.error( "Could not schedule job " + jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY, "Unknown job"), exc); } } /** * Schedule a job immediately. * * <p> * This method calls the Quartz scheduler to scheduler the job. * </p> * * @param jobProps Job configuration properties * @param jobListener {@link JobListener} used for callback, * can be <em>null</em> if no callback is needed. * @throws JobException when there is anything wrong * with scheduling the job */ public Future<?> scheduleJobImmediately(Properties jobProps, JobListener jobListener, JobLauncher jobLauncher) { Callable<Void> callable = new Callable<Void>() { @Override public Void call() throws JobException { try { runJob(jobProps, jobListener, jobLauncher); } catch (JobException je) { LOG.error("Failed to run job " + jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY), je); throw je; } return null; } }; final Future<?> future = this.jobExecutor.submit(callable); return new Future() { @Override public boolean cancel(boolean mayInterruptIfRunning) { if (!cancelRequested) { return false; } boolean result = true; try { jobLauncher.cancelJob(jobListener); } catch (JobException e) { LOG.error("Failed to cancel job " + jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY), e); result = false; } if (mayInterruptIfRunning) { result &= future.cancel(true); } return result; } @Override public boolean isCancelled() { return future.isCancelled(); } @Override public boolean isDone() { return future.isDone(); } @Override public Object get() throws InterruptedException, ExecutionException { return future.get(); } @Override public Object get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException { return future.get(timeout, unit); } }; } public Future<?> scheduleJobImmediately(Properties jobProps, JobListener jobListener) throws JobException { try { return scheduleJobImmediately(jobProps, jobListener, buildJobLauncher(jobProps)); } catch (Exception e) { throw new JobException("Job " + jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY) + " cannot be immediately scheduled.", e); } } /** * Submit a runnable to the {@link ExecutorService} of this {@link JobScheduler}. * @param runnable the runnable to submit to the job executor */ public void submitRunnableToExecutor(Runnable runnable) { this.jobExecutor.execute(runnable); } /** * Schedule a job. * * <p> * This method does what {@link #scheduleJob(Properties, JobListener)} does, and additionally it * allows the caller to pass in additional job data and the {@link Job} implementation class. * </p> * * @param jobProps Job configuration properties * @param jobListener {@link JobListener} used for callback, * can be <em>null</em> if no callback is needed. * @param additionalJobData additional job data in a {@link Map} * @param jobClass Quartz job class * @throws JobException when there is anything wrong * with scheduling the job */ public void scheduleJob(Properties jobProps, JobListener jobListener, Map<String, Object> additionalJobData, Class<? extends Job> jobClass) throws JobException { Preconditions.checkArgument(jobProps.containsKey(ConfigurationKeys.JOB_NAME_KEY), "A job must have a job name specified by job.name"); String jobName = jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY); if (this.scheduledJobs.containsKey(jobName)) { LOG.warn("Job " + jobName + " has already been scheduled"); return; } // Check if the job has been disabled boolean disabled = Boolean.valueOf(jobProps.getProperty(ConfigurationKeys.JOB_DISABLED_KEY, "false")); if (disabled) { LOG.info("Skipping disabled job " + jobName); return; } if (!jobProps.containsKey(ConfigurationKeys.JOB_SCHEDULE_KEY)) { // Submit the job to run this.jobExecutor.execute(new NonScheduledJobRunner(jobProps, jobListener)); return; } if (jobListener != null) { this.jobListenerMap.put(jobName, jobListener); } // Build a data map that gets passed to the job JobDataMap jobDataMap = new JobDataMap(); jobDataMap.put(JOB_SCHEDULER_KEY, this); jobDataMap.put(PROPERTIES_KEY, jobProps); jobDataMap.put(JOB_LISTENER_KEY, jobListener); jobDataMap.putAll(additionalJobData); // Build a Quartz job JobDetail job = JobBuilder.newJob(jobClass) .withIdentity(jobName, Strings.nullToEmpty(jobProps.getProperty(ConfigurationKeys.JOB_GROUP_KEY))) .withDescription(Strings.nullToEmpty(jobProps.getProperty(ConfigurationKeys.JOB_DESCRIPTION_KEY))) .usingJobData(jobDataMap).build(); try { // Schedule the Quartz job with a trigger built from the job configuration Trigger trigger = getTrigger(job.getKey(), jobProps); this.scheduler.getScheduler().scheduleJob(job, trigger); LOG.info(String.format("Scheduled job %s. Next run: %s.", job.getKey(), trigger.getNextFireTime())); } catch (SchedulerException se) { LOG.error("Failed to schedule job " + jobName, se); throw new JobException("Failed to schedule job " + jobName, se); } this.scheduledJobs.put(jobName, job.getKey()); } /** * Unschedule and delete a job. * * @param jobName Job name * @throws JobException when there is anything wrong unschedule the job */ public void unscheduleJob(String jobName) throws JobException { if (this.scheduledJobs.containsKey(jobName)) { try { this.scheduler.getScheduler().deleteJob(this.scheduledJobs.remove(jobName)); } catch (SchedulerException se) { LOG.error("Failed to unschedule and delete job " + jobName, se); throw new JobException("Failed to unschedule and delete job " + jobName, se); } } } /** * Run a job. * * <p> * This method runs the job immediately without going through the Quartz scheduler. * This is particularly useful for testing. * </p> * * @param jobProps Job configuration properties * @param jobListener {@link JobListener} used for callback, can be <em>null</em> if no callback is needed. * @throws JobException when there is anything wrong with running the job */ public void runJob(Properties jobProps, JobListener jobListener) throws JobException { try { runJob(jobProps, jobListener, buildJobLauncher(jobProps)); } catch (Exception e) { throw new JobException("Failed to run job " + jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY), e); } } public JobLauncher buildJobLauncher(Properties jobProps) throws Exception { return JobLauncherFactory.newJobLauncher(this.properties, jobProps); } /** * Run a job. * * <p> * This method runs the job immediately without going through the Quartz scheduler. * This is particularly useful for testing. * </p> * * <p> * This method does what {@link #runJob(Properties, JobListener)} does, and additionally it allows * the caller to pass in a {@link JobLauncher} instance used to launch the job to run. * </p> * * @param jobProps Job configuration properties * @param jobListener {@link JobListener} used for callback, can be <em>null</em> if no callback is needed. * @param jobLauncher a {@link JobLauncher} object used to launch the job to run * @return If current job is a stop-early job based on {@link Source#isEarlyStopped()} * @throws JobException when there is anything wrong with running the job */ public boolean runJob(Properties jobProps, JobListener jobListener, JobLauncher jobLauncher) throws JobException { Preconditions.checkArgument(jobProps.containsKey(ConfigurationKeys.JOB_NAME_KEY), "A job must have a job name specified by job.name"); String jobName = jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY); // Check if the job has been disabled boolean disabled = Boolean.valueOf(jobProps.getProperty(ConfigurationKeys.JOB_DISABLED_KEY, "false")); if (disabled) { LOG.info("Skipping disabled job " + jobName); return false; } // Launch the job try (Closer closer = Closer.create()) { closer.register(jobLauncher).launchJob(jobListener); boolean runOnce = Boolean.valueOf(jobProps.getProperty(ConfigurationKeys.JOB_RUN_ONCE_KEY, "false")); boolean isEarlyStopped = jobLauncher.isEarlyStopped(); if (!isEarlyStopped && runOnce && this.scheduledJobs.containsKey(jobName)) { this.scheduler.getScheduler().deleteJob(this.scheduledJobs.remove(jobName)); } return isEarlyStopped; } catch (Throwable t) { throw new JobException("Failed to launch and run job " + jobName, t); } } /** * Get the names of the scheduled jobs. * * @return names of the scheduled jobs */ public Collection<String> getScheduledJobs() { return this.scheduledJobs.keySet(); } /** * Schedule Gobblin jobs in general position */ private void scheduleGeneralConfiguredJobs() throws ConfigurationException, JobException, IOException { LOG.info("Scheduling configured jobs"); for (Properties jobProps : loadGeneralJobConfigs()) { if (!jobProps.containsKey(ConfigurationKeys.JOB_SCHEDULE_KEY)) { // A job without a cron schedule is considered a one-time job jobProps.setProperty(ConfigurationKeys.JOB_RUN_ONCE_KEY, "true"); } boolean runOnce = Boolean.valueOf(jobProps.getProperty(ConfigurationKeys.JOB_RUN_ONCE_KEY, "false")); scheduleJob(jobProps, runOnce ? new RunOnceJobListener() : new EmailNotificationJobListener()); this.listener.addToJobNameMap(jobProps); } } /** * Load job configuration file(s) from general source */ private List<Properties> loadGeneralJobConfigs() throws ConfigurationException, IOException { List<Properties> jobConfigs = SchedulerUtils.loadGenericJobConfigs(this.properties); LOG.info(String.format("Loaded %d job configurations", jobConfigs.size())); return jobConfigs; } /** * Start the job configuration file monitor using generic file system API. * * <p> * The job configuration file monitor currently only supports monitoring the following types of changes: * * <ul> * <li>New job configuration files.</li> * <li>Changes to existing job configuration files.</li> * <li>Changes to existing common properties file with a .properties extension.</li> * <li>Deletion to existing job configuration files.</li> * <li>Deletion to existing common properties file with a .properties extension.</li> * </ul> * </p> * * <p> * This monitor has one limitation: in case more than one file including at least one common properties * file are changed between two adjacent checks, the reloading of affected job configuration files may * be intermixed and applied in an order that is not desirable. This is because the order the listener * is called on the changes is not controlled by Gobblin, but instead by the monitor itself. * </p> */ private void startGeneralJobConfigFileMonitor() throws Exception { SchedulerUtils.addPathAlterationObserver(this.pathAlterationDetector, this.listener, jobConfigFileDirPath); this.pathAlterationDetector.start(); this.closer.register(new Closeable() { @Override public void close() throws IOException { try { pathAlterationDetector.stop(1000); } catch (InterruptedException e) { throw new IOException(e); } } }); } /** * Get a {@link org.quartz.Trigger} from the given job configuration properties. */ private Trigger getTrigger(JobKey jobKey, Properties jobProps) { // Build a trigger for the job with the given cron-style schedule return TriggerBuilder.newTrigger() .withIdentity(jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY), Strings.nullToEmpty(jobProps.getProperty(ConfigurationKeys.JOB_GROUP_KEY))) .forJob(jobKey) .withSchedule( CronScheduleBuilder.cronSchedule(jobProps.getProperty(ConfigurationKeys.JOB_SCHEDULE_KEY))) .build(); } /** * A Gobblin job to be scheduled. */ @DisallowConcurrentExecution @Slf4j public static class GobblinJob extends BaseGobblinJob implements InterruptableJob { @Override public void executeImpl(JobExecutionContext context) throws JobExecutionException { LOG.info("Starting job " + context.getJobDetail().getKey()); JobDataMap dataMap = context.getJobDetail().getJobDataMap(); JobScheduler jobScheduler = (JobScheduler) dataMap.get(JOB_SCHEDULER_KEY); Properties jobProps = (Properties) dataMap.get(PROPERTIES_KEY); JobListener jobListener = (JobListener) dataMap.get(JOB_LISTENER_KEY); try { jobScheduler.runJob(jobProps, jobListener); } catch (Throwable t) { throw new JobExecutionException(t); } } @Override public void interrupt() throws UnableToInterruptJobException { log.info("Job was interrupted"); } } /** * A class for running non-scheduled Gobblin jobs. */ class NonScheduledJobRunner implements Runnable { private final Properties jobProps; private final JobListener jobListener; public NonScheduledJobRunner(Properties jobProps, JobListener jobListener) { this.jobProps = jobProps; this.jobListener = jobListener; } @Override public void run() { try { JobScheduler.this.runJob(this.jobProps, this.jobListener); } catch (JobException je) { LOG.error("Failed to run job " + this.jobProps.getProperty(ConfigurationKeys.JOB_NAME_KEY), je); } } } }