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 com.pinterest.terrapin.controller; import com.google.common.collect.Lists; import com.google.common.util.concurrent.ThreadFactoryBuilder; import com.pinterest.terrapin.Constants; import com.pinterest.terrapin.TerrapinUtil; import com.pinterest.terrapin.thrift.generated.ControllerErrorCode; import com.pinterest.terrapin.thrift.generated.ControllerException; import com.pinterest.terrapin.thrift.generated.TerrapinController; import com.pinterest.terrapin.thrift.generated.TerrapinLoadRequest; import com.pinterest.terrapin.zookeeper.FileSetInfo; import com.pinterest.terrapin.zookeeper.ViewInfo; import com.pinterest.terrapin.zookeeper.ZooKeeperManager; import com.twitter.util.ExceptionalFunction0; import com.twitter.util.ExecutorServiceFuturePool; import com.twitter.util.Future; import com.twitter.util.FuturePool; import org.apache.commons.configuration.PropertiesConfiguration; import org.apache.hadoop.hdfs.DFSClient; import org.apache.helix.HelixAdmin; import org.apache.helix.model.IdealState; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.concurrent.ExecutorService; import java.util.concurrent.LinkedBlockingDeque; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; /** * Implementation of the terrapin controller thrift API. */ public class TerrapinControllerServiceImpl implements TerrapinController.ServiceIface { private static final Logger LOG = LoggerFactory.getLogger(TerrapinControllerServiceImpl.class); private final PropertiesConfiguration configuration; private final ZooKeeperManager zkManager; private final DFSClient hdfsClient; private final HelixAdmin helixAdmin; private final String clusterName; private final FuturePool futurePool; public TerrapinControllerServiceImpl(PropertiesConfiguration configuration, ZooKeeperManager zkManager, DFSClient hdfsClient, HelixAdmin helixAdmin, String clusterName) { this.configuration = configuration; this.zkManager = zkManager; this.hdfsClient = hdfsClient; this.helixAdmin = helixAdmin; this.clusterName = clusterName; ExecutorService threadPool = new ThreadPoolExecutor(100, 100, 0, TimeUnit.SECONDS, new LinkedBlockingDeque<Runnable>(1000), new ThreadFactoryBuilder().setDaemon(false).setNameFormat("controller-pool-%d").build()); this.futurePool = new ExecutorServiceFuturePool(threadPool); } private static Exception getException(Exception e) { if (e instanceof ControllerException) { return e; } else { return new ControllerException(e.toString(), ControllerErrorCode.OTHER); } } @Override public Future<Void> loadFileSet(final TerrapinLoadRequest request) { return futurePool.apply(new ExceptionalFunction0<Void>() { @Override public Void applyE() throws Throwable { try { String hdfsDir = request.getHdfsDirectory(); LOG.info("Loading resource " + hdfsDir); long startTimeMillis = System.currentTimeMillis(); String resourceName = TerrapinUtil.hdfsDirToHelixResource(hdfsDir); FileSetInfo oldFileSetInfo = zkManager.getFileSetInfo(request.getFileSet()); boolean resourceExists = helixAdmin.getResourcesInCluster(clusterName).contains(resourceName); if (oldFileSetInfo != null && oldFileSetInfo.servingInfo.hdfsPath.equals(hdfsDir) && resourceExists) { LOG.info("Resource and fileset already exist. Not doing anything."); return null; } // If we have already have a resource created, do not recreate the resource. Getting // all the resources is the only way to check the existence of a resource, this // will need optimization in the future once we have many resources. IdealState idealState = ControllerUtil.buildIdealStateForHdfsDir(hdfsClient, hdfsDir, resourceName, request.getOptions().getPartitioner(), configuration.getInt(Constants.NUM_SERVING_REPLICAS, 3), configuration.getBoolean( Constants.ENABLE_ZK_COMPRESSION, Constants.ENABLE_ZK_COMPRESSION_DEFAULT)); if (idealState.getNumPartitions() != request.getExpectedNumPartitions()) { throw new ControllerException("Partition count mismatch for hdfs dir " + hdfsDir + " FOUND : " + idealState.getNumPartitions() + " EXPECTED : " + request.getExpectedNumPartitions(), ControllerErrorCode.INVALID_DATA_SET); } try { if (idealState.getBucketSize() > 1) { if (!resourceExists) { // Add the resource without the ideal state - thats the only way to make buckets // work with the addResource call. helixAdmin.addResource(clusterName, resourceName, idealState.getNumPartitions(), "OnlineOffline", "CUSTOMIZED", idealState.getBucketSize()); } helixAdmin.setResourceIdealState(clusterName, resourceName, idealState); } else { if (!resourceExists) { helixAdmin.addResource(clusterName, resourceName, idealState); } else { helixAdmin.setResourceIdealState(clusterName, resourceName, idealState); } } } catch (Exception e) { LOG.warn("Resource creation failed for " + resourceName + ", rolling back.", e); throw new ControllerException("Resource creation failure for " + resourceName, ControllerErrorCode.HELIX_ERROR); } LOG.info("Time taken for building resource for " + hdfsDir + ": " + (System.currentTimeMillis() - startTimeMillis) + "ms."); LOG.info("New resource " + resourceName); // Wait for loading of the resource. long startLoadTimeMillis = System.currentTimeMillis(); boolean isLoaded = false; while (!isLoaded) { long timeElapsedMillis = System.currentTimeMillis() - startLoadTimeMillis; if (timeElapsedMillis > Constants.LOAD_TIMEOUT_SECONDS * 1000) { throw new ControllerException("Timeout while trying to online resource " + resourceName, ControllerErrorCode.SHARD_LOAD_TIMEOUT); } Thread.sleep(5000); timeElapsedMillis = System.currentTimeMillis() - startLoadTimeMillis; ViewInfo viewInfo = zkManager.getViewInfo(resourceName); if (viewInfo == null) { continue; } int numLoaded = viewInfo.getNumOnlinePartitions(); if (numLoaded == idealState.getNumPartitions()) { LOG.info("Onlined " + resourceName + " in " + timeElapsedMillis + "ms."); isLoaded = true; } else { LOG.info("Onlined " + numLoaded + "/" + idealState.getNumPartitions() + " partitions for resource " + resourceName + " in " + timeElapsedMillis + "ms."); } } // Wait for a couple of seconds just for the zk watches to propagate. Thread.sleep(2000); List<FileSetInfo.ServingInfo> oldServingInfoList = null; if (oldFileSetInfo == null) { oldServingInfoList = Lists.newArrayList(); } else { // Drop the oldest path from the oldFileSetInfo. oldServingInfoList = oldFileSetInfo.oldServingInfoList; oldServingInfoList.add(0, oldFileSetInfo.servingInfo); while (oldServingInfoList.size() >= request.getOptions().getNumVersionsToKeep() && !oldServingInfoList.isEmpty()) { oldServingInfoList.remove(oldServingInfoList.size() - 1); } } FileSetInfo fileSetInfo = new FileSetInfo(request.getFileSet(), hdfsDir, idealState.getNumPartitions(), oldServingInfoList, request.getOptions()); zkManager.setFileSetInfo(request.getFileSet(), fileSetInfo); } catch (Exception e) { LOG.warn("Exception while loading.", e); throw getException(e); } return null; } }); } }