src/main/java/com/att/dmf/mr/backends/kafka/KafkaLiveLockAvoider2.java

   1 /*******************************************************************************
   2  *  ============LICENSE_START=======================================================
   3  *  org.onap.dmaap
   4  *  ================================================================================
   5  *  Copyright © 2017 AT&T Intellectual Property. All rights reserved.
   6  *  ================================================================================
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *        http://www.apache.org/licenses/LICENSE-2.0
  11 *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  *  ============LICENSE_END=========================================================
  18  *
  19  *  ECOMP is a trademark and service mark of AT&T Intellectual Property.
  20  *
  21  *******************************************************************************/
  22 package com.att.dmf.mr.backends.kafka;
  23
  24
  25 import java.util.List;
  26 import java.util.concurrent.TimeUnit;
  27
  28 import javax.annotation.PostConstruct;
  29
  30 import org.apache.curator.framework.CuratorFramework;
  31 import org.apache.curator.framework.recipes.locks.InterProcessMutex;
  32 import org.apache.zookeeper.CreateMode;
  33 import org.apache.zookeeper.Watcher;
  34 import com.att.eelf.configuration.EELFLogger;
  35 import com.att.eelf.configuration.EELFManager;
  36 import org.springframework.beans.factory.annotation.Autowired;
  37 import org.springframework.beans.factory.annotation.Qualifier;
  38 import org.springframework.stereotype.Component;
  39
  40 //@ComponentScan(basePackages="com.att.dmf.mr.backends.kafka")
  41 @Component
  42 public class KafkaLiveLockAvoider2 {
  43
  44         public static final String ZNODE_ROOT = "/live-lock-avoid";
  45         public static final String ZNODE_LOCKS = "/locks";
  46         public static final String ZNODE_UNSTICK_TASKS ="/unstick-tasks";
  47
  48         private static String locksPath = ZNODE_ROOT+ZNODE_LOCKS;
  49         private static String tasksPath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS;
  50         private static final EELFLogger log = EELFManager.getInstance().getLogger(KafkaLiveLockAvoider2.class.getName());
  51
  52         @Autowired
  53         @Qualifier("curator")
  54         private CuratorFramework curatorFramework;
  55
  56    @PostConstruct
  57         public void init() {
  58          log.info("Welcome......................................................................................");
  59         try {
  60                 if (curatorFramework.checkExists().forPath(locksPath) == null) {
  61                         curatorFramework.create().creatingParentsIfNeeded().forPath(locksPath);
  62                 }
  63                 if (curatorFramework.checkExists().forPath(tasksPath) == null) {
  64                         curatorFramework.create().creatingParentsIfNeeded().forPath(tasksPath);
  65                 }
  66
  67         } catch (Exception e) {
  68
  69                 log.error("Error during creation of permanent Znodes under /live-lock-avoid ",e);
  70
  71         }
  72
  73
  74         }
  75         public void unlockConsumerGroup(String appId, String groupName) throws Exception {
  76
  77                 log.info("Signalling unlock to all conumsers of in group [{}] now, " ,  groupName);
  78
  79                 String fullLockPath = String.format("%s/%s", locksPath, groupName );
  80                 String fullTasksPath = null;
  81
  82                 try {
  83
  84                         //Use the Curator recipe for a Mutex lock, only one process can be broadcasting unlock instructions for a group
  85                         InterProcessMutex lock = new InterProcessMutex(curatorFramework, fullLockPath);
  86                         if ( lock.acquire(100L, TimeUnit.MILLISECONDS) )
  87                         {
  88                                 try
  89                                 {
  90                                         List<String> taskNodes = curatorFramework.getChildren().forPath(tasksPath);
  91                                         for (String taskNodeName : taskNodes) {
  92                                                 if(!taskNodeName.equals(appId)) {
  93
  94                                                         fullTasksPath = String.format("%s/%s/%s", tasksPath, taskNodeName, groupName);
  95                                                         log.info("Writing groupName {} to path {}",groupName, fullTasksPath);
  96
  97
  98                                                         if(curatorFramework.checkExists().forPath(fullTasksPath) != null) {
  99                                                                 curatorFramework.delete().forPath(fullTasksPath);
 100                                                         }
 101                                                         curatorFramework.create().withMode(CreateMode.EPHEMERAL).forPath(fullTasksPath);
 102                                                 }
 103                                         }
 104
 105
 106                                 }
 107                                 finally
 108                                 {
 109                                         //Curator lock recipe requires a acquire() to be followed by a release()
 110                                         lock.release();
 111                                 }
 112                         }else {
 113                                 log.info("Could not obtain the avoider lock, another process has the avoider lock? {}", !lock.isAcquiredInThisProcess() );
 114                         }
 115
 116
 117                 } catch (Exception e) {
 118                         log.error("Error setting up either lock ZNode {} or task  ZNode {}",fullLockPath, fullTasksPath,e);
 119                         throw e;
 120                 }
 121
 122
 123         }
 124
 125         /*
 126          * Shoud be called once per MR server instance.
 127          *
 128          */
 129         public void startNewWatcherForServer(String appId, LiveLockAvoidance avoidanceCallback) {
 130                 LockInstructionWatcher instructionWatcher = new LockInstructionWatcher(curatorFramework,avoidanceCallback,this);
 131                 assignNewProcessNode(appId, instructionWatcher);
 132
 133         }
 134
 135
 136         protected void assignNewProcessNode(String appId, Watcher processNodeWatcher ) {
 137
 138                 String taskHolderZnodePath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS+"/"+appId;
 139
 140
 141                 try {
 142
 143                         if(curatorFramework.checkExists().forPath(taskHolderZnodePath) != null) {
 144                                 curatorFramework.delete().deletingChildrenIfNeeded().forPath(taskHolderZnodePath);
 145
 146                         }
 147                         curatorFramework.create().forPath(taskHolderZnodePath);
 148                         //setup the watcher
 149                         curatorFramework.getChildren().usingWatcher(processNodeWatcher).inBackground().forPath(taskHolderZnodePath);
 150                         log.info("Done creating task holder and watcher for APP name: {}",appId);
 151
 152                 } catch (Exception e) {
 153                         log.error("Could not add new processing node for name {}", appId, e);
 154                 }
 155
 156         }
 157
 158
 159 }