src/main/java/org/onap/dmaap/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 org.onap.dmaap.dmf.mr.backends.kafka;
  23
  24
  25 import com.att.eelf.configuration.EELFLogger;
  26 import com.att.eelf.configuration.EELFManager;
  27 import org.apache.curator.framework.CuratorFramework;
  28 import org.apache.curator.framework.recipes.locks.InterProcessMutex;
  29 import org.apache.zookeeper.CreateMode;
  30 import org.apache.zookeeper.Watcher;
  31 import org.springframework.beans.factory.annotation.Autowired;
  32 import org.springframework.beans.factory.annotation.Qualifier;
  33 import org.springframework.stereotype.Component;
  34
  35 import javax.annotation.PostConstruct;
  36 import java.util.List;
  37 import java.util.concurrent.TimeUnit;
  38
  39 //@ComponentScan(basePackages="com.att.dmf.mr.backends.kafka")
  40 @Component
  41 public class KafkaLiveLockAvoider2 {
  42
  43         public static final String ZNODE_ROOT = "/live-lock-avoid";
  44         public static final String ZNODE_LOCKS = "/locks";
  45         public static final String ZNODE_UNSTICK_TASKS ="/unstick-tasks";
  46
  47         private static String locksPath = ZNODE_ROOT+ZNODE_LOCKS;
  48         private static String tasksPath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS;
  49         private static final EELFLogger log = EELFManager.getInstance().getLogger(KafkaLiveLockAvoider2.class.getName());
  50
  51         @Autowired
  52         @Qualifier("curator")
  53         private CuratorFramework curatorFramework;
  54
  55    @PostConstruct
  56         public void init() {
  57          log.info("Welcome......................................................................................");
  58         try {
  59                 if (curatorFramework.checkExists().forPath(locksPath) == null) {
  60                         curatorFramework.create().creatingParentsIfNeeded().forPath(locksPath);
  61                 }
  62                 if (curatorFramework.checkExists().forPath(tasksPath) == null) {
  63                         curatorFramework.create().creatingParentsIfNeeded().forPath(tasksPath);
  64                 }
  65
  66         } catch (Exception e) {
  67
  68                 log.error("Error during creation of permanent Znodes under /live-lock-avoid ",e);
  69
  70         }
  71
  72
  73         }
  74         public void unlockConsumerGroup(String appId, String groupName) throws Exception {
  75
  76                 log.info("Signalling unlock to all conumsers of in group [{}] now, " ,  groupName);
  77
  78                 String fullLockPath = String.format("%s/%s", locksPath, groupName );
  79                 String fullTasksPath = null;
  80
  81                 try {
  82
  83                         //Use the Curator recipe for a Mutex lock, only one process can be broadcasting unlock instructions for a group
  84                         InterProcessMutex lock = new InterProcessMutex(curatorFramework, fullLockPath);
  85                         if ( lock.acquire(100L, TimeUnit.MILLISECONDS) )
  86                         {
  87                                 try
  88                                 {
  89                                         List<String> taskNodes = curatorFramework.getChildren().forPath(tasksPath);
  90                                         for (String taskNodeName : taskNodes) {
  91                                                 if(!taskNodeName.equals(appId)) {
  92
  93                                                         fullTasksPath = String.format("%s/%s/%s", tasksPath, taskNodeName, groupName);
  94                                                         log.info("Writing groupName {} to path {}",groupName, fullTasksPath);
  95
  96
  97                                                         if(curatorFramework.checkExists().forPath(fullTasksPath) != null) {
  98                                                                 curatorFramework.delete().forPath(fullTasksPath);
  99                                                         }
 100                                                         curatorFramework.create().withMode(CreateMode.EPHEMERAL).forPath(fullTasksPath);
 101                                                 }
 102                                         }
 103
 104
 105                                 }
 106                                 finally
 107                                 {
 108                                         //Curator lock recipe requires a acquire() to be followed by a release()
 109                                         lock.release();
 110                                 }
 111                         }else {
 112                                 log.info("Could not obtain the avoider lock, another process has the avoider lock? {}", !lock.isAcquiredInThisProcess() );
 113                         }
 114
 115
 116                 } catch (Exception e) {
 117                         log.error("Error setting up either lock ZNode {} or task  ZNode {}",fullLockPath, fullTasksPath,e);
 118                         throw e;
 119                 }
 120
 121
 122         }
 123
 124         /*
 125          * Shoud be called once per MR server instance.
 126          *
 127          */
 128         public void startNewWatcherForServer(String appId, LiveLockAvoidance avoidanceCallback) {
 129                 LockInstructionWatcher instructionWatcher = new LockInstructionWatcher(curatorFramework,avoidanceCallback,this);
 130                 assignNewProcessNode(appId, instructionWatcher);
 131
 132         }
 133
 134
 135         protected void assignNewProcessNode(String appId, Watcher processNodeWatcher ) {
 136
 137                 String taskHolderZnodePath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS+"/"+appId;
 138
 139
 140                 try {
 141
 142                         if(curatorFramework.checkExists().forPath(taskHolderZnodePath) != null) {
 143                                 curatorFramework.delete().deletingChildrenIfNeeded().forPath(taskHolderZnodePath);
 144
 145                         }
 146                         curatorFramework.create().forPath(taskHolderZnodePath);
 147                         //setup the watcher
 148                         curatorFramework.getChildren().usingWatcher(processNodeWatcher).inBackground().forPath(taskHolderZnodePath);
 149                         log.info("Done creating task holder and watcher for APP name: {}",appId);
 150
 151                 } catch (Exception e) {
 152                         log.error("Could not add new processing node for name {}", appId, e);
 153                 }
 154
 155         }
 156
 157
 158 }