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/*******************************************************************************
* ============LICENSE_START=======================================================
* org.onap.dmaap
* ================================================================================
* Copyright © 2017 AT&T Intellectual Property. All rights reserved.
* ================================================================================
* Licensed 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.
* ============LICENSE_END=========================================================
*
* ECOMP is a trademark and service mark of AT&T Intellectual Property.
*
*******************************************************************************/
package org.onap.dmaap.dmf.mr.backends.kafka;
import java.util.List;
import java.util.concurrent.TimeUnit;
import javax.annotation.PostConstruct;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.Watcher;
import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
//@ComponentScan(basePackages="com.att.dmf.mr.backends.kafka")
@Component
public class KafkaLiveLockAvoider2 {
public static final String ZNODE_ROOT = "/live-lock-avoid";
public static final String ZNODE_LOCKS = "/locks";
public static final String ZNODE_UNSTICK_TASKS ="/unstick-tasks";
private static String locksPath = ZNODE_ROOT+ZNODE_LOCKS;
private static String tasksPath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS;
private static final EELFLogger log = EELFManager.getInstance().getLogger(KafkaLiveLockAvoider2.class.getName());
@Autowired
@Qualifier("curator")
private CuratorFramework curatorFramework;
@PostConstruct
public void init() {
log.info("Welcome......................................................................................");
try {
if (curatorFramework.checkExists().forPath(locksPath) == null) {
curatorFramework.create().creatingParentsIfNeeded().forPath(locksPath);
}
if (curatorFramework.checkExists().forPath(tasksPath) == null) {
curatorFramework.create().creatingParentsIfNeeded().forPath(tasksPath);
}
} catch (Exception e) {
log.error("Error during creation of permanent Znodes under /live-lock-avoid ",e);
}
}
public void unlockConsumerGroup(String appId, String groupName) throws Exception {
log.info("Signalling unlock to all conumsers of in group [{}] now, " , groupName);
String fullLockPath = String.format("%s/%s", locksPath, groupName );
String fullTasksPath = null;
try {
//Use the Curator recipe for a Mutex lock, only one process can be broadcasting unlock instructions for a group
InterProcessMutex lock = new InterProcessMutex(curatorFramework, fullLockPath);
if ( lock.acquire(100L, TimeUnit.MILLISECONDS) )
{
try
{
List<String> taskNodes = curatorFramework.getChildren().forPath(tasksPath);
for (String taskNodeName : taskNodes) {
if(!taskNodeName.equals(appId)) {
fullTasksPath = String.format("%s/%s/%s", tasksPath, taskNodeName, groupName);
log.info("Writing groupName {} to path {}",groupName, fullTasksPath);
if(curatorFramework.checkExists().forPath(fullTasksPath) != null) {
curatorFramework.delete().forPath(fullTasksPath);
}
curatorFramework.create().withMode(CreateMode.EPHEMERAL).forPath(fullTasksPath);
}
}
}
finally
{
//Curator lock recipe requires a acquire() to be followed by a release()
lock.release();
}
}else {
log.info("Could not obtain the avoider lock, another process has the avoider lock? {}", !lock.isAcquiredInThisProcess() );
}
} catch (Exception e) {
log.error("Error setting up either lock ZNode {} or task ZNode {}",fullLockPath, fullTasksPath,e);
throw e;
}
}
/*
* Shoud be called once per MR server instance.
*
*/
public void startNewWatcherForServer(String appId, LiveLockAvoidance avoidanceCallback) {
LockInstructionWatcher instructionWatcher = new LockInstructionWatcher(curatorFramework,avoidanceCallback,this);
assignNewProcessNode(appId, instructionWatcher);
}
protected void assignNewProcessNode(String appId, Watcher processNodeWatcher ) {
String taskHolderZnodePath = ZNODE_ROOT+ZNODE_UNSTICK_TASKS+"/"+appId;
try {
if(curatorFramework.checkExists().forPath(taskHolderZnodePath) != null) {
curatorFramework.delete().deletingChildrenIfNeeded().forPath(taskHolderZnodePath);
}
curatorFramework.create().forPath(taskHolderZnodePath);
//setup the watcher
curatorFramework.getChildren().usingWatcher(processNodeWatcher).inBackground().forPath(taskHolderZnodePath);
log.info("Done creating task holder and watcher for APP name: {}",appId);
} catch (Exception e) {
log.error("Could not add new processing node for name {}", appId, e);
}
}
}
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