/**
* Copyright (C) 2012 LinkedIn Inc <opensource@linkedin.com>
*
* 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.
*/
package com.linkedin.helix.manager.zk;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.I0Itec.zkclient.DataUpdater;
import org.apache.log4j.Logger;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.data.Stat;
import com.linkedin.helix.ConfigScope.ConfigScopeProperty;
import com.linkedin.helix.PropertyPathConfig;
import com.linkedin.helix.PropertyType;
import com.linkedin.helix.ZNRecord;
public final class ZKUtil
{
private static Logger logger = Logger.getLogger(ZKUtil.class);
private static int RETRYLIMIT = 3;
private ZKUtil()
{
}
public static boolean isClusterSetup(String clusterName, ZkClient zkClient)
{
if (clusterName == null || zkClient == null)
{
return false;
}
boolean isValid =
zkClient.exists(PropertyPathConfig.getPath(PropertyType.IDEALSTATES, clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.CONFIGS,
clusterName,
ConfigScopeProperty.CLUSTER.toString(),
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.CONFIGS,
clusterName,
ConfigScopeProperty.PARTICIPANT.toString()))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.CONFIGS,
clusterName,
ConfigScopeProperty.RESOURCE.toString()))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.PROPERTYSTORE,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.LIVEINSTANCES,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.INSTANCES,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.EXTERNALVIEW,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.CONTROLLER,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.STATEMODELDEFS,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.MESSAGES_CONTROLLER,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.ERRORS_CONTROLLER,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.STATUSUPDATES_CONTROLLER,
clusterName))
&& zkClient.exists(PropertyPathConfig.getPath(PropertyType.HISTORY,
clusterName));
return isValid;
}
public static void createChildren(ZkClient client,
String parentPath,
List<ZNRecord> list)
{
client.createPersistent(parentPath, true);
if (list != null)
{
for (ZNRecord record : list)
{
createChildren(client, parentPath, record);
}
}
}
public static void createChildren(ZkClient client,
String parentPath,
ZNRecord nodeRecord)
{
client.createPersistent(parentPath, true);
String id = nodeRecord.getId();
String temp = parentPath + "/" + id;
client.createPersistent(temp, nodeRecord);
}
public static void dropChildren(ZkClient client, String parentPath, List<ZNRecord> list)
{
// TODO: check if parentPath exists
if (list != null)
{
for (ZNRecord record : list)
{
dropChildren(client, parentPath, record);
}
}
}
public static void dropChildren(ZkClient client, String parentPath, ZNRecord nodeRecord)
{
// TODO: check if parentPath exists
String id = nodeRecord.getId();
String temp = parentPath + "/" + id;
client.deleteRecursive(temp);
}
public static List<ZNRecord> getChildren(ZkClient client, String path)
{
// parent watch will be set by zkClient
List<String> children = client.getChildren(path);
if (children == null || children.size() == 0)
{
return Collections.emptyList();
}
List<ZNRecord> childRecords = new ArrayList<ZNRecord>();
for (String child : children)
{
String childPath = path + "/" + child;
Stat newStat = new Stat();
ZNRecord record = client.readDataAndStat(childPath, newStat, true);
if (record != null)
{
record.setVersion(newStat.getVersion());
record.setCreationTime(newStat.getCtime());
record.setModifiedTime(newStat.getMtime());
childRecords.add(record);
}
}
return childRecords;
}
public static void updateIfExists(ZkClient client,
String path,
final ZNRecord record,
boolean mergeOnUpdate)
{
if (client.exists(path))
{
DataUpdater<Object> updater = new DataUpdater<Object>()
{
@Override
public Object update(Object currentData)
{
return record;
}
};
client.updateDataSerialized(path, updater);
}
}
public static void createOrUpdate(ZkClient client,
String path,
final ZNRecord record,
final boolean persistent,
final boolean mergeOnUpdate)
{
int retryCount = 0;
while (retryCount < RETRYLIMIT)
{
try
{
if (client.exists(path))
{
DataUpdater<ZNRecord> updater = new DataUpdater<ZNRecord>()
{
@Override
public ZNRecord update(ZNRecord currentData)
{
if (currentData != null && mergeOnUpdate)
{
currentData.merge(record);
return currentData;
}
return record;
}
};
client.updateDataSerialized(path, updater);
}
else
{
CreateMode mode = (persistent) ? CreateMode.PERSISTENT : CreateMode.EPHEMERAL;
if (record.getDeltaList().size() > 0)
{
ZNRecord value = new ZNRecord(record.getId());
value.merge(record);
client.create(path, value, mode);
}
else
{
client.create(path, record, mode);
}
}
break;
}
catch (Exception e)
{
retryCount = retryCount + 1;
logger.warn("Exception trying to update " + path + " Exception:" + e.getMessage()
+ ". Will retry.");
}
}
}
public static void asyncCreateOrUpdate(ZkClient client,
String path,
final ZNRecord record,
final boolean persistent,
final boolean mergeOnUpdate)
{
try
{
if (client.exists(path))
{
if (mergeOnUpdate)
{
ZNRecord curRecord = client.readData(path);
if (curRecord != null)
{
curRecord.merge(record);
client.asyncSetData(path, curRecord, -1, null);
}
else
{
client.asyncSetData(path, record, -1, null);
}
}
else
{
client.asyncSetData(path, record, -1, null);
}
}
else
{
CreateMode mode = (persistent) ? CreateMode.PERSISTENT : CreateMode.EPHEMERAL;
if (record.getDeltaList().size() > 0)
{
ZNRecord newRecord = new ZNRecord(record.getId());
newRecord.merge(record);
client.create(path, null, mode);
client.asyncSetData(path, newRecord, -1, null);
}
else
{
client.create(path, null, mode);
client.asyncSetData(path, record, -1, null);
}
}
}
catch (Exception e)
{
logger.error("Exception in async create or update " + path + ". Exception: "
+ e.getMessage() + ". Give up.");
}
}
public static void createOrReplace(ZkClient client,
String path,
final ZNRecord record,
final boolean persistent)
{
int retryCount = 0;
while (retryCount < RETRYLIMIT)
{
try
{
if (client.exists(path))
{
DataUpdater<Object> updater = new DataUpdater<Object>()
{
@Override
public Object update(Object currentData)
{
return record;
}
};
client.updateDataSerialized(path, updater);
}
else
{
CreateMode mode = (persistent) ? CreateMode.PERSISTENT : CreateMode.EPHEMERAL;
client.create(path, record, mode);
}
break;
}
catch (Exception e)
{
retryCount = retryCount + 1;
logger.warn("Exception trying to createOrReplace " + path + " Exception:"
+ e.getMessage() + ". Will retry.");
}
}
}
public static void subtract(ZkClient client,
String path,
final ZNRecord recordTosubtract)
{
int retryCount = 0;
while (retryCount < RETRYLIMIT)
{
try
{
if (client.exists(path))
{
DataUpdater<ZNRecord> updater = new DataUpdater<ZNRecord>()
{
@Override
public ZNRecord update(ZNRecord currentData)
{
currentData.subtract(recordTosubtract);
return currentData;
}
};
client.updateDataSerialized(path, updater);
break;
}
}
catch (Exception e)
{
retryCount = retryCount + 1;
logger.warn("Exception trying to createOrReplace " + path + " Exception:"
+ e.getMessage() + ". Will retry.");
e.printStackTrace();
}
}
}
}