org.apache.hadoop.hbase.zookeeper.ZooKeeperHelper Maven / Gradle / Ivy
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* 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 org.apache.hadoop.hbase.zookeeper;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.util.Threads;
import org.apache.hbase.thirdparty.com.google.common.base.Stopwatch;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.zookeeper.ZooKeeper;
/**
* Methods that help working with ZooKeeper
*/
@InterfaceAudience.Private
public final class ZooKeeperHelper {
// This class cannot be instantiated
private ZooKeeperHelper() {
}
/**
* Get a ZooKeeper instance and wait until it connected before returning.
* @param sessionTimeoutMs Used as session timeout passed to the created ZooKeeper AND as the
* timeout to wait on connection establishment.
*/
public static ZooKeeper getConnectedZooKeeper(String connectString, int sessionTimeoutMs)
throws IOException {
ZooKeeper zookeeper = new ZooKeeper(connectString, sessionTimeoutMs, e -> {});
return ensureConnectedZooKeeper(zookeeper, sessionTimeoutMs);
}
/**
* Ensure passed zookeeper is connected.
* @param timeout Time to wait on established Connection
*/
public static ZooKeeper ensureConnectedZooKeeper(ZooKeeper zookeeper, int timeout)
throws ZooKeeperConnectionException {
if (zookeeper.getState().isConnected()) {
return zookeeper;
}
Stopwatch stopWatch = Stopwatch.createStarted();
// Make sure we are connected before we hand it back.
while(!zookeeper.getState().isConnected()) {
Threads.sleep(1);
if (stopWatch.elapsed(TimeUnit.MILLISECONDS) > timeout) {
throw new ZooKeeperConnectionException("Failed connect after waiting " +
stopWatch.elapsed(TimeUnit.MILLISECONDS) + "ms (zk session timeout); " +
zookeeper);
}
}
return zookeeper;
}
}