/**
* 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 com.twitter.distributedlog;
import com.google.common.base.Preconditions;
import com.twitter.distributedlog.ZooKeeperClient.Credentials;
import com.twitter.distributedlog.ZooKeeperClient.DigestCredentials;
import com.twitter.distributedlog.util.DLUtils;
import org.apache.bookkeeper.stats.NullStatsLogger;
import org.apache.bookkeeper.stats.StatsLogger;
import org.apache.bookkeeper.zookeeper.RetryPolicy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.net.URI;
/**
* Builder to build zookeeper client.
*/
public class ZooKeeperClientBuilder {
static final Logger LOG = LoggerFactory.getLogger(ZooKeeperClientBuilder.class);
/**
* Create a zookeeper client builder to build zookeeper clients.
*
* @return zookeeper client builder.
*/
public static ZooKeeperClientBuilder newBuilder() {
return new ZooKeeperClientBuilder();
}
// name
private String name = "default";
// sessionTimeoutMs
private int sessionTimeoutMs = -1;
// conectionTimeoutMs
private int conectionTimeoutMs = -1;
// zkServers
private String zkServers = null;
// retry policy
private RetryPolicy retryPolicy = null;
// stats logger
private StatsLogger statsLogger = NullStatsLogger.INSTANCE;
// retry executor thread count
private int retryThreadCount = 1;
// zookeeper access requestRateLimit limit
private double requestRateLimit = 0;
// Did call the zkAclId setter on the builder, used to ensure the setter is set.
private boolean zkAclIdSet = false;
private String zkAclId;
// Cached ZooKeeper Client
private ZooKeeperClient cachedClient = null;
private ZooKeeperClientBuilder() {}
/**
* Set zookeeper client name
*
* @param name zookeeper client name
* @return zookeeper client builder
*/
public synchronized ZooKeeperClientBuilder name(String name) {
this.name = name;
return this;
}
/**
* Set zookeeper session timeout in milliseconds.
*
* @param sessionTimeoutMs
* session timeout in milliseconds.
* @return zookeeper client builder.
*/
public synchronized ZooKeeperClientBuilder sessionTimeoutMs(int sessionTimeoutMs) {
this.sessionTimeoutMs = sessionTimeoutMs;
if (this.conectionTimeoutMs <= 0) {
this.conectionTimeoutMs = 2 * sessionTimeoutMs;
}
return this;
}
public synchronized ZooKeeperClientBuilder retryThreadCount(int retryThreadCount) {
this.retryThreadCount = retryThreadCount;
return this;
}
public synchronized ZooKeeperClientBuilder requestRateLimit(double requestRateLimit) {
this.requestRateLimit = requestRateLimit;
return this;
}
/**
* Set zookeeper connection timeout in milliseconds
*
* @param connectionTimeoutMs
* connection timeout ms.
* @return builder
*/
public synchronized ZooKeeperClientBuilder connectionTimeoutMs(int connectionTimeoutMs) {
this.conectionTimeoutMs = connectionTimeoutMs;
return this;
}
/**
* Set ZooKeeper Connect String.
*
* @param zkServers
* zookeeper servers to connect.
* @return builder
*/
public synchronized ZooKeeperClientBuilder zkServers(String zkServers) {
this.zkServers = zkServers;
return this;
}
/**
* Set DistributedLog URI.
*
* @param uri
* distributedlog uri.
* @return builder.
*/
public synchronized ZooKeeperClientBuilder uri(URI uri) {
this.zkServers = DLUtils.getZKServersFromDLUri(uri);
return this;
}
/**
* Build zookeeper client using existing <i>zkc</i> client.
*
* @param zkc
* zookeeper client.
* @return builder
*/
public synchronized ZooKeeperClientBuilder zkc(ZooKeeperClient zkc) {
this.cachedClient = zkc;
return this;
}
/**
* Build zookeeper client with given retry policy <i>retryPolicy</i>.
*
* @param retryPolicy
* retry policy
* @return builder
*/
public synchronized ZooKeeperClientBuilder retryPolicy(RetryPolicy retryPolicy) {
this.retryPolicy = retryPolicy;
return this;
}
/**
* Build zookeeper client with given stats logger <i>statsLogger</i>.
*
* @param statsLogger
* stats logger to expose zookeeper stats
* @return builder
*/
public synchronized ZooKeeperClientBuilder statsLogger(StatsLogger statsLogger) {
this.statsLogger = statsLogger;
return this;
}
/**
* * Build zookeeper client with given zk acl digest id <i>zkAclId</i>.
*/
public synchronized ZooKeeperClientBuilder zkAclId(String zkAclId) {
this.zkAclIdSet = true;
this.zkAclId = zkAclId;
return this;
}
private void validateParameters() {
Preconditions.checkNotNull(zkServers, "No zk servers provided.");
Preconditions.checkArgument(conectionTimeoutMs > 0,
"Invalid connection timeout : %d", conectionTimeoutMs);
Preconditions.checkArgument(sessionTimeoutMs > 0,
"Invalid session timeout : %d", sessionTimeoutMs);
Preconditions.checkNotNull(statsLogger, "No stats logger provided.");
Preconditions.checkArgument(zkAclIdSet, "Zookeeper acl id not set.");
}
/**
* Build a zookeeper client.
*
* @return zookeeper client.
*/
public synchronized ZooKeeperClient build() {
if (null == cachedClient) {
cachedClient = buildClient();
}
return cachedClient;
}
private ZooKeeperClient buildClient() {
validateParameters();
Credentials credentials = Credentials.NONE;
if (null != zkAclId) {
credentials = new DigestCredentials(zkAclId, zkAclId);
}
return new ZooKeeperClient(
name,
sessionTimeoutMs,
conectionTimeoutMs,
zkServers,
retryPolicy,
statsLogger,
retryThreadCount,
requestRateLimit,
credentials
);
}
}