001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.quotas;
019
020import java.io.IOException;
021
022import org.apache.hadoop.conf.Configuration;
023import org.apache.hadoop.hbase.util.Bytes;
024import org.apache.hadoop.hbase.zookeeper.ZKUtil;
025import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
026import org.apache.hadoop.hbase.zookeeper.ZNodePaths;
027import org.apache.yetus.audience.InterfaceAudience;
028import org.apache.zookeeper.KeeperException;
029
030/**
031 * ZK based rpc throttle storage.
032 */
033@InterfaceAudience.Private
034public class RpcThrottleStorage {
035  public static final String RPC_THROTTLE_ZNODE = "zookeeper.znode.quota.rpc.throttle";
036  public static final String RPC_THROTTLE_ZNODE_DEFAULT = "rpc-throttle";
037
038  private final ZKWatcher zookeeper;
039  private final String rpcThrottleZNode;
040
041  public RpcThrottleStorage(ZKWatcher zookeeper, Configuration conf) {
042    this.zookeeper = zookeeper;
043    this.rpcThrottleZNode = ZNodePaths.joinZNode(zookeeper.getZNodePaths().baseZNode,
044      conf.get(RPC_THROTTLE_ZNODE, RPC_THROTTLE_ZNODE_DEFAULT));
045  }
046
047  public boolean isRpcThrottleEnabled() throws IOException {
048    try {
049      byte[] upData = ZKUtil.getData(zookeeper, rpcThrottleZNode);
050      return upData == null || Bytes.toBoolean(upData);
051    } catch (KeeperException | InterruptedException e) {
052      throw new IOException("Failed to get rpc throttle", e);
053    }
054  }
055
056  /**
057   * Store the rpc throttle value.
058   * @param enable Set to <code>true</code> to enable, <code>false</code> to disable.
059   * @throws IOException if an unexpected io exception occurs
060   */
061  public void switchRpcThrottle(boolean enable) throws IOException {
062    try {
063      byte[] upData = Bytes.toBytes(enable);
064      ZKUtil.createSetData(zookeeper, rpcThrottleZNode, upData);
065    } catch (KeeperException e) {
066      throw new IOException("Failed to store rpc throttle", e);
067    }
068  }
069}