| /** |
| * 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.master; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.Abortable; |
| import org.apache.hadoop.hbase.zookeeper.ZKNodeTracker; |
| import org.apache.hadoop.hbase.zookeeper.ZKUtil; |
| import org.apache.hadoop.hbase.zookeeper.ZNodePaths; |
| import org.apache.hadoop.hbase.zookeeper.ZKWatcher; |
| import org.apache.hadoop.hbase.client.MasterSwitchType; |
| import org.apache.hadoop.hbase.exceptions.DeserializationException; |
| import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil; |
| import org.apache.hadoop.hbase.shaded.protobuf.generated.ZooKeeperProtos.SwitchState; |
| import org.apache.hadoop.hbase.util.Bytes; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.apache.zookeeper.KeeperException; |
| |
| |
| /** |
| * Tracks the switch of split and merge states in ZK |
| */ |
| @InterfaceAudience.Private |
| public class SplitOrMergeTracker { |
| |
| private String splitZnode; |
| private String mergeZnode; |
| |
| private SwitchStateTracker splitStateTracker; |
| private SwitchStateTracker mergeStateTracker; |
| |
| public SplitOrMergeTracker(ZKWatcher watcher, Configuration conf, |
| Abortable abortable) { |
| try { |
| if (ZKUtil.checkExists(watcher, watcher.getZNodePaths().switchZNode) < 0) { |
| ZKUtil.createAndFailSilent(watcher, watcher.getZNodePaths().switchZNode); |
| } |
| } catch (KeeperException e) { |
| throw new RuntimeException(e); |
| } |
| splitZnode = ZNodePaths.joinZNode(watcher.getZNodePaths().switchZNode, |
| conf.get("zookeeper.znode.switch.split", "split")); |
| mergeZnode = ZNodePaths.joinZNode(watcher.getZNodePaths().switchZNode, |
| conf.get("zookeeper.znode.switch.merge", "merge")); |
| splitStateTracker = new SwitchStateTracker(watcher, splitZnode, abortable); |
| mergeStateTracker = new SwitchStateTracker(watcher, mergeZnode, abortable); |
| } |
| |
| public void start() { |
| splitStateTracker.start(); |
| mergeStateTracker.start(); |
| } |
| |
| public boolean isSplitOrMergeEnabled(MasterSwitchType switchType) { |
| switch (switchType) { |
| case SPLIT: |
| return splitStateTracker.isSwitchEnabled(); |
| case MERGE: |
| return mergeStateTracker.isSwitchEnabled(); |
| default: |
| break; |
| } |
| return false; |
| } |
| |
| public void setSplitOrMergeEnabled(boolean enabled, MasterSwitchType switchType) |
| throws KeeperException { |
| switch (switchType) { |
| case SPLIT: |
| splitStateTracker.setSwitchEnabled(enabled); |
| break; |
| case MERGE: |
| mergeStateTracker.setSwitchEnabled(enabled); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| private static class SwitchStateTracker extends ZKNodeTracker { |
| |
| public SwitchStateTracker(ZKWatcher watcher, String node, Abortable abortable) { |
| super(watcher, node, abortable); |
| } |
| |
| /** |
| * Return true if the switch is on, false otherwise |
| */ |
| public boolean isSwitchEnabled() { |
| byte [] upData = super.getData(false); |
| try { |
| // if data in ZK is null, use default of on. |
| return upData == null || parseFrom(upData).getEnabled(); |
| } catch (DeserializationException dex) { |
| LOG.error("ZK state for LoadBalancer could not be parsed " + Bytes.toStringBinary(upData)); |
| // return false to be safe. |
| return false; |
| } |
| } |
| |
| /** |
| * Set the switch on/off |
| * @param enabled switch enabled or not? |
| * @throws KeeperException keepException will be thrown out |
| */ |
| public void setSwitchEnabled(boolean enabled) throws KeeperException { |
| byte [] upData = toByteArray(enabled); |
| try { |
| ZKUtil.setData(watcher, node, upData); |
| } catch(KeeperException.NoNodeException nne) { |
| ZKUtil.createAndWatch(watcher, node, upData); |
| } |
| super.nodeDataChanged(node); |
| } |
| |
| private byte [] toByteArray(boolean enabled) { |
| SwitchState.Builder builder = SwitchState.newBuilder(); |
| builder.setEnabled(enabled); |
| return ProtobufUtil.prependPBMagic(builder.build().toByteArray()); |
| } |
| |
| private SwitchState parseFrom(byte [] bytes) |
| throws DeserializationException { |
| ProtobufUtil.expectPBMagicPrefix(bytes); |
| SwitchState.Builder builder = SwitchState.newBuilder(); |
| try { |
| int magicLen = ProtobufUtil.lengthOfPBMagic(); |
| ProtobufUtil.mergeFrom(builder, bytes, magicLen, bytes.length - magicLen); |
| } catch (IOException e) { |
| throw new DeserializationException(e); |
| } |
| return builder.build(); |
| } |
| } |
| } |