org.apache.hadoop.hbase.replication.ReplicationStateZKBase Maven / Gradle / Ivy
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*
* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.hadoop.hbase.replication;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Abortable;
import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.zookeeper.KeeperException;
/**
* This is a base class for maintaining replication state in zookeeper.
*/
public abstract class ReplicationStateZKBase {
/**
* The name of the znode that contains the replication status of a remote slave (i.e. peer)
* cluster.
*/
protected final String peerStateNodeName;
/** The name of the znode that contains the replication status of the local cluster. */
protected final String stateZNode;
/** The name of the base znode that contains all replication state. */
protected final String replicationZNode;
/** The name of the znode that contains a list of all remote slave (i.e. peer) clusters. */
protected final String peersZNode;
/** The name of the znode that contains all replication queues */
protected final String queuesZNode;
/** The cluster key of the local cluster */
protected final String ourClusterKey;
protected final ZooKeeperWatcher zookeeper;
protected final Configuration conf;
protected final Abortable abortable;
// Public for testing
public static final byte[] ENABLED_ZNODE_BYTES =
toByteArray(ZooKeeperProtos.ReplicationState.State.ENABLED);
protected static final byte[] DISABLED_ZNODE_BYTES =
toByteArray(ZooKeeperProtos.ReplicationState.State.DISABLED);
public ReplicationStateZKBase(ZooKeeperWatcher zookeeper, Configuration conf,
Abortable abortable) {
this.zookeeper = zookeeper;
this.conf = conf;
this.abortable = abortable;
String replicationZNodeName = conf.get("zookeeper.znode.replication", "replication");
String peersZNodeName = conf.get("zookeeper.znode.replication.peers", "peers");
String queuesZNodeName = conf.get("zookeeper.znode.replication.rs", "rs");
String stateZNodeName = conf.get("zookeeper.znode.replication.state", "state");
this.peerStateNodeName = conf.get("zookeeper.znode.replication.peers.state", "peer-state");
this.ourClusterKey = ZKUtil.getZooKeeperClusterKey(this.conf);
this.replicationZNode = ZKUtil.joinZNode(this.zookeeper.baseZNode, replicationZNodeName);
this.stateZNode = ZKUtil.joinZNode(replicationZNode, stateZNodeName);
this.peersZNode = ZKUtil.joinZNode(replicationZNode, peersZNodeName);
this.queuesZNode = ZKUtil.joinZNode(replicationZNode, queuesZNodeName);
}
public List getListOfReplicators() {
List result = null;
try {
result = ZKUtil.listChildrenNoWatch(this.zookeeper, this.queuesZNode);
} catch (KeeperException e) {
this.abortable.abort("Failed to get list of replicators", e);
}
return result;
}
/**
* @param state
* @return Serialized protobuf of state with pb magic prefix prepended suitable for
* use as content of either the cluster state znode -- whether or not we should be
* replicating kept in /hbase/replication/state -- or as content of a peer-state znode
* under a peer cluster id as in /hbase/replication/peers/PEER_ID/peer-state.
*/
protected static byte[] toByteArray(final ZooKeeperProtos.ReplicationState.State state) {
byte[] bytes =
ZooKeeperProtos.ReplicationState.newBuilder().setState(state).build().toByteArray();
return ProtobufUtil.prependPBMagic(bytes);
}
public boolean peerExists(String id) throws KeeperException {
return ZKUtil.checkExists(this.zookeeper, ZKUtil.joinZNode(this.peersZNode, id)) >= 0;
}
}