/*
*
* 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.replication;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.List;
import com.google.common.annotations.VisibleForTesting;
import org.apache.hadoop.hbase.shaded.com.google.protobuf.CodedOutputStream;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Abortable;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos;
import org.apache.hadoop.hbase.zookeeper.ZKConfig;
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.
*/
@InterfaceAudience.Private
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 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 name of the znode that contains queues of hfile references to be replicated */
protected final String hfileRefsZNode;
/** The cluster key of the local cluster */
protected final String ourClusterKey;
/** The name of the znode that contains tableCFs */
protected final String tableCFsNodeName;
protected final ZooKeeperWatcher zookeeper;
protected final Configuration conf;
protected final Abortable abortable;
// Public for testing
public static final byte[] ENABLED_ZNODE_BYTES =
toByteArray(ReplicationProtos.ReplicationState.State.ENABLED);
public static final byte[] DISABLED_ZNODE_BYTES =
toByteArray(ReplicationProtos.ReplicationState.State.DISABLED);
public static final String ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_KEY =
"zookeeper.znode.replication.hfile.refs";
public static final String ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_DEFAULT = "hfile-refs";
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 hfileRefsZNodeName = conf.get(ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_KEY,
ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_DEFAULT);
this.peerStateNodeName = conf.get("zookeeper.znode.replication.peers.state", "peer-state");
this.tableCFsNodeName = conf.get("zookeeper.znode.replication.peers.tableCFs", "tableCFs");
this.ourClusterKey = ZKConfig.getZooKeeperClusterKey(this.conf);
this.replicationZNode = ZKUtil.joinZNode(this.zookeeper.znodePaths.baseZNode,
replicationZNodeName);
this.peersZNode = ZKUtil.joinZNode(replicationZNode, peersZNodeName);
this.queuesZNode = ZKUtil.joinZNode(replicationZNode, queuesZNodeName);
this.hfileRefsZNode = ZKUtil.joinZNode(replicationZNode, hfileRefsZNodeName);
}
public List<String> getListOfReplicators() {
List<String> 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 <code>state</code> with pb magic prefix prepended suitable for
* use 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 ReplicationProtos.ReplicationState.State state) {
ReplicationProtos.ReplicationState msg =
ReplicationProtos.ReplicationState.newBuilder().setState(state).build();
// There is no toByteArray on this pb Message?
// 32 bytes is default which seems fair enough here.
try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
CodedOutputStream cos = CodedOutputStream.newInstance(baos, 16);
msg.writeTo(cos);
cos.flush();
baos.flush();
return ProtobufUtil.prependPBMagic(baos.toByteArray());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
protected boolean peerExists(String id) throws KeeperException {
return ZKUtil.checkExists(this.zookeeper, ZKUtil.joinZNode(this.peersZNode, id)) >= 0;
}
/**
* Determine if a ZK path points to a peer node.
* @param path path to be checked
* @return true if the path points to a peer node, otherwise false
*/
protected boolean isPeerPath(String path) {
return path.split("/").length == peersZNode.split("/").length + 1;
}
@VisibleForTesting
protected String getTableCFsNode(String id) {
return ZKUtil.joinZNode(this.peersZNode, ZKUtil.joinZNode(id, this.tableCFsNodeName));
}
@VisibleForTesting
protected String getPeerStateNode(String id) {
return ZKUtil.joinZNode(this.peersZNode, ZKUtil.joinZNode(id, this.peerStateNodeName));
}
@VisibleForTesting
protected String getPeerNode(String id) {
return ZKUtil.joinZNode(this.peersZNode, id);
}
}