/**
* 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;
import com.google.common.collect.Sets;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperListener;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.zookeeper.KeeperException;
import java.io.IOException;
import java.util.List;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.concurrent.ConcurrentSkipListMap;
/**
* Class servers two purposes:
*
* 1. Broadcast NamespaceDescriptor information via ZK
* (Done by the Master)
* 2. Consume broadcasted NamespaceDescriptor changes
* (Done by the RegionServers)
*
*/
@InterfaceAudience.Private
public class ZKNamespaceManager extends ZooKeeperListener {
private static final Log LOG = LogFactory.getLog(ZKNamespaceManager.class);
private final String nsZNode;
private volatile NavigableMap<String,NamespaceDescriptor> cache;
public ZKNamespaceManager(ZooKeeperWatcher zkw) throws IOException {
super(zkw);
nsZNode = zkw.znodePaths.namespaceZNode;
cache = new ConcurrentSkipListMap<>();
}
public void start() throws IOException {
watcher.registerListener(this);
try {
if (ZKUtil.watchAndCheckExists(watcher, nsZNode)) {
List<ZKUtil.NodeAndData> existing =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, nsZNode);
if (existing != null) {
refreshNodes(existing);
}
} else {
ZKUtil.createWithParents(watcher, nsZNode);
}
} catch (KeeperException e) {
throw new IOException("Failed to initialize ZKNamespaceManager", e);
}
}
public NamespaceDescriptor get(String name) {
return cache.get(name);
}
public void update(NamespaceDescriptor ns) throws IOException {
writeNamespace(ns);
cache.put(ns.getName(), ns);
}
public void remove(String name) throws IOException {
deleteNamespace(name);
cache.remove(name);
}
public NavigableSet<NamespaceDescriptor> list() throws IOException {
NavigableSet<NamespaceDescriptor> ret =
Sets.newTreeSet(NamespaceDescriptor.NAMESPACE_DESCRIPTOR_COMPARATOR);
for(NamespaceDescriptor ns: cache.values()) {
ret.add(ns);
}
return ret;
}
@Override
public void nodeCreated(String path) {
if (nsZNode.equals(path)) {
try {
List<ZKUtil.NodeAndData> nodes =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, nsZNode);
refreshNodes(nodes);
} catch (KeeperException ke) {
String msg = "Error reading data from zookeeper";
LOG.error(msg, ke);
watcher.abort(msg, ke);
} catch (IOException e) {
String msg = "Error parsing data from zookeeper";
LOG.error(msg, e);
watcher.abort(msg, e);
}
}
}
@Override
public void nodeDeleted(String path) {
if (nsZNode.equals(ZKUtil.getParent(path))) {
String nsName = ZKUtil.getNodeName(path);
cache.remove(nsName);
}
}
@Override
public void nodeDataChanged(String path) {
if (nsZNode.equals(ZKUtil.getParent(path))) {
try {
byte[] data = ZKUtil.getDataAndWatch(watcher, path);
NamespaceDescriptor ns =
ProtobufUtil.toNamespaceDescriptor(
HBaseProtos.NamespaceDescriptor.parseFrom(data));
cache.put(ns.getName(), ns);
} catch (KeeperException ke) {
String msg = "Error reading data from zookeeper for node "+path;
LOG.error(msg, ke);
// only option is to abort
watcher.abort(msg, ke);
} catch (IOException ioe) {
String msg = "Error deserializing namespace: "+path;
LOG.error(msg, ioe);
watcher.abort(msg, ioe);
}
}
}
@Override
public void nodeChildrenChanged(String path) {
if (nsZNode.equals(path)) {
try {
List<ZKUtil.NodeAndData> nodes =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, nsZNode);
refreshNodes(nodes);
} catch (KeeperException ke) {
LOG.error("Error reading data from zookeeper for path "+path, ke);
watcher.abort("ZooKeeper error get node children for path "+path, ke);
} catch (IOException e) {
LOG.error("Error deserializing namespace child from: "+path, e);
watcher.abort("Error deserializing namespace child from: " + path, e);
}
}
}
private void deleteNamespace(String name) throws IOException {
String zNode = ZKUtil.joinZNode(nsZNode, name);
try {
ZKUtil.deleteNode(watcher, zNode);
} catch (KeeperException e) {
if (e instanceof KeeperException.NoNodeException) {
// If the node does not exist, it could be already deleted. Continue without fail.
LOG.warn("The ZNode " + zNode + " for namespace " + name + " does not exist.");
} else {
LOG.error("Failed updating permissions for namespace " + name, e);
throw new IOException("Failed updating permissions for namespace " + name, e);
}
}
}
private void writeNamespace(NamespaceDescriptor ns) throws IOException {
String zNode = ZKUtil.joinZNode(nsZNode, ns.getName());
try {
ZKUtil.createWithParents(watcher, zNode);
ZKUtil.updateExistingNodeData(watcher, zNode,
ProtobufUtil.toProtoNamespaceDescriptor(ns).toByteArray(), -1);
} catch (KeeperException e) {
LOG.error("Failed updating permissions for namespace "+ns.getName(), e);
throw new IOException("Failed updating permissions for namespace "+ns.getName(), e);
}
}
private void refreshNodes(List<ZKUtil.NodeAndData> nodes) throws IOException {
for (ZKUtil.NodeAndData n : nodes) {
if (n.isEmpty()) continue;
String path = n.getNode();
String namespace = ZKUtil.getNodeName(path);
byte[] nodeData = n.getData();
if (LOG.isDebugEnabled()) {
LOG.debug("Updating namespace cache from node "+namespace+" with data: "+
Bytes.toStringBinary(nodeData));
}
NamespaceDescriptor ns =
ProtobufUtil.toNamespaceDescriptor(
HBaseProtos.NamespaceDescriptor.parseFrom(nodeData));
cache.put(ns.getName(), ns);
}
}
}