/**
* 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.backup.example;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.master.cleaner.HFileCleaner;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.zookeeper.KeeperException;
/**
* Client-side manager for which table's hfiles should be preserved for long-term archive.
* @see ZKTableArchiveClient
* @see HFileArchiveTableMonitor
* @see LongTermArchivingHFileCleaner
*/
@InterfaceAudience.Private
class HFileArchiveManager {
private final String archiveZnode;
private static final Log LOG = LogFactory.getLog(HFileArchiveManager.class);
private final ZooKeeperWatcher zooKeeper;
private volatile boolean stopped = false;
public HFileArchiveManager(HConnection connection, Configuration conf)
throws ZooKeeperConnectionException, IOException {
this.zooKeeper = new ZooKeeperWatcher(conf, "hfileArchiveManager-on-" + connection.toString(),
connection);
this.archiveZnode = ZKTableArchiveClient.getArchiveZNode(this.zooKeeper.getConfiguration(),
this.zooKeeper);
}
/**
* Turn on auto-backups of HFiles on the specified table.
* <p>
* When HFiles would be deleted from the hfile archive, they are instead preserved.
* @param table name of the table for which to preserve hfiles.
* @return <tt>this</tt> for chaining.
* @throws KeeperException if we can't reach zookeeper to update the hfile cleaner.
*/
public HFileArchiveManager enableHFileBackup(byte[] table) throws KeeperException {
enable(this.zooKeeper, table);
return this;
}
/**
* Stop retaining HFiles for the given table in the archive. HFiles will be cleaned up on the next
* pass of the {@link HFileCleaner}, if the HFiles are retained by another cleaner.
* @param table name of the table for which to disable hfile retention.
* @return <tt>this</tt> for chaining.
* @throws KeeperException if if we can't reach zookeeper to update the hfile cleaner.
*/
public HFileArchiveManager disableHFileBackup(byte[] table) throws KeeperException {
disable(this.zooKeeper, table);
return this;
}
/**
* Disable long-term archival of all hfiles for all tables in the cluster.
* @return <tt>this</tt> for chaining.
* @throws IOException if the number of attempts is exceeded
*/
public HFileArchiveManager disableHFileBackup() throws IOException {
LOG.debug("Disabling backups on all tables.");
try {
ZKUtil.deleteNodeRecursively(this.zooKeeper, archiveZnode);
return this;
} catch (KeeperException e) {
throw new IOException("Unexpected ZK exception!", e);
}
}
/**
* Perform a best effort enable of hfile retention, which relies on zookeeper communicating the //
* * change back to the hfile cleaner.
* <p>
* No attempt is made to make sure that backups are successfully created - it is inherently an
* <b>asynchronous operation</b>.
* @param zooKeeper watcher connection to zk cluster
* @param table table name on which to enable archiving
* @throws KeeperException
*/
private void enable(ZooKeeperWatcher zooKeeper, byte[] table)
throws KeeperException {
LOG.debug("Ensuring archiving znode exists");
ZKUtil.createAndFailSilent(zooKeeper, archiveZnode);
// then add the table to the list of znodes to archive
String tableNode = this.getTableNode(table);
LOG.debug("Creating: " + tableNode + ", data: []");
ZKUtil.createSetData(zooKeeper, tableNode, new byte[0]);
}
/**
* Disable all archiving of files for a given table
* <p>
* Inherently an <b>asynchronous operation</b>.
* @param zooKeeper watcher for the ZK cluster
* @param table name of the table to disable
* @throws KeeperException if an unexpected ZK connection issues occurs
*/
private void disable(ZooKeeperWatcher zooKeeper, byte[] table) throws KeeperException {
// ensure the latest state of the archive node is found
zooKeeper.sync(archiveZnode);
// if the top-level archive node is gone, then we are done
if (ZKUtil.checkExists(zooKeeper, archiveZnode) < 0) {
return;
}
// delete the table node, from the archive
String tableNode = this.getTableNode(table);
// make sure the table is the latest version so the delete takes
zooKeeper.sync(tableNode);
LOG.debug("Attempting to delete table node:" + tableNode);
ZKUtil.deleteNodeRecursively(zooKeeper, tableNode);
}
public void stop() {
if (!this.stopped) {
this.stopped = true;
LOG.debug("Stopping HFileArchiveManager...");
this.zooKeeper.close();
}
}
/**
* Check to see if the table is currently marked for archiving
* @param table name of the table to check
* @return <tt>true</tt> if the archive znode for that table exists, <tt>false</tt> if not
* @throws KeeperException if an unexpected zookeeper error occurs
*/
public boolean isArchivingEnabled(byte[] table) throws KeeperException {
String tableNode = this.getTableNode(table);
return ZKUtil.checkExists(zooKeeper, tableNode) >= 0;
}
/**
* Get the zookeeper node associated with archiving the given table
* @param table name of the table to check
* @return znode for the table's archive status
*/
private String getTableNode(byte[] table) {
return ZKUtil.joinZNode(archiveZnode, Bytes.toString(table));
}
}