/**
*
* 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.util;
import java.io.IOException;
import java.util.Collection;
import java.util.List;
import java.util.Random;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ClusterConnection;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.master.RegionState;
import org.apache.hadoop.hbase.master.ServerManager;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.zookeeper.KeeperException;
/**
* This class contains helper methods that repair parts of hbase's filesystem
* contents.
*/
@InterfaceAudience.Private
public class HBaseFsckRepair {
private static final Log LOG = LogFactory.getLog(HBaseFsckRepair.class);
/**
* Fix multiple assignment by doing silent closes on each RS hosting the region
* and then force ZK unassigned node to OFFLINE to trigger assignment by
* master.
*
* @param connection HBase connection to the cluster
* @param region Region to undeploy
* @param servers list of Servers to undeploy from
*/
public static void fixMultiAssignment(Connection connection, HRegionInfo region,
List<ServerName> servers)
throws IOException, KeeperException, InterruptedException {
HRegionInfo actualRegion = new HRegionInfo(region);
// Close region on the servers silently
for(ServerName server : servers) {
closeRegionSilentlyAndWait(connection, server, actualRegion);
}
// Force ZK node to OFFLINE so master assigns
forceOfflineInZK(connection.getAdmin(), actualRegion);
}
/**
* Fix unassigned by creating/transition the unassigned ZK node for this
* region to OFFLINE state with a special flag to tell the master that this is
* a forced operation by HBCK.
*
* This assumes that info is in META.
*
* @param admin
* @param region
* @throws IOException
* @throws KeeperException
*/
public static void fixUnassigned(Admin admin, HRegionInfo region)
throws IOException, KeeperException, InterruptedException {
HRegionInfo actualRegion = new HRegionInfo(region);
// Force ZK node to OFFLINE so master assigns
forceOfflineInZK(admin, actualRegion);
}
/**
* In 0.90, this forces an HRI offline by setting the RegionTransitionData
* in ZK to have HBCK_CODE_NAME as the server. This is a special case in
* the AssignmentManager that attempts an assign call by the master.
*
* @see org.apache.hadoop.hbase.master.AssignementManager#handleHBCK
*
* This doesn't seem to work properly in the updated version of 0.92+'s hbck
* so we use assign to force the region into transition. This has the
* side-effect of requiring a HRegionInfo that considers regionId (timestamp)
* in comparators that is addressed by HBASE-5563.
*/
private static void forceOfflineInZK(Admin admin, final HRegionInfo region)
throws ZooKeeperConnectionException, KeeperException, IOException, InterruptedException {
admin.assign(region.getRegionName());
}
/*
* Should we check all assignments or just not in RIT?
*/
public static void waitUntilAssigned(Admin admin,
HRegionInfo region) throws IOException, InterruptedException {
long timeout = admin.getConfiguration().getLong("hbase.hbck.assign.timeout", 120000);
long expiration = timeout + EnvironmentEdgeManager.currentTime();
while (EnvironmentEdgeManager.currentTime() < expiration) {
try {
boolean inTransition = false;
for (RegionState rs: admin.getClusterStatus().getRegionsInTransition()) {
if (rs.getRegion().equals(region)) {
inTransition = true;
break;
}
}
if (!inTransition) {
// yay! no longer RIT
return;
}
// still in rit
LOG.info("Region still in transition, waiting for "
+ "it to become assigned: " + region);
} catch (IOException e) {
LOG.warn("Exception when waiting for region to become assigned,"
+ " retrying", e);
}
Thread.sleep(1000);
}
throw new IOException("Region " + region + " failed to move out of " +
"transition within timeout " + timeout + "ms");
}
/**
* Contacts a region server and waits up to hbase.hbck.close.timeout ms
* (default 120s) to close the region. This bypasses the active hmaster.
*/
@SuppressWarnings("deprecation")
public static void closeRegionSilentlyAndWait(Connection connection,
ServerName server, HRegionInfo region) throws IOException, InterruptedException {
long timeout = connection.getConfiguration()
.getLong("hbase.hbck.close.timeout", 120000);
ServerManager.closeRegionSilentlyAndWait((ClusterConnection)connection, server,
region, timeout);
}
/**
* Puts the specified HRegionInfo into META with replica related columns
*/
public static void fixMetaHoleOnlineAndAddReplicas(Configuration conf,
HRegionInfo hri, Collection<ServerName> servers, int numReplicas) throws IOException {
Connection conn = ConnectionFactory.createConnection(conf);
Table meta = conn.getTable(TableName.META_TABLE_NAME);
Put put = MetaTableAccessor.makePutFromRegionInfo(hri);
if (numReplicas > 1) {
Random r = new Random();
ServerName[] serversArr = servers.toArray(new ServerName[servers.size()]);
for (int i = 1; i < numReplicas; i++) {
ServerName sn = serversArr[r.nextInt(serversArr.length)];
// the column added here is just to make sure the master is able to
// see the additional replicas when it is asked to assign. The
// final value of these columns will be different and will be updated
// by the actual regionservers that start hosting the respective replicas
MetaTableAccessor.addLocation(put, sn, sn.getStartcode(), -1, i);
}
}
meta.put(put);
meta.close();
conn.close();
}
/**
* Creates, flushes, and closes a new region.
*/
public static HRegion createHDFSRegionDir(Configuration conf,
HRegionInfo hri, HTableDescriptor htd) throws IOException {
// Create HRegion
Path root = FSUtils.getRootDir(conf);
HRegion region = HRegion.createHRegion(hri, root, conf, htd, null);
// Close the new region to flush to disk. Close log file too.
region.close();
return region;
}
/*
* Remove parent
*/
public static void removeParentInMeta(Configuration conf, HRegionInfo hri) throws IOException {
Connection conn = ConnectionFactory.createConnection(conf);
MetaTableAccessor.deleteRegion(conn, hri);
}
}