/**
*
* 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.master.handler;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.NavigableMap;
import java.util.TreeMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.CoordinatedStateException;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.InvalidFamilyOperationException;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.TableNotDisabledException;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.BulkReOpen;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.TableLockManager.TableLock;
import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
/**
* Base class for performing operations against tables.
* Checks on whether the process can go forward are done in constructor rather
* than later on in {@link #process()}. The idea is to fail fast rather than
* later down in an async invocation of {@link #process()} (which currently has
* no means of reporting back issues once started).
*/
@InterfaceAudience.Private
public abstract class TableEventHandler extends EventHandler {
private static final Log LOG = LogFactory.getLog(TableEventHandler.class);
protected final MasterServices masterServices;
protected final TableName tableName;
protected TableLock tableLock;
private boolean isPrepareCalled = false;
public TableEventHandler(EventType eventType, TableName tableName, Server server,
MasterServices masterServices) {
super(server, eventType);
this.masterServices = masterServices;
this.tableName = tableName;
}
public TableEventHandler prepare() throws IOException {
//acquire the table write lock, blocking
this.tableLock = masterServices.getTableLockManager()
.writeLock(tableName, eventType.toString());
this.tableLock.acquire();
boolean success = false;
try {
try {
this.masterServices.checkTableModifiable(tableName);
} catch (TableNotDisabledException ex) {
if (isOnlineSchemaChangeAllowed()
&& eventType.isOnlineSchemaChangeSupported()) {
LOG.debug("Ignoring table not disabled exception " +
"for supporting online schema changes.");
} else {
throw ex;
}
}
prepareWithTableLock();
success = true;
} finally {
if (!success ) {
releaseTableLock();
}
}
this.isPrepareCalled = true;
return this;
}
/** Called from prepare() while holding the table lock. Subclasses
* can do extra initialization, and not worry about the releasing
* the table lock. */
protected void prepareWithTableLock() throws IOException {
}
private boolean isOnlineSchemaChangeAllowed() {
return this.server.getConfiguration().getBoolean(
"hbase.online.schema.update.enable", false);
}
@Override
public void process() {
if (!isPrepareCalled) {
//For proper table locking semantics, the implementor should ensure to call
//TableEventHandler.prepare() before calling process()
throw new RuntimeException("Implementation should have called prepare() first");
}
try {
LOG.info("Handling table operation " + eventType + " on table " +
tableName);
List<HRegionInfo> hris;
if (TableName.META_TABLE_NAME.equals(tableName)) {
hris = new MetaTableLocator().getMetaRegions(server.getZooKeeper());
} else {
hris = MetaTableAccessor.getTableRegions(server.getZooKeeper(),
server.getConnection(), tableName);
}
handleTableOperation(hris);
if (eventType.isOnlineSchemaChangeSupported() && this.masterServices.
getAssignmentManager().getTableStateManager().isTableState(
tableName, ZooKeeperProtos.Table.State.ENABLED)) {
if (reOpenAllRegions(hris)) {
LOG.info("Completed table operation " + eventType + " on table " +
tableName);
} else {
LOG.warn("Error on reopening the regions");
}
}
completed(null);
} catch (IOException e) {
LOG.error("Error manipulating table " + tableName, e);
completed(e);
} catch (CoordinatedStateException e) {
LOG.error("Error manipulating table " + tableName, e);
completed(e);
} finally {
releaseTableLock();
}
}
protected void releaseTableLock() {
if (this.tableLock != null) {
try {
this.tableLock.release();
} catch (IOException ex) {
LOG.warn("Could not release the table lock", ex);
}
}
}
/**
* Called after that process() is completed.
* @param exception null if process() is successful or not null if something has failed.
*/
protected void completed(final Throwable exception) {
}
public boolean reOpenAllRegions(List<HRegionInfo> regions) throws IOException {
boolean done = false;
LOG.info("Bucketing regions by region server...");
List<HRegionLocation> regionLocations = null;
Connection connection = this.masterServices.getConnection();
try (RegionLocator locator = connection.getRegionLocator(tableName)) {
regionLocations = locator.getAllRegionLocations();
}
// Convert List<HRegionLocation> to Map<HRegionInfo, ServerName>.
NavigableMap<HRegionInfo, ServerName> hri2Sn = new TreeMap<HRegionInfo, ServerName>();
for (HRegionLocation location: regionLocations) {
hri2Sn.put(location.getRegionInfo(), location.getServerName());
}
TreeMap<ServerName, List<HRegionInfo>> serverToRegions = Maps.newTreeMap();
List<HRegionInfo> reRegions = new ArrayList<HRegionInfo>();
for (HRegionInfo hri : regions) {
ServerName sn = hri2Sn.get(hri);
// Skip the offlined split parent region
// See HBASE-4578 for more information.
if (null == sn) {
LOG.info("Skip " + hri);
continue;
}
if (!serverToRegions.containsKey(sn)) {
LinkedList<HRegionInfo> hriList = Lists.newLinkedList();
serverToRegions.put(sn, hriList);
}
reRegions.add(hri);
serverToRegions.get(sn).add(hri);
}
LOG.info("Reopening " + reRegions.size() + " regions on "
+ serverToRegions.size() + " region servers.");
this.masterServices.getAssignmentManager().setRegionsToReopen(reRegions);
BulkReOpen bulkReopen = new BulkReOpen(this.server, serverToRegions,
this.masterServices.getAssignmentManager());
while (true) {
try {
if (bulkReopen.bulkReOpen()) {
done = true;
break;
} else {
LOG.warn("Timeout before reopening all regions");
}
} catch (InterruptedException e) {
LOG.warn("Reopen was interrupted");
// Preserve the interrupt.
Thread.currentThread().interrupt();
break;
}
}
return done;
}
/**
* Gets a TableDescriptor from the masterServices. Can Throw exceptions.
*
* @return Table descriptor for this table
* @throws TableExistsException
* @throws FileNotFoundException
* @throws IOException
*/
public HTableDescriptor getTableDescriptor()
throws FileNotFoundException, IOException {
HTableDescriptor htd =
this.masterServices.getTableDescriptors().get(tableName);
if (htd == null) {
throw new IOException("HTableDescriptor missing for " + tableName);
}
return htd;
}
byte [] hasColumnFamily(final HTableDescriptor htd, final byte [] cf)
throws InvalidFamilyOperationException {
if (!htd.hasFamily(cf)) {
throw new InvalidFamilyOperationException("Column family '" +
Bytes.toString(cf) + "' does not exist");
}
return cf;
}
protected abstract void handleTableOperation(List<HRegionInfo> regions)
throws IOException, CoordinatedStateException;
}