/**
*
* 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.IOException;
import java.io.InterruptedIOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.CoordinatedStateException;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.backup.HFileArchiver;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.AssignmentManager;
import org.apache.hadoop.hbase.master.HMaster;
import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
import org.apache.hadoop.hbase.master.MasterFileSystem;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.RegionState.State;
import org.apache.hadoop.hbase.master.RegionStates;
import org.apache.hadoop.hbase.regionserver.HRegion;
@InterfaceAudience.Private
public class DeleteTableHandler extends TableEventHandler {
private static final Log LOG = LogFactory.getLog(DeleteTableHandler.class);
protected HTableDescriptor hTableDescriptor = null;
public DeleteTableHandler(TableName tableName, Server server,
final MasterServices masterServices) {
super(EventType.C_M_DELETE_TABLE, tableName, server, masterServices);
}
@Override
protected void prepareWithTableLock() throws IOException {
// The next call fails if no such table.
hTableDescriptor = getTableDescriptor();
}
protected void waitRegionInTransition(final List<HRegionInfo> regions)
throws IOException, CoordinatedStateException {
AssignmentManager am = this.masterServices.getAssignmentManager();
RegionStates states = am.getRegionStates();
long waitTime = server.getConfiguration().
getLong("hbase.master.wait.on.region", 5 * 60 * 1000);
for (HRegionInfo region : regions) {
long done = System.currentTimeMillis() + waitTime;
while (System.currentTimeMillis() < done) {
if (states.isRegionInState(region, State.FAILED_OPEN)) {
am.regionOffline(region);
}
if (!states.isRegionInTransition(region)) break;
try {
Thread.sleep(waitingTimeForEvents);
} catch (InterruptedException e) {
LOG.warn("Interrupted while sleeping");
throw (InterruptedIOException)new InterruptedIOException().initCause(e);
}
LOG.debug("Waiting on region to clear regions in transition; "
+ am.getRegionStates().getRegionTransitionState(region));
}
if (states.isRegionInTransition(region)) {
throw new IOException("Waited hbase.master.wait.on.region (" +
waitTime + "ms) for region to leave region " +
region.getRegionNameAsString() + " in transitions");
}
}
}
@Override
protected void handleTableOperation(List<HRegionInfo> regions)
throws IOException, CoordinatedStateException {
MasterCoprocessorHost cpHost = ((HMaster) this.server).getMasterCoprocessorHost();
if (cpHost != null) {
cpHost.preDeleteTableHandler(this.tableName);
}
// 1. Wait because of region in transition
waitRegionInTransition(regions);
try {
// 2. Remove table from hbase:meta and HDFS
removeTableData(regions);
} finally {
// 3. Update table descriptor cache
LOG.debug("Removing '" + tableName + "' descriptor.");
this.masterServices.getTableDescriptors().remove(tableName);
AssignmentManager am = this.masterServices.getAssignmentManager();
// 4. Clean up regions of the table in RegionStates.
LOG.debug("Removing '" + tableName + "' from region states.");
am.getRegionStates().tableDeleted(tableName);
// 5. If entry for this table in zk, and up in AssignmentManager, remove it.
LOG.debug("Marking '" + tableName + "' as deleted.");
am.getTableStateManager().setDeletedTable(tableName);
// 6.Clean any remaining rows for this table.
cleanAnyRemainingRows();
}
if (cpHost != null) {
cpHost.postDeleteTableHandler(this.tableName);
}
}
/**
* There may be items for this table still up in hbase:meta in the case where the
* info:regioninfo column was empty because of some write error. Remove ALL rows from hbase:meta
* that have to do with this table. See HBASE-12980.
* @throws IOException
*/
private void cleanAnyRemainingRows() throws IOException {
Scan tableScan = MetaTableAccessor.getScanForTableName(tableName);
try (Table metaTable =
this.masterServices.getConnection().getTable(TableName.META_TABLE_NAME)) {
List<Delete> deletes = new ArrayList<Delete>();
try (ResultScanner resScanner = metaTable.getScanner(tableScan)) {
for (Result result : resScanner) {
deletes.add(new Delete(result.getRow()));
}
}
if (!deletes.isEmpty()) {
LOG.warn("Deleting some vestigal " + deletes.size() + " rows of " + this.tableName +
" from " + TableName.META_TABLE_NAME);
metaTable.delete(deletes);
}
}
}
/**
* Removes the table from hbase:meta and archives the HDFS files.
*/
protected void removeTableData(final List<HRegionInfo> regions)
throws IOException, CoordinatedStateException {
// 1. Remove regions from META
LOG.debug("Deleting regions from META");
MetaTableAccessor.deleteRegions(this.server.getConnection(), regions);
// -----------------------------------------------------------------------
// NOTE: At this point we still have data on disk, but nothing in hbase:meta
// if the rename below fails, hbck will report an inconsistency.
// -----------------------------------------------------------------------
// 2. Move the table in /hbase/.tmp
MasterFileSystem mfs = this.masterServices.getMasterFileSystem();
Path tempTableDir = mfs.moveTableToTemp(tableName);
// 3. Archive regions from FS (temp directory)
FileSystem fs = mfs.getFileSystem();
for (HRegionInfo hri : regions) {
LOG.debug("Archiving region " + hri.getRegionNameAsString() + " from FS");
HFileArchiver.archiveRegion(fs, mfs.getRootDir(),
tempTableDir, HRegion.getRegionDir(tempTableDir, hri.getEncodedName()));
}
// 4. Delete table directory from FS (temp directory)
if (!fs.delete(tempTableDir, true)) {
LOG.error("Couldn't delete " + tempTableDir);
}
LOG.debug("Table '" + tableName + "' archived!");
}
@Override
protected void releaseTableLock() {
super.releaseTableLock();
try {
masterServices.getTableLockManager().tableDeleted(tableName);
} catch (IOException ex) {
LOG.warn("Received exception from TableLockManager.tableDeleted:", ex); //not critical
}
}
@Override
public String toString() {
String name = "UnknownServerName";
if(server != null && server.getServerName() != null) {
name = server.getServerName().toString();
}
return getClass().getSimpleName() + "-" + name + "-" + getSeqid() + "-" + tableName;
}
}