/**
*
* 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.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableNotDisabledException;
import org.apache.hadoop.hbase.TableNotFoundException;
import org.apache.hadoop.hbase.catalog.CatalogTracker;
import org.apache.hadoop.hbase.catalog.MetaReader;
import org.apache.hadoop.hbase.executor.EventHandler;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.AssignmentManager;
import org.apache.hadoop.hbase.master.BulkAssigner;
import org.apache.hadoop.hbase.master.HMaster;
import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
import org.apache.hadoop.hbase.master.RegionPlan;
import org.apache.hadoop.hbase.master.RegionStates;
import org.apache.hadoop.hbase.master.ServerManager;
import org.apache.hadoop.hbase.master.TableLockManager;
import org.apache.hadoop.hbase.master.TableLockManager.TableLock;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.zookeeper.KeeperException;
import org.cloudera.htrace.Trace;
/**
* Handler to run enable of a table.
*/
@InterfaceAudience.Private
public class EnableTableHandler extends EventHandler {
private static final Log LOG = LogFactory.getLog(EnableTableHandler.class);
private final TableName tableName;
private final AssignmentManager assignmentManager;
private final TableLockManager tableLockManager;
private final CatalogTracker catalogTracker;
private boolean skipTableStateCheck = false;
private TableLock tableLock;
public EnableTableHandler(Server server, TableName tableName,
CatalogTracker catalogTracker, AssignmentManager assignmentManager,
TableLockManager tableLockManager, boolean skipTableStateCheck) {
super(server, EventType.C_M_ENABLE_TABLE);
this.tableName = tableName;
this.catalogTracker = catalogTracker;
this.assignmentManager = assignmentManager;
this.tableLockManager = tableLockManager;
this.skipTableStateCheck = skipTableStateCheck;
}
public EnableTableHandler prepare()
throws TableNotFoundException, TableNotDisabledException, IOException {
//acquire the table write lock, blocking
this.tableLock = this.tableLockManager.writeLock(tableName,
EventType.C_M_ENABLE_TABLE.toString());
this.tableLock.acquire();
boolean success = false;
try {
// Check if table exists
if (!MetaReader.tableExists(catalogTracker, tableName)) {
// retainAssignment is true only during recovery. In normal case it is false
if (!this.skipTableStateCheck) {
throw new TableNotFoundException(tableName);
}
try {
this.assignmentManager.getZKTable().removeEnablingTable(tableName, true);
} catch (KeeperException e) {
// TODO : Use HBCK to clear such nodes
LOG.warn("Failed to delete the ENABLING node for the table " + tableName
+ ". The table will remain unusable. Run HBCK to manually fix the problem.");
}
}
// There could be multiple client requests trying to disable or enable
// the table at the same time. Ensure only the first request is honored
// After that, no other requests can be accepted until the table reaches
// DISABLED or ENABLED.
if (!skipTableStateCheck) {
try {
if (!this.assignmentManager.getZKTable().checkDisabledAndSetEnablingTable
(this.tableName)) {
LOG.info("Table " + tableName + " isn't disabled; skipping enable");
throw new TableNotDisabledException(this.tableName);
}
} catch (KeeperException e) {
throw new IOException("Unable to ensure that the table will be" +
" enabling because of a ZooKeeper issue", e);
}
}
success = true;
} finally {
if (!success) {
releaseTableLock();
}
}
return this;
}
@Override
public String toString() {
String name = "UnknownServerName";
if(server != null && server.getServerName() != null) {
name = server.getServerName().toString();
}
return getClass().getSimpleName() + "-" + name + "-" + getSeqid() + "-" +
tableName;
}
@Override
public void process() {
try {
LOG.info("Attempting to enable the table " + this.tableName);
MasterCoprocessorHost cpHost = ((HMaster) this.server)
.getCoprocessorHost();
if (cpHost != null) {
cpHost.preEnableTableHandler(this.tableName);
}
handleEnableTable();
if (cpHost != null) {
cpHost.postEnableTableHandler(this.tableName);
}
} catch (IOException e) {
LOG.error("Error trying to enable the table " + this.tableName, e);
} catch (KeeperException e) {
LOG.error("Error trying to enable the table " + this.tableName, e);
} catch (InterruptedException e) {
LOG.error("Error trying to enable the table " + this.tableName, e);
} finally {
releaseTableLock();
}
}
private void releaseTableLock() {
if (this.tableLock != null) {
try {
this.tableLock.release();
} catch (IOException ex) {
LOG.warn("Could not release the table lock", ex);
}
}
}
private void handleEnableTable() throws IOException, KeeperException, InterruptedException {
// I could check table is disabling and if so, not enable but require
// that user first finish disabling but that might be obnoxious.
// Set table enabling flag up in zk.
this.assignmentManager.getZKTable().setEnablingTable(this.tableName);
boolean done = false;
// Get the regions of this table. We're done when all listed
// tables are onlined.
List<Pair<HRegionInfo, ServerName>> tableRegionsAndLocations = MetaReader
.getTableRegionsAndLocations(this.catalogTracker, tableName, true);
int countOfRegionsInTable = tableRegionsAndLocations.size();
List<HRegionInfo> regions = regionsToAssignWithServerName(tableRegionsAndLocations);
int regionsCount = regions.size();
if (regionsCount == 0) {
done = true;
}
LOG.info("Table '" + this.tableName + "' has " + countOfRegionsInTable
+ " regions, of which " + regionsCount + " are offline.");
BulkEnabler bd = new BulkEnabler(this.server, regions, countOfRegionsInTable,
true);
try {
if (bd.bulkAssign()) {
done = true;
}
} catch (InterruptedException e) {
LOG.warn("Enable operation was interrupted when enabling table '"
+ this.tableName + "'");
// Preserve the interrupt.
Thread.currentThread().interrupt();
}
if (done) {
// Flip the table to enabled.
this.assignmentManager.getZKTable().setEnabledTable(
this.tableName);
LOG.info("Table '" + this.tableName
+ "' was successfully enabled. Status: done=" + done);
} else {
LOG.warn("Table '" + this.tableName
+ "' wasn't successfully enabled. Status: done=" + done);
}
}
/**
* @param regionsInMeta
* @return List of regions neither in transition nor assigned.
* @throws IOException
*/
private List<HRegionInfo> regionsToAssignWithServerName(
final List<Pair<HRegionInfo, ServerName>> regionsInMeta) throws IOException {
ServerManager serverManager = ((HMaster) this.server).getServerManager();
List<HRegionInfo> regions = new ArrayList<HRegionInfo>();
RegionStates regionStates = this.assignmentManager.getRegionStates();
for (Pair<HRegionInfo, ServerName> regionLocation : regionsInMeta) {
HRegionInfo hri = regionLocation.getFirst();
ServerName sn = regionLocation.getSecond();
if (regionStates.isRegionOffline(hri)) {
if (sn != null && serverManager.isServerOnline(sn)) {
this.assignmentManager.addPlan(hri.getEncodedName(), new RegionPlan(hri, null, sn));
}
regions.add(hri);
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Skipping assign for the region " + hri + " during enable table "
+ hri.getTable() + " because its already in tranition or assigned.");
}
}
}
return regions;
}
/**
* Run bulk enable.
*/
class BulkEnabler extends BulkAssigner {
private final List<HRegionInfo> regions;
// Count of regions in table at time this assign was launched.
private final int countOfRegionsInTable;
BulkEnabler(final Server server, final List<HRegionInfo> regions,
final int countOfRegionsInTable, boolean retainAssignment) {
super(server);
this.regions = regions;
this.countOfRegionsInTable = countOfRegionsInTable;
}
@Override
protected void populatePool(ExecutorService pool) throws IOException {
// In case of masterRestart always go with single assign. Going thro
// roundRobinAssignment will use bulkassign which may lead to double assignment.
for (HRegionInfo region : regions) {
if (assignmentManager.getRegionStates()
.isRegionInTransition(region)) {
continue;
}
final HRegionInfo hri = region;
pool.execute(Trace.wrap("BulkEnabler.populatePool",new Runnable() {
public void run() {
assignmentManager.assign(hri, true);
}
}));
}
}
@Override
protected boolean waitUntilDone(long timeout)
throws InterruptedException {
long startTime = System.currentTimeMillis();
long remaining = timeout;
List<HRegionInfo> regions = null;
int lastNumberOfRegions = 0;
while (!server.isStopped() && remaining > 0) {
Thread.sleep(waitingTimeForEvents);
regions = assignmentManager.getRegionStates()
.getRegionsOfTable(tableName);
if (isDone(regions)) break;
// Punt on the timeout as long we make progress
if (regions.size() > lastNumberOfRegions) {
lastNumberOfRegions = regions.size();
timeout += waitingTimeForEvents;
}
remaining = timeout - (System.currentTimeMillis() - startTime);
}
return isDone(regions);
}
private boolean isDone(final List<HRegionInfo> regions) {
return regions != null && regions.size() >= this.countOfRegionsInTable;
}
}
}