/**
*
* 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.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
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.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.TableNotFoundException;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
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.GeneralBulkAssigner;
import org.apache.hadoop.hbase.master.HMaster;
import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
import org.apache.hadoop.hbase.master.MasterServices;
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.protobuf.generated.ZooKeeperProtos;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
/**
* 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 boolean skipTableStateCheck = false;
private TableLock tableLock;
private MasterServices services;
public EnableTableHandler(Server server, TableName tableName,
AssignmentManager assignmentManager, TableLockManager tableLockManager,
boolean skipTableStateCheck) {
super(server, EventType.C_M_ENABLE_TABLE);
this.tableName = tableName;
this.assignmentManager = assignmentManager;
this.tableLockManager = tableLockManager;
this.skipTableStateCheck = skipTableStateCheck;
}
public EnableTableHandler(MasterServices services, TableName tableName,
AssignmentManager assignmentManager,
TableLockManager tableLockManager, boolean skipTableStateCheck) {
this((Server)services, tableName, assignmentManager, tableLockManager,
skipTableStateCheck);
this.services = services;
}
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 (!MetaTableAccessor.tableExists(this.server.getConnection(), tableName)) {
// retainAssignment is true only during recovery. In normal case it is false
if (!this.skipTableStateCheck) {
throw new TableNotFoundException(tableName);
}
try {
this.assignmentManager.getTableStateManager().checkAndRemoveTableState(tableName,
ZooKeeperProtos.Table.State.ENABLING, true);
throw new TableNotFoundException(tableName);
} catch (CoordinatedStateException 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.getTableStateManager().setTableStateIfInStates(
this.tableName, ZooKeeperProtos.Table.State.ENABLING,
ZooKeeperProtos.Table.State.DISABLED)) {
LOG.info("Table " + tableName + " isn't disabled; skipping enable");
throw new TableNotDisabledException(this.tableName);
}
} catch (CoordinatedStateException e) {
throw new IOException("Unable to ensure that the table will be" +
" enabling because of a coordination engine 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)
.getMasterCoprocessorHost();
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 (CoordinatedStateException 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, CoordinatedStateException,
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.getTableStateManager().setTableState(this.tableName,
ZooKeeperProtos.Table.State.ENABLING);
boolean done = false;
ServerManager serverManager = ((HMaster)this.server).getServerManager();
// Get the regions of this table. We're done when all listed
// tables are onlined.
List<Pair<HRegionInfo, ServerName>> tableRegionsAndLocations;
if (TableName.META_TABLE_NAME.equals(tableName)) {
tableRegionsAndLocations = new MetaTableLocator().getMetaRegionsAndLocations(
server.getZooKeeper());
} else {
tableRegionsAndLocations = MetaTableAccessor.getTableRegionsAndLocations(
server.getZooKeeper(), server.getConnection(), tableName, true);
}
int countOfRegionsInTable = tableRegionsAndLocations.size();
Map<HRegionInfo, ServerName> regionsToAssign =
regionsToAssignWithServerName(tableRegionsAndLocations);
if (services != null) {
// need to potentially create some regions for the replicas
List<HRegionInfo> unrecordedReplicas = AssignmentManager.replicaRegionsNotRecordedInMeta(
new HashSet<HRegionInfo>(regionsToAssign.keySet()), services);
Map<ServerName, List<HRegionInfo>> srvToUnassignedRegs =
this.assignmentManager.getBalancer().roundRobinAssignment(unrecordedReplicas,
serverManager.getOnlineServersList());
if (srvToUnassignedRegs != null) {
for (Map.Entry<ServerName, List<HRegionInfo>> entry : srvToUnassignedRegs.entrySet()) {
for (HRegionInfo h : entry.getValue()) {
regionsToAssign.put(h, entry.getKey());
}
}
}
}
int regionsCount = regionsToAssign.size();
if (regionsCount == 0) {
done = true;
}
LOG.info("Table '" + this.tableName + "' has " + countOfRegionsInTable
+ " regions, of which " + regionsCount + " are offline.");
List<ServerName> onlineServers = serverManager.createDestinationServersList();
Map<ServerName, List<HRegionInfo>> bulkPlan =
this.assignmentManager.getBalancer().retainAssignment(regionsToAssign, onlineServers);
if (bulkPlan != null) {
LOG.info("Bulk assigning " + regionsCount + " region(s) across " + bulkPlan.size()
+ " server(s), retainAssignment=true");
BulkAssigner ba =
new GeneralBulkAssigner(this.server, bulkPlan, this.assignmentManager, true);
try {
if (ba.bulkAssign()) {
done = true;
}
} catch (InterruptedException e) {
LOG.warn("Enable operation was interrupted when enabling table '"
+ this.tableName + "'");
// Preserve the interrupt.
Thread.currentThread().interrupt();
}
} else {
done = true;
LOG.info("Balancer was unable to find suitable servers for table " + tableName
+ ", leaving unassigned");
}
if (done) {
// Flip the table to enabled.
this.assignmentManager.getTableStateManager().setTableState(
this.tableName, ZooKeeperProtos.Table.State.ENABLED);
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 Map<HRegionInfo, ServerName> regionsToAssignWithServerName(
final List<Pair<HRegionInfo, ServerName>> regionsInMeta) throws IOException {
Map<HRegionInfo, ServerName> regionsToAssign =
new HashMap<HRegionInfo, ServerName>(regionsInMeta.size());
RegionStates regionStates = this.assignmentManager.getRegionStates();
for (Pair<HRegionInfo, ServerName> regionLocation : regionsInMeta) {
HRegionInfo hri = regionLocation.getFirst();
ServerName sn = regionLocation.getSecond();
if (regionStates.isRegionOffline(hri)) {
regionsToAssign.put(hri, sn);
} 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 regionsToAssign;
}
}