/**
*
* 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;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.RegionLocations;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.MetaTableAccessor.Visitor;
import org.apache.hadoop.hbase.client.HConnection;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.master.balancer.FavoredNodeAssignmentHelper;
import org.apache.hadoop.hbase.master.balancer.FavoredNodesPlan;
/**
* Used internally for reading meta and constructing datastructures that are
* then queried, for things like regions to regionservers, table to regions, etc.
* It also records the favored nodes mapping for regions.
*
*/
@InterfaceAudience.Private
public class SnapshotOfRegionAssignmentFromMeta {
private static final Log LOG = LogFactory.getLog(SnapshotOfRegionAssignmentFromMeta.class
.getName());
private final HConnection hConnection;
/** the table name to region map */
private final Map<TableName, List<HRegionInfo>> tableToRegionMap;
/** the region to region server map */
//private final Map<HRegionInfo, ServerName> regionToRegionServerMap;
private Map<HRegionInfo, ServerName> regionToRegionServerMap;
/** the region name to region info map */
private final Map<String, HRegionInfo> regionNameToRegionInfoMap;
/** the regionServer to region map */
private final Map<ServerName, List<HRegionInfo>> regionServerToRegionMap;
/** the existing assignment plan in the hbase:meta region */
private final FavoredNodesPlan existingAssignmentPlan;
private final Set<TableName> disabledTables;
private final boolean excludeOfflinedSplitParents;
public SnapshotOfRegionAssignmentFromMeta(HConnection hConnection) {
this(hConnection, new HashSet<TableName>(), false);
}
public SnapshotOfRegionAssignmentFromMeta(HConnection hConnection, Set<TableName> disabledTables,
boolean excludeOfflinedSplitParents) {
this.hConnection = hConnection;
tableToRegionMap = new HashMap<TableName, List<HRegionInfo>>();
regionToRegionServerMap = new HashMap<HRegionInfo, ServerName>();
regionServerToRegionMap = new HashMap<ServerName, List<HRegionInfo>>();
regionNameToRegionInfoMap = new TreeMap<String, HRegionInfo>();
existingAssignmentPlan = new FavoredNodesPlan();
this.disabledTables = disabledTables;
this.excludeOfflinedSplitParents = excludeOfflinedSplitParents;
}
/**
* Initialize the region assignment snapshot by scanning the hbase:meta table
* @throws IOException
*/
public void initialize() throws IOException {
LOG.info("Start to scan the hbase:meta for the current region assignment " +
"snappshot");
// TODO: at some point this code could live in the MetaTableAccessor
Visitor v = new Visitor() {
@Override
public boolean visit(Result result) throws IOException {
try {
if (result == null || result.isEmpty()) return true;
RegionLocations rl = MetaTableAccessor.getRegionLocations(result);
if (rl == null) return true;
HRegionInfo hri = rl.getRegionLocation(0).getRegionInfo();
if (hri == null) return true;
if (hri.getTable() == null) return true;
if (disabledTables.contains(hri.getTable())) {
return true;
}
// Are we to include split parents in the list?
if (excludeOfflinedSplitParents && hri.isSplit()) return true;
HRegionLocation[] hrls = rl.getRegionLocations();
// Add the current assignment to the snapshot for all replicas
for (int i = 0; i < hrls.length; i++) {
if (hrls[i] == null) continue;
hri = hrls[i].getRegionInfo();
if (hri == null) continue;
addAssignment(hri, hrls[i].getServerName());
addRegion(hri);
}
// the code below is to handle favored nodes
byte[] favoredNodes = result.getValue(HConstants.CATALOG_FAMILY,
FavoredNodeAssignmentHelper.FAVOREDNODES_QUALIFIER);
if (favoredNodes == null) return true;
// Add the favored nodes into assignment plan
ServerName[] favoredServerList =
FavoredNodeAssignmentHelper.getFavoredNodesList(favoredNodes);
// Add the favored nodes into assignment plan
existingAssignmentPlan.updateFavoredNodesMap(hri,
Arrays.asList(favoredServerList));
return true;
} catch (RuntimeException e) {
LOG.error("Catche remote exception " + e.getMessage() +
" when processing" + result);
throw e;
}
}
};
// Scan hbase:meta to pick up user regions
MetaTableAccessor.fullScan(hConnection, v);
//regionToRegionServerMap = regions;
LOG.info("Finished to scan the hbase:meta for the current region assignment" +
"snapshot");
}
private void addRegion(HRegionInfo regionInfo) {
// Process the region name to region info map
regionNameToRegionInfoMap.put(regionInfo.getRegionNameAsString(), regionInfo);
// Process the table to region map
TableName tableName = regionInfo.getTable();
List<HRegionInfo> regionList = tableToRegionMap.get(tableName);
if (regionList == null) {
regionList = new ArrayList<HRegionInfo>();
}
// Add the current region info into the tableToRegionMap
regionList.add(regionInfo);
tableToRegionMap.put(tableName, regionList);
}
private void addAssignment(HRegionInfo regionInfo, ServerName server) {
// Process the region to region server map
regionToRegionServerMap.put(regionInfo, server);
if (server == null) return;
// Process the region server to region map
List<HRegionInfo> regionList = regionServerToRegionMap.get(server);
if (regionList == null) {
regionList = new ArrayList<HRegionInfo>();
}
regionList.add(regionInfo);
regionServerToRegionMap.put(server, regionList);
}
/**
* Get the regioninfo for a region
* @return the regioninfo
*/
public Map<String, HRegionInfo> getRegionNameToRegionInfoMap() {
return this.regionNameToRegionInfoMap;
}
/**
* Get regions for tables
* @return a mapping from table to regions
*/
public Map<TableName, List<HRegionInfo>> getTableToRegionMap() {
return tableToRegionMap;
}
/**
* Get region to region server map
* @return region to region server map
*/
public Map<HRegionInfo, ServerName> getRegionToRegionServerMap() {
return regionToRegionServerMap;
}
/**
* Get regionserver to region map
* @return regionserver to region map
*/
public Map<ServerName, List<HRegionInfo>> getRegionServerToRegionMap() {
return regionServerToRegionMap;
}
/**
* Get the favored nodes plan
* @return the existing favored nodes plan
*/
public FavoredNodesPlan getExistingAssignmentPlan() {
return this.existingAssignmentPlan;
}
/**
* Get the table set
* @return the table set
*/
public Set<TableName> getTableSet() {
return this.tableToRegionMap.keySet();
}
}