Source code

001/**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *     http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019
020package org.apache.hadoop.hbase.master.assignment;
021
022import java.io.IOException;
023import java.util.Collections;
024import java.util.List;
025
026import org.apache.hadoop.hbase.Cell;
027import org.apache.hadoop.hbase.CellBuilderFactory;
028import org.apache.hadoop.hbase.CellBuilderType;
029import org.apache.hadoop.hbase.HConstants;
030import org.apache.hadoop.hbase.HRegionLocation;
031import org.apache.hadoop.hbase.MetaTableAccessor;
032import org.apache.hadoop.hbase.RegionLocations;
033import org.apache.hadoop.hbase.ServerName;
034import org.apache.hadoop.hbase.TableName;
035import org.apache.hadoop.hbase.client.Put;
036import org.apache.hadoop.hbase.client.RegionInfo;
037import org.apache.hadoop.hbase.client.Result;
038import org.apache.hadoop.hbase.client.Table;
039import org.apache.hadoop.hbase.client.TableDescriptor;
040import org.apache.hadoop.hbase.master.MasterServices;
041import org.apache.hadoop.hbase.master.RegionState.State;
042import org.apache.hadoop.hbase.procedure2.Procedure;
043import org.apache.hadoop.hbase.procedure2.util.StringUtils;
044import org.apache.hadoop.hbase.util.Bytes;
045import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
046import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
047import org.apache.yetus.audience.InterfaceAudience;
048import org.apache.zookeeper.KeeperException;
049import org.slf4j.Logger;
050import org.slf4j.LoggerFactory;
051
052import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
053import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
054
055/**
056 * Store Region State to hbase:meta table.
057 */
058@InterfaceAudience.Private
059public class RegionStateStore {
060  private static final Logger LOG = LoggerFactory.getLogger(RegionStateStore.class);
061
062  /** The delimiter for meta columns for replicaIds &gt; 0 */
063  protected static final char META_REPLICA_ID_DELIMITER = '_';
064
065  private final MasterServices master;
066
067  public RegionStateStore(final MasterServices master) {
068    this.master = master;
069  }
070
071  public interface RegionStateVisitor {
072    void visitRegionState(Result result, RegionInfo regionInfo, State state,
073      ServerName regionLocation, ServerName lastHost, long openSeqNum);
074  }
075
076  public void visitMeta(final RegionStateVisitor visitor) throws IOException {
077    MetaTableAccessor.fullScanRegions(master.getConnection(), new MetaTableAccessor.Visitor() {
078      final boolean isDebugEnabled = LOG.isDebugEnabled();
079
080      @Override
081      public boolean visit(final Result r) throws IOException {
082        if (r !=  null && !r.isEmpty()) {
083          long st = 0;
084          if (LOG.isTraceEnabled()) {
085            st = System.currentTimeMillis();
086          }
087          visitMetaEntry(visitor, r);
088          if (LOG.isTraceEnabled()) {
089            long et = System.currentTimeMillis();
090            LOG.trace("[T] LOAD META PERF " + StringUtils.humanTimeDiff(et - st));
091          }
092        } else if (isDebugEnabled) {
093          LOG.debug("NULL result from meta - ignoring but this is strange.");
094        }
095        return true;
096      }
097    });
098  }
099
100  private void visitMetaEntry(final RegionStateVisitor visitor, final Result result)
101      throws IOException {
102    final RegionLocations rl = MetaTableAccessor.getRegionLocations(result);
103    if (rl == null) return;
104
105    final HRegionLocation[] locations = rl.getRegionLocations();
106    if (locations == null) return;
107
108    for (int i = 0; i < locations.length; ++i) {
109      final HRegionLocation hrl = locations[i];
110      if (hrl == null) continue;
111
112      final RegionInfo regionInfo = hrl.getRegion();
113      if (regionInfo == null) continue;
114
115      final int replicaId = regionInfo.getReplicaId();
116      final State state = getRegionState(result, replicaId);
117
118      final ServerName lastHost = hrl.getServerName();
119      final ServerName regionLocation = getRegionServer(result, replicaId);
120      final long openSeqNum = hrl.getSeqNum();
121
122      // TODO: move under trace, now is visible for debugging
123      LOG.info(
124        "Load hbase:meta entry region={}, regionState={}, lastHost={}, " +
125          "regionLocation={}, openSeqNum={}",
126        regionInfo.getEncodedName(), state, lastHost, regionLocation, openSeqNum);
127      visitor.visitRegionState(result, regionInfo, state, regionLocation, lastHost, openSeqNum);
128    }
129  }
130
131  public void updateRegionLocation(RegionStates.RegionStateNode regionStateNode)
132      throws IOException {
133    if (regionStateNode.getRegionInfo().isMetaRegion()) {
134      updateMetaLocation(regionStateNode.getRegionInfo(), regionStateNode.getRegionLocation(),
135        regionStateNode.getState());
136    } else {
137      long openSeqNum = regionStateNode.getState() == State.OPEN ? regionStateNode.getOpenSeqNum()
138        : HConstants.NO_SEQNUM;
139      updateUserRegionLocation(regionStateNode.getRegionInfo(), regionStateNode.getState(),
140          regionStateNode.getRegionLocation(), openSeqNum,
141          // The regionStateNode may have no procedure in a test scenario; allow for this.
142          regionStateNode.getProcedure() != null ? regionStateNode.getProcedure().getProcId()
143              : Procedure.NO_PROC_ID);
144    }
145  }
146
147  private void updateMetaLocation(RegionInfo regionInfo, ServerName serverName, State state)
148      throws IOException {
149    try {
150      MetaTableLocator.setMetaLocation(master.getZooKeeper(), serverName, regionInfo.getReplicaId(),
151        state);
152    } catch (KeeperException e) {
153      throw new IOException(e);
154    }
155  }
156
157  private void updateUserRegionLocation(final RegionInfo regionInfo, final State state,
158      final ServerName regionLocation, final long openSeqNum,
159      final long pid)
160      throws IOException {
161    long time = EnvironmentEdgeManager.currentTime();
162    final int replicaId = regionInfo.getReplicaId();
163    final Put put = new Put(MetaTableAccessor.getMetaKeyForRegion(regionInfo), time);
164    MetaTableAccessor.addRegionInfo(put, regionInfo);
165    final StringBuilder info =
166      new StringBuilder("pid=").append(pid).append(" updating hbase:meta row=")
167        .append(regionInfo.getEncodedName()).append(", regionState=").append(state);
168    if (openSeqNum >= 0) {
169      Preconditions.checkArgument(state == State.OPEN && regionLocation != null,
170          "Open region should be on a server");
171      MetaTableAccessor.addLocation(put, regionLocation, openSeqNum, replicaId);
172      info.append(", openSeqNum=").append(openSeqNum);
173      info.append(", regionLocation=").append(regionLocation);
174    } else if (regionLocation != null) {
175      // Ideally, if no regionLocation, write null to the hbase:meta but this will confuse clients
176      // currently; they want a server to hit. TODO: Make clients wait if no location.
177      put.add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
178          .setRow(put.getRow())
179          .setFamily(HConstants.CATALOG_FAMILY)
180          .setQualifier(getServerNameColumn(replicaId))
181          .setTimestamp(put.getTimestamp())
182          .setType(Cell.Type.Put)
183          .setValue(Bytes.toBytes(regionLocation.getServerName()))
184          .build());
185      info.append(", regionLocation=").append(regionLocation);
186    }
187    put.add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
188        .setRow(put.getRow())
189        .setFamily(HConstants.CATALOG_FAMILY)
190        .setQualifier(getStateColumn(replicaId))
191        .setTimestamp(put.getTimestamp())
192        .setType(Cell.Type.Put)
193        .setValue(Bytes.toBytes(state.name()))
194        .build());
195    LOG.info(info.toString());
196    updateRegionLocation(regionInfo, state, put);
197  }
198
199  private void updateRegionLocation(RegionInfo regionInfo, State state, Put put)
200      throws IOException {
201    try (Table table = master.getConnection().getTable(TableName.META_TABLE_NAME)) {
202      table.put(put);
203    } catch (IOException e) {
204      // TODO: Revist!!!! Means that if a server is loaded, then we will abort our host!
205      // In tests we abort the Master!
206      String msg = String.format("FAILED persisting region=%s state=%s",
207        regionInfo.getShortNameToLog(), state);
208      LOG.error(msg, e);
209      master.abort(msg, e);
210      throw e;
211    }
212  }
213
214  // ============================================================================================
215  //  Update Region Splitting State helpers
216  // ============================================================================================
217  public void splitRegion(final RegionInfo parent, final RegionInfo hriA,
218      final RegionInfo hriB, final ServerName serverName)  throws IOException {
219    final TableDescriptor htd = getTableDescriptor(parent.getTable());
220    MetaTableAccessor.splitRegion(master.getConnection(), parent, hriA, hriB, serverName,
221        getRegionReplication(htd));
222  }
223
224  // ============================================================================================
225  //  Update Region Merging State helpers
226  // ============================================================================================
227  public void mergeRegions(RegionInfo child, RegionInfo [] parents, ServerName serverName)
228      throws IOException {
229    TableDescriptor htd = getTableDescriptor(child.getTable());
230    MetaTableAccessor.mergeRegions(master.getConnection(), child, parents, serverName,
231        getRegionReplication(htd));
232  }
233
234  // ============================================================================================
235  //  Delete Region State helpers
236  // ============================================================================================
237  public void deleteRegion(final RegionInfo regionInfo) throws IOException {
238    deleteRegions(Collections.singletonList(regionInfo));
239  }
240
241  public void deleteRegions(final List<RegionInfo> regions) throws IOException {
242    MetaTableAccessor.deleteRegionInfos(master.getConnection(), regions);
243  }
244
245  // ==========================================================================
246  //  Table Descriptors helpers
247  // ==========================================================================
248  private int getRegionReplication(final TableDescriptor htd) {
249    return (htd != null) ? htd.getRegionReplication() : 1;
250  }
251
252  private TableDescriptor getTableDescriptor(final TableName tableName) throws IOException {
253    return master.getTableDescriptors().get(tableName);
254  }
255
256  // ==========================================================================
257  //  Server Name
258  // ==========================================================================
259
260  /**
261   * Returns the {@link ServerName} from catalog table {@link Result}
262   * where the region is transitioning. It should be the same as
263   * {@link MetaTableAccessor#getServerName(Result,int)} if the server is at OPEN state.
264   * @param r Result to pull the transitioning server name from
265   * @return A ServerName instance or {@link MetaTableAccessor#getServerName(Result,int)}
266   * if necessary fields not found or empty.
267   */
268  static ServerName getRegionServer(final Result r, int replicaId) {
269    final Cell cell = r.getColumnLatestCell(HConstants.CATALOG_FAMILY,
270        getServerNameColumn(replicaId));
271    if (cell == null || cell.getValueLength() == 0) {
272      RegionLocations locations = MetaTableAccessor.getRegionLocations(r);
273      if (locations != null) {
274        HRegionLocation location = locations.getRegionLocation(replicaId);
275        if (location != null) {
276          return location.getServerName();
277        }
278      }
279      return null;
280    }
281    return ServerName.parseServerName(Bytes.toString(cell.getValueArray(),
282      cell.getValueOffset(), cell.getValueLength()));
283  }
284
285  private static byte[] getServerNameColumn(int replicaId) {
286    return replicaId == 0
287        ? HConstants.SERVERNAME_QUALIFIER
288        : Bytes.toBytes(HConstants.SERVERNAME_QUALIFIER_STR + META_REPLICA_ID_DELIMITER
289          + String.format(RegionInfo.REPLICA_ID_FORMAT, replicaId));
290  }
291
292  // ==========================================================================
293  //  Region State
294  // ==========================================================================
295
296  /**
297   * Pull the region state from a catalog table {@link Result}.
298   * @param r Result to pull the region state from
299   * @return the region state, or null if unknown.
300   */
301  @VisibleForTesting
302  public static State getRegionState(final Result r, int replicaId) {
303    Cell cell = r.getColumnLatestCell(HConstants.CATALOG_FAMILY, getStateColumn(replicaId));
304    if (cell == null || cell.getValueLength() == 0) {
305      return null;
306    }
307    return State.valueOf(Bytes.toString(cell.getValueArray(), cell.getValueOffset(),
308        cell.getValueLength()));
309  }
310
311  private static byte[] getStateColumn(int replicaId) {
312    return replicaId == 0
313        ? HConstants.STATE_QUALIFIER
314        : Bytes.toBytes(HConstants.STATE_QUALIFIER_STR + META_REPLICA_ID_DELIMITER
315          + String.format(RegionInfo.REPLICA_ID_FORMAT, replicaId));
316  }
317}