hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/SplitRequest.java

   1 /**
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.regionserver;
  20
  21 import java.security.PrivilegedAction;
  22 import org.apache.hadoop.hbase.HConstants;
  23 import org.apache.hadoop.hbase.TableName;
  24 import org.apache.hadoop.hbase.client.RegionInfo;
  25 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
  26 import org.apache.hadoop.hbase.regionserver.RegionServerServices.RegionStateTransitionContext;
  27 import org.apache.hadoop.hbase.security.User;
  28 import org.apache.hadoop.hbase.util.Bytes;
  29 import org.apache.yetus.audience.InterfaceAudience;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
  34
  35 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
  36
  37 /**
  38  * Handles processing region splits. Put in a queue, owned by HRegionServer.
  39  */
  40 @InterfaceAudience.Private
  41 class SplitRequest implements Runnable {
  42   private static final Logger LOG = LoggerFactory.getLogger(SplitRequest.class);
  43   private final RegionInfo parent;
  44   private final byte[] midKey;
  45   private final HRegionServer server;
  46   private final User user;
  47
  48   SplitRequest(Region region, byte[] midKey, HRegionServer hrs, User user) {
  49     Preconditions.checkNotNull(hrs);
  50     this.parent = region.getRegionInfo();
  51     this.midKey = midKey;
  52     this.server = hrs;
  53     this.user = user;
  54   }
  55
  56   @Override
  57   public String toString() {
  58     return "regionName=" + parent + ", midKey=" + Bytes.toStringBinary(midKey);
  59   }
  60
  61   private void doSplitting() {
  62     server.getMetrics().incrSplitRequest();
  63     if (user != null && user.getUGI() != null) {
  64       user.getUGI().doAs((PrivilegedAction<Void>) () -> {
  65         requestRegionSplit();
  66         return null;
  67       });
  68     } else {
  69       requestRegionSplit();
  70     }
  71   }
  72
  73   private void requestRegionSplit() {
  74     final TableName table = parent.getTable();
  75     final RegionInfo hri_a = RegionInfoBuilder.newBuilder(table)
  76         .setStartKey(parent.getStartKey())
  77         .setEndKey(midKey)
  78         .build();
  79     final RegionInfo hri_b = RegionInfoBuilder.newBuilder(table)
  80         .setStartKey(midKey)
  81         .setEndKey(parent.getEndKey())
  82         .build();
  83     // Send the split request to the master. the master will do the validation on the split-key.
  84     // The parent region will be unassigned and the two new regions will be assigned.
  85     // hri_a and hri_b objects may not reflect the regions that will be created, those objects
  86     // are created just to pass the information to the reportRegionStateTransition().
  87     if (!server.reportRegionStateTransition(new RegionStateTransitionContext(
  88       TransitionCode.READY_TO_SPLIT, HConstants.NO_SEQNUM, -1, parent, hri_a, hri_b))) {
  89       LOG.error("Unable to ask master to split " + parent.getRegionNameAsString());
  90     }
  91   }
  92
  93   @Override
  94   public void run() {
  95     if (this.server.isStopping() || this.server.isStopped()) {
  96       LOG.debug("Skipping split because server is stopping=" +
  97         this.server.isStopping() + " or stopped=" + this.server.isStopped());
  98       return;
  99     }
 100
 101     doSplitting();
 102   }
 103 }