HBASE-4365 Add a decent heuristic for region size

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1293099 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/hadoop/hbase/HConstants.java

@@ -227,6 +227,9 @@ public final class HConstants {
   public static final String HREGION_MAX_FILESIZE =
       "hbase.hregion.max.filesize";
 
+  /** Default maximum file size */
+  public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024;
+
   /**
    * The max number of threads used for opening and closing stores or store
    * files in parallel
@@ -240,8 +243,6 @@ public final class HConstants {
    */
   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
 
-  /** Default maximum file size */
-  public static final long DEFAULT_MAX_FILE_SIZE = 256 * 1024 * 1024;
 
   /** Conf key for the memstore size at which we flush the memstore */
   public static final String HREGION_MEMSTORE_FLUSH_SIZE =

src/main/java/org/apache/hadoop/hbase/HTableDescriptor.java

@@ -158,7 +158,7 @@ public class HTableDescriptor implements WritableComparable<HTableDescriptor> {
    * Constant that denotes the maximum default size of the memstore after which 
    * the contents are flushed to the store files
    */
-  public static final long DEFAULT_MEMSTORE_FLUSH_SIZE = 1024*1024*64L;
+  public static final long DEFAULT_MEMSTORE_FLUSH_SIZE = 1024*1024*128L;
 
   private volatile Boolean meta = null;
   private volatile Boolean root = null;

src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -780,6 +780,14 @@ public class HRegion implements HeapSize { // , Writable{
     return this.regionInfo;
   }
 
+  /**
+   * @return Instance of {@link RegionServerServices} used by this HRegion.
+   * Can be null.
+   */
+  RegionServerServices getRegionServerServices() {
+    return this.rsServices;
+  }
+
   /** @return requestsCount for this region */
   public long getRequestsCount() {
     return this.readRequestsCount.get() + this.writeRequestsCount.get();

src/main/java/org/apache/hadoop/hbase/regionserver/IncreasingToUpperBoundRegionSplitPolicy.java

@@ -0,0 +1,112 @@
+/**
+ * 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.regionserver;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.util.Bytes;
+
+/**
+ * Split size is the number of regions that are on this server that all are
+ * of the same table, squared, times the region flush size OR the maximum
+ * region split size, whichever is smaller.  For example, if the flush size
+ * is 128M, then on first flush we will split which will make two regions
+ * that will split when their size is 2 * 2 * 128M = 512M.  If one of these
+ * regions splits, then there are three regions and now the split size is
+ * 3 * 3 * 128M =  1152M, and so on until we reach the configured
+ * maximum filesize and then from there on out, we'll use that.
+ */
+public class IncreasingToUpperBoundRegionSplitPolicy
+extends ConstantSizeRegionSplitPolicy {
+  static final Log LOG =
+    LogFactory.getLog(IncreasingToUpperBoundRegionSplitPolicy.class);
+  private long flushSize;
+
+  @Override
+  protected void configureForRegion(HRegion region) {
+    super.configureForRegion(region);
+    this.flushSize = region.getTableDesc() != null?
+      region.getTableDesc().getMemStoreFlushSize():
+      getConf().getLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE,
+        HTableDescriptor.DEFAULT_MEMSTORE_FLUSH_SIZE);
+  }
+
+  @Override
+  protected boolean shouldSplit() {
+    if (region.shouldForceSplit()) return true;
+    boolean foundABigStore = false;
+    // Get count of regions that have the same common table as this.region
+    int tableRegionsCount = getCountOfCommonTableRegions();
+    // Get size to check
+    long sizeToCheck = getSizeToCheck(tableRegionsCount);
+
+    for (Store store : region.getStores().values()) {
+      // If any of the stores is unable to split (eg they contain reference files)
+      // then don't split
+      if ((!store.canSplit())) {
+        return false;
+      }
+
+      // Mark if any store is big enough
+      long size = store.getSize();
+      if (size > sizeToCheck) {
+        LOG.debug("ShouldSplit because " + store.getColumnFamilyName() +
+          " size=" + size + ", sizeToCheck=" + sizeToCheck +
+          ", regionsWithCommonTable=" + tableRegionsCount);
+        foundABigStore = true;
+        break;
+      }
+    }
+
+    return foundABigStore;
+  }
+
+  /**
+   * @return Region max size or <code>count of regions squared * flushsize, which ever is
+   * smaller; guard against there being zero regions on this server.
+   */
+  long getSizeToCheck(final int tableRegionsCount) {
+    return tableRegionsCount == 0? getDesiredMaxFileSize():
+      Math.min(getDesiredMaxFileSize(),
+        this.flushSize * (tableRegionsCount * tableRegionsCount));
+  }
+
+  /**
+   * @return Count of regions on this server that share the table this.region
+   * belongs to
+   */
+  private int getCountOfCommonTableRegions() {
+    RegionServerServices rss = this.region.getRegionServerServices();
+    // Can be null in tests
+    if (rss == null) return 0;
+    byte [] tablename = this.region.getTableDesc().getName();
+    int tableRegionsCount = 0;
+    try {
+      List<HRegion> hri = rss.getOnlineRegions(tablename);
+      tableRegionsCount = hri == null || hri.isEmpty()? 0: hri.size();
+    } catch (IOException e) {
+      LOG.debug("Failed getOnlineRegions " + Bytes.toString(tablename), e);
+    }
+    return tableRegionsCount;
+  }
+}

src/main/java/org/apache/hadoop/hbase/regionserver/KeyPrefixRegionSplitPolicy.java

@@ -29,7 +29,7 @@ import org.apache.commons.logging.LogFactory;
  * This ensures that a region is not split "inside" a prefix of a row key.
  * I.e. rows can be co-located in a regionb by their prefix.
  */
-public class KeyPrefixRegionSplitPolicy extends ConstantSizeRegionSplitPolicy {
+public class KeyPrefixRegionSplitPolicy extends IncreasingToUpperBoundRegionSplitPolicy {
   private static final Log LOG = LogFactory
       .getLog(KeyPrefixRegionSplitPolicy.class);
   public static String PREFIX_LENGTH_KEY = "prefix_split_key_policy.prefix_length";

src/main/java/org/apache/hadoop/hbase/regionserver/RegionSplitPolicy.java

@@ -33,8 +33,8 @@ import com.google.common.base.Preconditions;
  * {@see ConstantSizeRegionSplitPolicy}
  */
 public abstract class RegionSplitPolicy extends Configured {
-  private static final Class<ConstantSizeRegionSplitPolicy>
-    DEFAULT_SPLIT_POLICY_CLASS = ConstantSizeRegionSplitPolicy.class;
+  private static final Class<? extends RegionSplitPolicy>
+    DEFAULT_SPLIT_POLICY_CLASS = IncreasingToUpperBoundRegionSplitPolicy.class;
 
   /**
    * The region configured for this split policy.

src/main/resources/hbase-default.xml

@@ -389,11 +389,11 @@
   </property>
   <property>
     <name>hbase.hregion.max.filesize</name>
-    <value>1073741824</value>
+    <value>10737418240</value>
     <description>
     Maximum HStoreFile size. If any one of a column families' HStoreFiles has
     grown to exceed this value, the hosting HRegion is split in two.
-    Default: 1G.
+    Default: 10G.
     </description>
   </property>
   <property>

src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionSplitPolicy.java

@@ -17,14 +17,22 @@
  */
 package org.apache.hadoop.hbase.regionserver;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
-import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.TreeMap;
 
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.*;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.junit.Before;
 import org.junit.Test;
@@ -38,14 +46,13 @@ public class TestRegionSplitPolicy {
   private HTableDescriptor htd;
   private HRegion mockRegion;
   private TreeMap<byte[], Store> stores;
+  private static final byte [] TABLENAME = new byte [] {'t'};
 
   @Before
   public void setupMocks() {
     conf = HBaseConfiguration.create();
-
-    HRegionInfo hri = new HRegionInfo(Bytes.toBytes("testtable"));
-
-    htd = new HTableDescriptor();
+    HRegionInfo hri = new HRegionInfo(TABLENAME);
+    htd = new HTableDescriptor(TABLENAME);
     mockRegion = Mockito.mock(HRegion.class);
     Mockito.doReturn(htd).when(mockRegion).getTableDesc();
     Mockito.doReturn(hri).when(mockRegion).getRegionInfo();
@@ -54,6 +61,65 @@ public class TestRegionSplitPolicy {
     Mockito.doReturn(stores).when(mockRegion).getStores();
   }
 
+  @Test
+  public void testIncreasingToUpperBoundRegionSplitPolicy() throws IOException {
+    // Configure IncreasingToUpperBoundRegionSplitPolicy as our split policy
+    conf.set(HConstants.HBASE_REGION_SPLIT_POLICY_KEY,
+      IncreasingToUpperBoundRegionSplitPolicy.class.getName());
+    // Now make it so the mock region has a RegionServerService that will
+    // return 'online regions'.
+    RegionServerServices rss = Mockito.mock(RegionServerServices.class);
+    final List<HRegion> regions = new ArrayList<HRegion>();
+    Mockito.when(rss.getOnlineRegions(TABLENAME)).thenReturn(regions);
+    Mockito.when(mockRegion.getRegionServerServices()).thenReturn(rss);
+    // Set max size for this 'table'.
+    long maxSplitSize = 1024L;
+    htd.setMaxFileSize(maxSplitSize);
+    // Set flush size to 1/4.  IncreasingToUpperBoundRegionSplitPolicy
+    // grows by the square of the number of regions times flushsize each time.
+    long flushSize = maxSplitSize/4;
+    conf.setLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, flushSize);
+    htd.setMemStoreFlushSize(flushSize);
+    // If RegionServerService with no regions in it -- 'online regions' == 0 --
+    // then IncreasingToUpperBoundRegionSplitPolicy should act like a
+    // ConstantSizePolicy
+    IncreasingToUpperBoundRegionSplitPolicy policy =
+      (IncreasingToUpperBoundRegionSplitPolicy)RegionSplitPolicy.create(mockRegion, conf);
+    doConstantSizePolicyTests(policy);
+
+    // Add a store in excess of split size.  Because there are "no regions"
+    // on this server -- rss.getOnlineRegions is 0 -- then we should split
+    // like a constantsizeregionsplitpolicy would
+    Store mockStore = Mockito.mock(Store.class);
+    Mockito.doReturn(2000L).when(mockStore).getSize();
+    Mockito.doReturn(true).when(mockStore).canSplit();
+    stores.put(new byte[]{1}, mockStore);
+    // It should split
+    assertTrue(policy.shouldSplit());
+
+    // Now test that we increase our split size as online regions for a table
+    // grows. With one region, split size should be flushsize.
+    regions.add(mockRegion);
+    Mockito.doReturn(flushSize/2).when(mockStore).getSize();
+    // Should not split since store is 1/2 flush size.
+    assertFalse(policy.shouldSplit());
+    // Set size of store to be > flush size and we should split
+    Mockito.doReturn(flushSize + 1).when(mockStore).getSize();
+    assertTrue(policy.shouldSplit());
+    // Add another region to the 'online regions' on this server and we should
+    // now be no longer be splittable since split size has gone up.
+    regions.add(mockRegion);
+    assertFalse(policy.shouldSplit());
+    // Quadruple (2 squared) the store size and make sure its just over; verify it'll split
+    Mockito.doReturn((flushSize * 2 * 2) + 1).when(mockStore).getSize();
+    assertTrue(policy.shouldSplit());
+
+    // Finally assert that even if loads of regions, we'll split at max size
+    assertEquals(maxSplitSize, policy.getSizeToCheck(1000));
+    // Assert same is true if count of regions is zero.
+    assertEquals(maxSplitSize, policy.getSizeToCheck(0));
+  }
+
   @Test
   public void testCreateDefault() throws IOException {
     conf.setLong(HConstants.HREGION_MAX_FILESIZE, 1234L);
@@ -110,10 +176,16 @@ public class TestRegionSplitPolicy {
   @Test
   public void testConstantSizePolicy() throws IOException {
     htd.setMaxFileSize(1024L);
-
     ConstantSizeRegionSplitPolicy policy =
       (ConstantSizeRegionSplitPolicy)RegionSplitPolicy.create(mockRegion, conf);
+    doConstantSizePolicyTests(policy);
+  }
 
+  /**
+   * Run through tests for a ConstantSizeRegionSplitPolicy
+   * @param policy
+   */
+  private void doConstantSizePolicyTests(final ConstantSizeRegionSplitPolicy policy) {
     // For no stores, should not split
     assertFalse(policy.shouldSplit());
 
@@ -141,6 +213,9 @@ public class TestRegionSplitPolicy {
     // Turn off forceSplit, should not split
     Mockito.doReturn(false).when(mockRegion).shouldForceSplit();
     assertFalse(policy.shouldSplit());
+
+    // Clear families we added above
+    stores.clear();
   }
 
   @Test
@@ -179,4 +254,3 @@ public class TestRegionSplitPolicy {
   public org.apache.hadoop.hbase.ResourceCheckerJUnitRule cu =
     new org.apache.hadoop.hbase.ResourceCheckerJUnitRule();
 }
-