HBASE-26304: Reflect out of band locality improvements in metrics and balancer

Author: bbeaudreault

hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/RegionHDFSBlockLocationFinder.java

@@ -32,6 +32,8 @@
 import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.hbase.ClusterMetrics;
 import org.apache.hadoop.hbase.HDFSBlocksDistribution;
+import org.apache.hadoop.hbase.RegionMetrics;
+import org.apache.hadoop.hbase.ServerMetrics;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RegionInfo;
@@ -58,6 +60,7 @@
 class RegionHDFSBlockLocationFinder extends Configured {
   private static final Logger LOG = LoggerFactory.getLogger(RegionHDFSBlockLocationFinder.class);
   private static final long CACHE_TIME = 240 * 60 * 1000;
+  private static final float EPSILON = 0.0001f;
   private static final HDFSBlocksDistribution EMPTY_BLOCK_DISTRIBUTION =
     new HDFSBlocksDistribution();
   private volatile ClusterMetrics status;
@@ -110,12 +113,68 @@ void setClusterInfoProvider(ClusterInfoProvider provider) {
 
   void setClusterMetrics(ClusterMetrics status) {
     long currentTime = EnvironmentEdgeManager.currentTime();
-    this.status = status;
+
     if (currentTime > lastFullRefresh + (CACHE_TIME / 2)) {
+      this.status = status;
       // Only count the refresh if it includes user tables ( eg more than meta and namespace ).
       lastFullRefresh = scheduleFullRefresh() ? currentTime : lastFullRefresh;
+    } else {
+      refreshLocalityChangedRegions(this.status, status);
+      this.status = status;
+    }
+  }
+
+  /**
+   * If locality for a region has changed, that pretty certainly means our cache is out of date.
+   * Compare oldStatus and newStatus, refreshing any regions which have moved or changed locality.
+   */
+  private void refreshLocalityChangedRegions(ClusterMetrics oldStatus, ClusterMetrics newStatus) {
+    if (oldStatus == null || newStatus == null) {
+      LOG.debug("Skipping locality-based refresh due to oldStatus={}, newStatus={}", oldStatus, newStatus);
+      return;
+    }
+
+    Map<ServerName, ServerMetrics> oldServers = oldStatus.getLiveServerMetrics();
+    Map<ServerName, ServerMetrics> newServers = newStatus.getLiveServerMetrics();
+
+    Map<String, RegionInfo> regionsByName = new HashMap<>(cache.asMap().size());
+    for (RegionInfo regionInfo : cache.asMap().keySet()) {
+      regionsByName.put(regionInfo.getEncodedName(), regionInfo);
+    }
+
+    for (Map.Entry<ServerName, ServerMetrics> serverEntry : newServers.entrySet()) {
+      Map<byte[], RegionMetrics> newRegions = serverEntry.getValue().getRegionMetrics();
+      for (Map.Entry<byte[], RegionMetrics> regionEntry : newRegions.entrySet()) {
+        String encodedName = RegionInfo.encodeRegionName(regionEntry.getKey());
+        RegionInfo region = regionsByName.get(encodedName);
+        if (region == null) {
+          continue;
+        }
+
+        float newLocality = regionEntry.getValue().getDataLocality();
+        float oldLocality = getOldLocality(serverEntry.getKey(), regionEntry.getKey(), oldServers);
+
+        if (Math.abs(newLocality - oldLocality) > EPSILON) {
+          LOG.debug("Locality for region {} changed from {} to {}, refreshing cache",
+            region.getEncodedName(), oldLocality, newLocality);
+          cache.refresh(region);
+        }
+      }
+
+    }
+  }
+
+  private float getOldLocality(ServerName newServer, byte[] regionName, Map<ServerName, ServerMetrics> oldServers) {
+    ServerMetrics serverMetrics = oldServers.get(newServer);
+    if (serverMetrics == null) {
+      return -1f;
+    }
+    RegionMetrics regionMetrics = serverMetrics.getRegionMetrics().get(regionName);
+    if (regionMetrics == null) {
+      return -1f;
     }
 
+    return regionMetrics.getDataLocality();
   }
 
   /**

hbase-balancer/src/test/java/org/apache/hadoop/hbase/master/balancer/TestRegionHDFSBlockLocationFinder.java

@@ -19,6 +19,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
@@ -37,6 +38,7 @@
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HDFSBlocksDistribution;
 import org.apache.hadoop.hbase.HDFSBlocksDistribution.HostAndWeight;
+import org.apache.hadoop.hbase.RegionMetrics;
 import org.apache.hadoop.hbase.ServerMetrics;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
@@ -204,4 +206,56 @@ public void testGetTopBlockLocations() {
       }
     }
   }
+
+  @Test
+  public void testRefreshRegionsWithChangedLocality() {
+    ServerName testServer = ServerName.valueOf("host-0", 12345, 12345);
+    RegionInfo testRegion = REGIONS.get(0);
+
+    Map<RegionInfo, HDFSBlocksDistribution> cache = new HashMap<>();
+    for (RegionInfo region : REGIONS) {
+      HDFSBlocksDistribution hbd = finder.getBlockDistribution(region);
+      assertHostAndWeightEquals(generate(region), hbd);
+      cache.put(region, hbd);
+    }
+
+    finder.setClusterMetrics(getMetricsWithLocality(testServer, testRegion.getRegionName(), 0.123f));
+
+    // everything should be cached, because metrics were null before
+    for (RegionInfo region : REGIONS) {
+      HDFSBlocksDistribution hbd = finder.getBlockDistribution(region);
+      assertSame(cache.get(region), hbd);
+    }
+
+    finder.setClusterMetrics(getMetricsWithLocality(testServer, testRegion.getRegionName(), 0.345f));
+
+    // locality changed just for our test region, so it should no longer be the same
+    for (RegionInfo region : REGIONS) {
+      HDFSBlocksDistribution hbd = finder.getBlockDistribution(region);
+      if (region.equals(testRegion)) {
+        assertNotSame(cache.get(region), hbd);
+      } else {
+        assertSame(cache.get(region), hbd);
+      }
+    }
+  }
+
+  private ClusterMetrics getMetricsWithLocality(ServerName serverName, byte[] region, float locality) {
+    RegionMetrics regionMetrics = mock(RegionMetrics.class);
+    when(regionMetrics.getDataLocality()).thenReturn(locality);
+
+    Map<byte[], RegionMetrics> regionMetricsMap = new HashMap<>();
+    regionMetricsMap.put(region, regionMetrics);
+
+    ServerMetrics serverMetrics = mock(ServerMetrics.class);
+    when(serverMetrics.getRegionMetrics()).thenReturn(regionMetricsMap);
+
+    Map<ServerName, ServerMetrics> serverMetricsMap = new HashMap<>();
+    serverMetricsMap.put(serverName, serverMetrics);
+
+    ClusterMetrics metrics = mock(ClusterMetrics.class);
+    when(metrics.getLiveServerMetrics()).thenReturn(serverMetricsMap);
+
+    return metrics;
+  }
 }

hbase-common/src/main/resources/hbase-default.xml

@@ -2042,4 +2042,23 @@ possible configurations would overwhelm and obscure the important.
       the ring buffer is indicated by config: hbase.master.balancer.rejection.queue.size
     </description>
   </property>
+  <property>
+    <name>hbase.locality.inputstream.derive.enabled</name>
+    <value>false</value>
+    <description>
+      If true, derive StoreFile locality metrics from the underlying DFSInputStream
+      backing reads for that StoreFile. This value will update as the DFSInputStream's
+      block locations are updated over time. Otherwise, locality is computed on StoreFile
+      open, and cached until the StoreFile is closed.
+    </description>
+  </property>
+  <property>
+    <name>hbase.locality.inputstream.derive.cache.period</name>
+    <value>60000</value>
+    <description>
+      If deriving StoreFile locality metrics from the underlying DFSInputStream, how
+      long should the derived values be cached for. The derivation process may involve
+      hitting the namenode, if the DFSInputStream's block list is incomplete.
+    </description>
+  </property>
 </configuration>

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

@@ -29,6 +29,7 @@
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
@@ -43,6 +44,7 @@
 import org.apache.hadoop.hbase.io.hfile.ReaderContext.ReaderType;
 import org.apache.hadoop.hbase.util.BloomFilterFactory;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -127,6 +129,7 @@ public class HStoreFile implements StoreFile {
 
   // StoreFile.Reader
   private volatile StoreFileReader initialReader;
+  private volatile InputStreamBlockDistribution initialReaderBlockDistribution = null;
 
   // Block cache configuration and reference.
   private final CacheConfig cacheConf;
@@ -344,7 +347,11 @@ public OptionalLong getBulkLoadTimestamp() {
    *         file is opened.
    */
   public HDFSBlocksDistribution getHDFSBlockDistribution() {
-    return this.fileInfo.getHDFSBlockDistribution();
+    if (initialReaderBlockDistribution != null) {
+      return initialReaderBlockDistribution.getHDFSBlockDistribution();
+    } else {
+      return this.fileInfo.getHDFSBlockDistribution();
+    }
   }
 
   /**
@@ -362,6 +369,15 @@ private void open() throws IOException {
       fileInfo.getHFileInfo().initMetaAndIndex(reader.getHFileReader());
     }
     this.initialReader = fileInfo.postStoreFileReaderOpen(context, cacheConf, reader);
+
+    if (InputStreamBlockDistribution.isEnabled(fileInfo.getConf())) {
+      boolean useHBaseChecksum = context.getInputStreamWrapper().shouldUseHBaseChecksum();
+      FSDataInputStream stream = context.getInputStreamWrapper().getStream(useHBaseChecksum);
+      if (stream instanceof HdfsDataInputStream) {
+        this.initialReaderBlockDistribution = new InputStreamBlockDistribution((HdfsDataInputStream) stream, fileInfo);
+      }
+    }
+
     // Load up indices and fileinfo. This also loads Bloom filter type.
     metadataMap = Collections.unmodifiableMap(initialReader.loadFileInfo());
 

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

@@ -0,0 +1,91 @@
+/**
+ * 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 org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HDFSBlocksDistribution;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Computes the HDFSBlockDistribution for a file based on the underlying located blocks
+ * for an HdfsDataInputStream reading that file. This computation may involve a call to
+ * the namenode, so the value is cached based on
+ * {@link #HBASE_LOCALITY_INPUTSTREAM_DERIVE_CACHE_PERIOD}.
+ */
+@InterfaceAudience.Private
+public class InputStreamBlockDistribution {
+  private static final Logger LOG = LoggerFactory.getLogger(InputStreamBlockDistribution.class);
+
+  private static final String HBASE_LOCALITY_INPUTSTREAM_DERIVE_ENABLED =
+    "hbase.locality.inputstream.derive.enabled";
+  private static final boolean DEFAULT_HBASE_LOCALITY_INPUTSTREAM_DERIVE_ENABLED = false;
+
+  private static final String HBASE_LOCALITY_INPUTSTREAM_DERIVE_CACHE_PERIOD =
+    "hbase.locality.inputstream.derive.cache.period";
+  private static final int DEFAULT_HBASE_LOCALITY_INPUTSTREAM_DERIVE_CACHE_PERIOD = 60_000;
+
+  private final HdfsDataInputStream stream;
+  private final StoreFileInfo fileInfo;
+  private final int cachePeriodMs;
+
+  private HDFSBlocksDistribution hdfsBlocksDistribution;
+  private long lastCachedAt;
+
+  public InputStreamBlockDistribution(HdfsDataInputStream stream, StoreFileInfo fileInfo)
+    throws IOException {
+    this.stream = stream;
+    this.fileInfo = fileInfo;
+    this.cachePeriodMs = fileInfo.getConf().getInt(HBASE_LOCALITY_INPUTSTREAM_DERIVE_CACHE_PERIOD,
+      DEFAULT_HBASE_LOCALITY_INPUTSTREAM_DERIVE_CACHE_PERIOD);
+    computeBlockDistribution();
+  }
+
+  /**
+   * True if we should derive StoreFile HDFSBlockDistribution from the underlying input stream
+   */
+  public static boolean isEnabled(Configuration conf) {
+    return conf.getBoolean(HBASE_LOCALITY_INPUTSTREAM_DERIVE_ENABLED,
+      DEFAULT_HBASE_LOCALITY_INPUTSTREAM_DERIVE_ENABLED);
+  }
+
+  /**
+   * Get the HDFSBlocksDistribution derived from the StoreFile input stream, re-computing if cache
+   * is expired.
+   */
+  public synchronized HDFSBlocksDistribution getHDFSBlockDistribution() {
+    if (EnvironmentEdgeManager.currentTime() - lastCachedAt > cachePeriodMs) {
+      try {
+        LOG.debug("Refreshing HDFSBlockDistribution for {}", fileInfo);
+        computeBlockDistribution();
+      } catch (IOException e) {
+        LOG.warn("Failed to recompute block distribution for {}, falling back on last known value",
+          fileInfo, e);
+      }
+    }
+    return hdfsBlocksDistribution;
+  }
+
+  private void computeBlockDistribution() throws IOException {
+    lastCachedAt = EnvironmentEdgeManager.currentTime();
+    hdfsBlocksDistribution = FSUtils.computeHDFSBlocksDistribution(stream);
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java

@@ -81,6 +81,10 @@
 import org.apache.hadoop.hdfs.DFSHedgedReadMetrics;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.client.HdfsDataInputStream;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.util.Progressable;
@@ -703,6 +707,38 @@ public static boolean metaRegionExists(FileSystem fs, Path rootDir) throws IOExc
     return fs.exists(metaRegionDir);
   }
 
+  /**
+   * Compute HDFS block distribution of a given HdfsDataInputStream. All HdfsDataInputStreams
+   * are backed by a series of LocatedBlocks, which are fetched periodically from the namenode.
+   * This method retrieves those blocks from the input stream and uses them to calculate
+   * HDFSBlockDistribution.
+   *
+   * The underlying method in DFSInputStream does attempt to use locally cached blocks, but
+   * may hit the namenode if the cache is determined to be incomplete. The method also involves
+   * making copies of all LocatedBlocks rather than return the underlying blocks themselves.
+   */
+  static public HDFSBlocksDistribution computeHDFSBlocksDistribution(HdfsDataInputStream inputStream)
+    throws IOException {
+    List<LocatedBlock> blocks = inputStream.getAllBlocks();
+    HDFSBlocksDistribution blocksDistribution = new HDFSBlocksDistribution();
+    for (LocatedBlock block : blocks) {
+      String[] hosts = getHostsForLocations(block);
+      long len = block.getBlockSize();
+      StorageType[] storageTypes = block.getStorageTypes();
+      blocksDistribution.addHostsAndBlockWeight(hosts, len, storageTypes);
+    }
+    return blocksDistribution;
+  }
+
+  private static String[] getHostsForLocations(LocatedBlock block) {
+    DatanodeInfo[] locations = block.getLocations();
+    String[] hosts = new String[locations.length];
+    for (int i = 0; i < hosts.length; i++) {
+      hosts[i] = locations[i].getHostName();
+    }
+    return hosts;
+  }
+
   /**
    * Compute HDFS blocks distribution of a given file, or a portion of the file
    * @param fs file system