HBASE-23078 BaseLoadBalancer should consider region replicas when randomAssignment and roundRobinAssignment

Author: infraio

hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStates.java

@@ -37,11 +37,9 @@
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RegionInfo;
-import org.apache.hadoop.hbase.client.RegionReplicaUtil;
 import org.apache.hadoop.hbase.master.RegionState;
 import org.apache.hadoop.hbase.master.RegionState.State;
 import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.ServerRegionReplicaUtil;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -746,26 +744,6 @@ public ServerStateNode addRegionToServer(final RegionStateNode regionNode) {
     return serverNode;
   }
 
-  public boolean isReplicaAvailableForRegion(final RegionInfo info) {
-    // if the region info itself is a replica return true.
-    if (!RegionReplicaUtil.isDefaultReplica(info)) {
-      return true;
-    }
-    // iterate the regionsMap for the given region name. If there are replicas it should
-    // list them in order.
-    for (RegionStateNode node : regionsMap.tailMap(info.getRegionName()).values()) {
-      if (!node.getTable().equals(info.getTable())
-          || !ServerRegionReplicaUtil.isReplicasForSameRegion(info, node.getRegionInfo())) {
-        break;
-      } else if (!RegionReplicaUtil.isDefaultReplica(node.getRegionInfo())) {
-        // we have replicas
-        return true;
-      }
-    }
-    // we don have replicas
-    return false;
-  }
-
   public ServerStateNode removeRegionFromServer(final ServerName serverName,
       final RegionStateNode regionNode) {
     ServerStateNode serverNode = getOrCreateServer(serverName);

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

@@ -18,6 +18,7 @@
  */
 package org.apache.hadoop.hbase.master.balancer;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -52,8 +53,6 @@
 import org.apache.hadoop.hbase.master.MasterServices;
 import org.apache.hadoop.hbase.master.RackManager;
 import org.apache.hadoop.hbase.master.RegionPlan;
-import org.apache.hadoop.hbase.master.assignment.AssignmentManager;
-import org.apache.hadoop.hbase.master.assignment.RegionStates;
 import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.Action.Type;
 import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
 import org.apache.hbase.thirdparty.com.google.common.base.Joiner;
@@ -1263,7 +1262,7 @@ public Map<ServerName, List<RegionInfo>> roundRobinAssignment(List<RegionInfo> r
       return assignments;
     }
 
-    Cluster cluster = createCluster(servers, regions, false);
+    Cluster cluster = createCluster(servers, regions);
     List<RegionInfo> unassignedRegions = new ArrayList<>();
 
     roundRobinAssignment(cluster, regions, unassignedRegions,
@@ -1319,8 +1318,22 @@ public Map<ServerName, List<RegionInfo>> roundRobinAssignment(List<RegionInfo> r
     return assignments;
   }
 
-  protected Cluster createCluster(List<ServerName> servers, Collection<RegionInfo> regions,
-      boolean hasRegionReplica) {
+  protected Cluster createCluster(List<ServerName> servers, Collection<RegionInfo> regions)
+      throws HBaseIOException {
+    boolean hasRegionReplica = false;
+    try {
+      for (RegionInfo regionInfo : regions) {
+        TableName tableName = regionInfo.getTable();
+        if (services != null &&
+            services.getTableDescriptors().get(tableName).getRegionReplication() > 1) {
+          hasRegionReplica = true;
+          break;
+        }
+      }
+    } catch (IOException ioe) {
+      throw new HBaseIOException(ioe);
+    }
+
     // Get the snapshot of the current assignments for the regions in question, and then create
     // a cluster out of it. Note that we might have replicas already assigned to some servers
     // earlier. So we want to get the snapshot to see those assignments, but this will only contain
@@ -1380,7 +1393,7 @@ public ServerName randomAssignment(RegionInfo regionInfo, List<ServerName> serve
     final List<ServerName> finalServers = idleServers.isEmpty() ?
             servers : idleServers;
     List<RegionInfo> regions = Lists.newArrayList(regionInfo);
-    Cluster cluster = createCluster(finalServers, regions, false);
+    Cluster cluster = createCluster(finalServers, regions);
     return randomAssignment(cluster, regionInfo, finalServers);
   }
 
@@ -1452,21 +1465,9 @@ public Map<ServerName, List<RegionInfo>> retainAssignment(Map<RegionInfo, Server
 
     int numRandomAssignments = 0;
     int numRetainedAssigments = 0;
-    boolean hasRegionReplica = false;
     for (Map.Entry<RegionInfo, ServerName> entry : regions.entrySet()) {
       RegionInfo region = entry.getKey();
       ServerName oldServerName = entry.getValue();
-      // In the current set of regions even if one has region replica let us go with
-      // getting the entire snapshot
-      if (this.services != null) { // for tests
-        AssignmentManager am = this.services.getAssignmentManager();
-        if (am != null) {
-          RegionStates states = am.getRegionStates();
-          if (!hasRegionReplica && states != null && states.isReplicaAvailableForRegion(region)) {
-            hasRegionReplica = true;
-          }
-        }
-      }
       List<ServerName> localServers = new ArrayList<>();
       if (oldServerName != null) {
         localServers = serversByHostname.get(oldServerName.getHostnameLowerCase());
@@ -1506,7 +1507,7 @@ public Map<ServerName, List<RegionInfo>> retainAssignment(Map<RegionInfo, Server
 
     // If servers from prior assignment aren't present, then lets do randomAssignment on regions.
     if (randomAssignRegions.size() > 0) {
-      Cluster cluster = createCluster(servers, regions.keySet(), hasRegionReplica);
+      Cluster cluster = createCluster(servers, regions.keySet());
       for (Map.Entry<ServerName, List<RegionInfo>> entry : assignments.entrySet()) {
         ServerName sn = entry.getKey();
         for (RegionInfo region : entry.getValue()) {

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestRegionReplicasWithRestartScenarios.java

@@ -24,10 +24,12 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
+
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionReplicaUtil;
@@ -37,7 +39,6 @@
 import org.apache.hadoop.hbase.testclassification.RegionServerTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.RegionSplitter;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -64,31 +65,27 @@ public class TestRegionReplicasWithRestartScenarios {
 
   private static final int NB_SERVERS = 3;
   private Table table;
+  private TableName tableName;
 
   private static final HBaseTestingUtility HTU = new HBaseTestingUtility();
   private static final byte[] f = HConstants.CATALOG_FAMILY;
 
   @BeforeClass
   public static void beforeClass() throws Exception {
-    // Reduce the hdfs block size and prefetch to trigger the file-link reopen
-    // when the file is moved to archive (e.g. compaction)
-    HTU.getConfiguration().setInt(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, 8192);
-    HTU.getConfiguration().setInt(DFSConfigKeys.DFS_CLIENT_READ_PREFETCH_SIZE_KEY, 1);
-    HTU.getConfiguration().setInt(HConstants.HREGION_MEMSTORE_FLUSH_SIZE, 128 * 1024 * 1024);
-    HTU.getConfiguration().setInt(">hbase.master.wait.on.regionservers.mintostart", 3);
+    HTU.getConfiguration().setInt("hbase.master.wait.on.regionservers.mintostart", NB_SERVERS);
     HTU.startMiniCluster(NB_SERVERS);
   }
 
   @Before
   public void before() throws IOException {
-    TableName tableName = TableName.valueOf(this.name.getMethodName());
-    // Create table then get the single region for our new table.
-    this.table = createTableDirectlyFromHTD(tableName);
+    this.tableName = TableName.valueOf(this.name.getMethodName());
+    this.table = createTableDirectlyFromHTD(this.tableName);
   }
 
   @After
   public void after() throws IOException {
     this.table.close();
+    HTU.deleteTable(this.tableName);
   }
 
   private static Table createTableDirectlyFromHTD(final TableName tableName) throws IOException {
@@ -125,6 +122,20 @@ private HRegionServer getTertiaryRS() {
 
   @Test
   public void testRegionReplicasCreated() throws Exception {
+    assertReplicaDistributed();
+  }
+
+  @Test
+  public void testWhenRestart() throws Exception {
+    ServerName serverName = getRS().getServerName();
+    HTU.getHBaseCluster().stopRegionServer(serverName);
+    HTU.getHBaseCluster().waitForRegionServerToStop(serverName, 60000);
+    HTU.getHBaseCluster().startRegionServerAndWait(60000);
+    HTU.waitTableAvailable(this.tableName);
+    assertReplicaDistributed();
+  }
+
+  private void assertReplicaDistributed() throws Exception {
     Collection<HRegion> onlineRegions = getRS().getOnlineRegionsLocalContext();
     boolean res = checkDuplicates(onlineRegions);
     assertFalse(res);
@@ -150,7 +161,7 @@ private boolean checkDuplicates(Collection<HRegion> onlineRegions3) throws Excep
           RegionReplicaUtil.getRegionInfoForDefaultReplica(actualRegion.getRegionInfo()))) {
           i++;
           if (i > 1) {
-            LOG.info("Duplicate found " + actualRegion.getRegionInfo() + " " +
+            LOG.warn("Duplicate found {} and {}", actualRegion.getRegionInfo(),
                 region.getRegionInfo());
             assertTrue(Bytes.equals(region.getRegionInfo().getStartKey(),
               actualRegion.getRegionInfo().getStartKey()));