HBASE-21102 - ServerCrashProcedure should select target server where no

other replicas exist for the current region (ram)

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

@@ -466,25 +466,39 @@ public class RegionStates {
   public Map<ServerName, List<RegionInfo>> getSnapShotOfAssignment(
       final Collection<RegionInfo> regions) {
     final Map<ServerName, List<RegionInfo>> result = new HashMap<ServerName, List<RegionInfo>>();
-    for (RegionInfo hri: regions) {
-      final RegionStateNode node = getRegionStateNode(hri);
-      if (node == null) continue;
-
-      // TODO: State.OPEN
-      final ServerName serverName = node.getRegionLocation();
-      if (serverName == null) continue;
-
-      List<RegionInfo> serverRegions = result.get(serverName);
-      if (serverRegions == null) {
-        serverRegions = new ArrayList<RegionInfo>();
-        result.put(serverName, serverRegions);
+    if (regions != null) {
+      for (RegionInfo hri : regions) {
+        final RegionStateNode node = getRegionStateNode(hri);
+        if (node == null) {
+          continue;
+        }
+        createSnapshot(node, result);
+      }
+    } else {
+      for (RegionStateNode node : regionsMap.values()) {
+        if (node == null) {
+          continue;
+        }
+        createSnapshot(node, result);
       }
-
-      serverRegions.add(node.getRegionInfo());
     }
     return result;
   }
 
+  private void createSnapshot(RegionStateNode node, Map<ServerName, List<RegionInfo>> result) {
+    final ServerName serverName = node.getRegionLocation();
+    if (serverName == null) {
+      return;
+    }
+
+    List<RegionInfo> serverRegions = result.get(serverName);
+    if (serverRegions == null) {
+      serverRegions = new ArrayList<RegionInfo>();
+      result.put(serverName, serverRegions);
+    }
+    serverRegions.add(node.getRegionInfo());
+  }
+
   public Map<RegionInfo, ServerName> getRegionAssignments() {
     final HashMap<RegionInfo, ServerName> assignments = new HashMap<RegionInfo, ServerName>();
     for (RegionStateNode node: regionsMap.values()) {

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

@@ -741,7 +741,6 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
       int region = regionsToIndex.get(regionInfo);
 
       int primary = regionIndexToPrimaryIndex[region];
-
       // there is a subset relation for server < host < rack
       // check server first
 
@@ -1262,7 +1261,7 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
       return assignments;
     }
 
-    Cluster cluster = createCluster(servers, regions);
+    Cluster cluster = createCluster(servers, regions, false);
     List<RegionInfo> unassignedRegions = new ArrayList<>();
 
     roundRobinAssignment(cluster, regions, unassignedRegions,
@@ -1318,12 +1317,19 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
     return assignments;
   }
 
-  protected Cluster createCluster(List<ServerName> servers, Collection<RegionInfo> regions) {
+  protected Cluster createCluster(List<ServerName> servers, Collection<RegionInfo> regions,
+      boolean hasRegionReplica) {
     // 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
     // replicas of the regions that are passed (for performance).
-    Map<ServerName, List<RegionInfo>> clusterState = getRegionAssignmentsByServer(regions);
+    Map<ServerName, List<RegionInfo>> clusterState = null;
+    if (!hasRegionReplica) {
+      clusterState = getRegionAssignmentsByServer(regions);
+    } else {
+      // for the case where we have region replica it is better we get the entire cluster's snapshot
+      clusterState = getRegionAssignmentsByServer(null);
+    }
 
     for (ServerName server : servers) {
       if (!clusterState.containsKey(server)) {
@@ -1372,7 +1378,7 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
     final List<ServerName> finalServers = idleServers.isEmpty() ?
             servers : idleServers;
     List<RegionInfo> regions = Lists.newArrayList(regionInfo);
-    Cluster cluster = createCluster(finalServers, regions);
+    Cluster cluster = createCluster(finalServers, regions, false);
     return randomAssignment(cluster, regionInfo, finalServers);
   }
 
@@ -1444,10 +1450,13 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
 
     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();
+      if (!hasRegionReplica && !RegionReplicaUtil.isDefaultReplica(region)) {
+        hasRegionReplica = true;
+      }
       List<ServerName> localServers = new ArrayList<>();
       if (oldServerName != null) {
         localServers = serversByHostname.get(oldServerName.getHostnameLowerCase());
@@ -1487,7 +1496,7 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
 
     // If servers from prior assignment aren't present, then lets do randomAssignment on regions.
     if (randomAssignRegions.size() > 0) {
-      Cluster cluster = createCluster(servers, regions.keySet());
+      Cluster cluster = createCluster(servers, regions.keySet(), hasRegionReplica);
       for (Map.Entry<ServerName, List<RegionInfo>> entry : assignments.entrySet()) {
         ServerName sn = entry.getKey();
         for (RegionInfo region : entry.getValue()) {
@@ -1497,7 +1506,6 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
       for (RegionInfo region : randomAssignRegions) {
         ServerName target = randomAssignment(cluster, region, servers);
         assignments.get(target).add(region);
-        cluster.doAssignRegion(region, target);
         numRandomAssignments++;
       }
     }
@@ -1548,12 +1556,29 @@ public abstract class BaseLoadBalancer implements LoadBalancer {
     ServerName sn = null;
     final int maxIterations = numServers * 4;
     int iterations = 0;
-
+    List<ServerName> usedSNs = new ArrayList<>(servers.size());
     do {
       int i = RANDOM.nextInt(numServers);
       sn = servers.get(i);
+      if (!usedSNs.contains(sn)) {
+        usedSNs.add(sn);
+      }
     } while (cluster.wouldLowerAvailability(regionInfo, sn)
         && iterations++ < maxIterations);
+    if (iterations >= maxIterations) {
+      // We have reached the max. Means the servers that we collected is still lowering the
+      // availability
+      for (ServerName unusedServer : servers) {
+        if (!usedSNs.contains(unusedServer)) {
+          // check if any other unused server is there for us to use.
+          // If so use it. Else we have not other go but to go with one of them
+          if (!cluster.wouldLowerAvailability(regionInfo, unusedServer)) {
+            sn = unusedServer;
+            break;
+          }
+        }
+      }
+    }
     cluster.doAssignRegion(regionInfo, sn);
     return sn;
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtility.java

@@ -1470,7 +1470,22 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    */
   public Table createTable(TableName tableName, byte[][] families, byte[][] splitKeys)
       throws IOException {
-    return createTable(tableName, families, splitKeys, new Configuration(getConfiguration()));
+    return createTable(tableName, families, splitKeys, 1, new Configuration(getConfiguration()));
+  }
+
+  /**
+   * Create a table.
+   * @param tableName the table name
+   * @param families the families
+   * @param splitKeys the splitkeys
+   * @param replicaCount the region replica count
+   * @return A Table instance for the created table.
+   * @throws IOException throws IOException
+   */
+  public Table createTable(TableName tableName, byte[][] families, byte[][] splitKeys,
+      int replicaCount) throws IOException {
+    return createTable(tableName, families, splitKeys, replicaCount,
+      new Configuration(getConfiguration()));
   }
 
   public Table createTable(TableName tableName, byte[][] families,
@@ -1561,16 +1576,19 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
 
   /**
    * Create a table.
-   * @param tableName
-   * @param families
-   * @param splitKeys
+   * @param tableName the table name
+   * @param families the families
+   * @param splitKeys the split keys
+   * @param replicaCount the replica count
    * @param c Configuration to use
    * @return A Table instance for the created table.
    * @throws IOException
    */
   public Table createTable(TableName tableName, byte[][] families, byte[][] splitKeys,
-      final Configuration c) throws IOException {
-    return createTable(new HTableDescriptor(tableName), families, splitKeys, c);
+      int replicaCount, final Configuration c) throws IOException {
+    HTableDescriptor htd = new HTableDescriptor(tableName);
+    htd.setRegionReplication(replicaCount);
+    return createTable(htd, families, splitKeys, c);
   }
 
   /**

hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedure.java

@@ -20,6 +20,8 @@ package org.apache.hadoop.hbase.master.procedure;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.io.IOException;
+
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
@@ -52,7 +54,7 @@ public class TestServerCrashProcedure {
 
   private static final Logger LOG = LoggerFactory.getLogger(TestServerCrashProcedure.class);
 
-  private HBaseTestingUtility util;
+  protected HBaseTestingUtility util;
 
   private ProcedureMetrics serverCrashProcMetrics;
   private long serverCrashSubmittedCount = 0;
@@ -68,13 +70,17 @@ public class TestServerCrashProcedure {
   public void setup() throws Exception {
     this.util = new HBaseTestingUtility();
     setupConf(this.util.getConfiguration());
-    this.util.startMiniCluster(3);
+    startMiniCluster();
     ProcedureTestingUtility.setKillAndToggleBeforeStoreUpdate(
       this.util.getHBaseCluster().getMaster().getMasterProcedureExecutor(), false);
     serverCrashProcMetrics = this.util.getHBaseCluster().getMaster().getMasterMetrics()
         .getServerCrashProcMetrics();
   }
 
+  protected void startMiniCluster() throws Exception {
+    this.util.startMiniCluster(3);
+  }
+
   @After
   public void tearDown() throws Exception {
     MiniHBaseCluster cluster = this.util.getHBaseCluster();
@@ -113,11 +119,9 @@ public class TestServerCrashProcedure {
    */
   private void testRecoveryAndDoubleExecution(boolean carryingMeta, boolean doubleExecution)
       throws Exception {
-    final TableName tableName = TableName.valueOf(
-      "testRecoveryAndDoubleExecution-carryingMeta-" + carryingMeta);
-    final Table t = this.util.createTable(tableName, HBaseTestingUtility.COLUMNS,
-        HBaseTestingUtility.KEYS_FOR_HBA_CREATE_TABLE);
-    try {
+    final TableName tableName = TableName.valueOf("testRecoveryAndDoubleExecution-carryingMeta-"
+        + carryingMeta + "-doubleExecution-" + doubleExecution);
+    try (Table t = createTable(tableName)) {
       // Load the table with a bit of data so some logs to split and some edits in each region.
       this.util.loadTable(t, HBaseTestingUtility.COLUMNS[0]);
       final int count = util.countRows(t);
@@ -155,17 +159,25 @@ public class TestServerCrashProcedure {
         long procId = getSCPProcId(procExec);
         ProcedureTestingUtility.waitProcedure(procExec, procId);
       }
-      // Assert all data came back.
+      assertReplicaDistributed(t);
       assertEquals(count, util.countRows(t));
       assertEquals(checksum, util.checksumRows(t));
-    } catch(Throwable throwable) {
+    } catch (Throwable throwable) {
       LOG.error("Test failed!", throwable);
       throw throwable;
-    } finally {
-      t.close();
     }
   }
 
+  protected void assertReplicaDistributed(final Table t) {
+    return;
+  }
+
+  protected Table createTable(final TableName tableName) throws IOException {
+    final Table t = this.util.createTable(tableName, HBaseTestingUtility.COLUMNS,
+        HBaseTestingUtility.KEYS_FOR_HBA_CREATE_TABLE);
+    return t;
+  }
+
   private void collectMasterMetrics() {
     serverCrashSubmittedCount = serverCrashProcMetrics.getSubmittedCounter().getCount();
     serverCrashFailedCount = serverCrashProcMetrics.getFailedCounter().getCount();

hbase-server/src/test/java/org/apache/hadoop/hbase/master/procedure/TestServerCrashProcedureWithReplicas.java

@@ -0,0 +1,84 @@
+/**
+ * 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.master.procedure;
+
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+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.client.Table;
+import org.apache.hadoop.hbase.regionserver.Region;
+import org.apache.hadoop.hbase.testclassification.LargeTests;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
+import org.junit.ClassRule;
+import org.junit.experimental.categories.Category;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Category({ MasterTests.class, LargeTests.class })
+public class TestServerCrashProcedureWithReplicas extends TestServerCrashProcedure {
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+      HBaseClassTestRule.forClass(TestServerCrashProcedureWithReplicas.class);
+  private static final Logger LOG =
+      LoggerFactory.getLogger(TestServerCrashProcedureWithReplicas.class);
+
+  @Override
+  protected void startMiniCluster() throws Exception {
+    // Start a cluster with 4 nodes because we have 3 replicas.
+    // So on a crash of a server still we can ensure that the
+    // replicas are distributed.
+    this.util.startMiniCluster(4);
+  }
+
+  @Override
+  protected Table createTable(final TableName tableName) throws IOException {
+    final Table t = this.util.createTable(tableName, HBaseTestingUtility.COLUMNS,
+      HBaseTestingUtility.KEYS_FOR_HBA_CREATE_TABLE, 3);
+    return t;
+  }
+
+  protected void assertReplicaDistributed(final Table t) {
+    // Assert all data came back.
+    List<RegionInfo> regionInfos = new ArrayList<>();
+    for (RegionServerThread rs : this.util.getMiniHBaseCluster().getRegionServerThreads()) {
+      regionInfos.clear();
+      for (Region r : rs.getRegionServer().getRegions(t.getName())) {
+        LOG.info("The region is " + r.getRegionInfo() + " the location is "
+            + rs.getRegionServer().getServerName());
+        if (contains(regionInfos, r.getRegionInfo())) {
+          LOG.error("Am exiting");
+          fail("Crashed replica regions should not be assigned to same region server");
+        } else {
+          regionInfos.add(r.getRegionInfo());
+        }
+      }
+    }
+  }
+
+  private boolean contains(List<RegionInfo> regionInfos, RegionInfo regionInfo) {
+    for (RegionInfo info : regionInfos) {
+      if (RegionReplicaUtil.isReplicasForSameRegion(info, regionInfo)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}