HDFS-15900. RBF: empty blockpool id on dfsrouter caused by UNAVAILABLE NameNode. (#2787)

Co-authored-by: Harunobu Daikoku <hdaikoku@yahoo-corp.jp>
(cherry picked from commit ea6595d3b6)

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/FederationNamespaceInfo.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.hdfs.server.federation.resolver;
 
+import org.apache.commons.lang3.builder.CompareToBuilder;
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.apache.hadoop.hdfs.server.federation.router.RemoteLocationContext;
 
 /**
@@ -75,4 +78,45 @@ public class FederationNamespaceInfo extends RemoteLocationContext {
   public String toString() {
     return this.nameserviceId + "->" + this.blockPoolId + ":" + this.clusterId;
   }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj == null) {
+      return false;
+    }
+    if (obj == this) {
+      return true;
+    }
+    if (obj.getClass() != getClass()) {
+      return false;
+    }
+    FederationNamespaceInfo other = (FederationNamespaceInfo) obj;
+    return new EqualsBuilder()
+        .append(nameserviceId, other.nameserviceId)
+        .append(clusterId, other.clusterId)
+        .append(blockPoolId, other.blockPoolId)
+        .isEquals();
+  }
+
+  @Override
+  public int hashCode() {
+    return new HashCodeBuilder(17, 31)
+        .append(nameserviceId)
+        .append(clusterId)
+        .append(blockPoolId)
+        .toHashCode();
+  }
+
+  @Override
+  public int compareTo(RemoteLocationContext info) {
+    if (info instanceof FederationNamespaceInfo) {
+      FederationNamespaceInfo other = (FederationNamespaceInfo) info;
+      return new CompareToBuilder()
+          .append(nameserviceId, other.nameserviceId)
+          .append(clusterId, other.clusterId)
+          .append(blockPoolId, other.blockPoolId)
+          .toComparison();
+    }
+    return super.compareTo(info);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/store/impl/MembershipStoreImpl.java

@@ -213,6 +213,8 @@ public class MembershipStoreImpl
             nnRegistrations.put(nnId, nnRegistration);
           }
           nnRegistration.add(membership);
+          if (membership.getState()
+              != FederationNamenodeServiceState.UNAVAILABLE) {
             String bpId = membership.getBlockPoolId();
             String cId = membership.getClusterId();
             String nsId = membership.getNameserviceId();
@@ -221,6 +223,7 @@ public class MembershipStoreImpl
             this.activeNamespaces.add(nsInfo);
           }
         }
+      }
 
       // Calculate most representative entry for each active NN id
       for (List<MembershipState> nnRegistration : nnRegistrations.values()) {

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/resolver/TestFederationNamespaceInfo.java

@@ -0,0 +1,39 @@
+/*
+ * 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.hdfs.server.federation.resolver;
+
+import org.junit.Test;
+
+import java.util.Set;
+import java.util.TreeSet;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TestFederationNamespaceInfo {
+  /**
+   * Regression test for HDFS-15900.
+   */
+  @Test
+  public void testHashCode() {
+    Set<FederationNamespaceInfo> set = new TreeSet<>();
+    // set an empty bpId first
+    set.add(new FederationNamespaceInfo("", "nn1", "ns1"));
+    set.add(new FederationNamespaceInfo("bp1", "nn2", "ns1"));
+    assertThat(set).hasSize(2);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/store/TestStateStoreMembershipState.java

@@ -33,12 +33,16 @@ import static org.junit.Assert.assertTrue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamenodeServiceState;
+import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamespaceInfo;
 import org.apache.hadoop.hdfs.server.federation.router.RBFConfigKeys;
 import org.apache.hadoop.hdfs.server.federation.store.protocol.GetNamenodeRegistrationsRequest;
 import org.apache.hadoop.hdfs.server.federation.store.protocol.GetNamenodeRegistrationsResponse;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetNamespaceInfoRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.GetNamespaceInfoResponse;
 import org.apache.hadoop.hdfs.server.federation.store.protocol.NamenodeHeartbeatRequest;
 import org.apache.hadoop.hdfs.server.federation.store.protocol.NamenodeHeartbeatResponse;
 import org.apache.hadoop.hdfs.server.federation.store.protocol.UpdateNamenodeRegistrationRequest;
@@ -413,6 +417,56 @@ public class TestStateStoreMembershipState extends TestStateStoreBase {
     assertEquals(FederationNamenodeServiceState.ACTIVE, quorumEntry.getState());
   }
 
+  @Test
+  public void testNamespaceInfoWithUnavailableNameNodeRegistration()
+      throws IOException {
+    // Populate the state store with one ACTIVE NameNode entry
+    // and one UNAVAILABLE NameNode entry
+    // 1) ns0:nn0 - ACTIVE
+    // 2) ns0:nn1 - UNAVAILABLE
+    List<MembershipState> registrationList = new ArrayList<>();
+    String router = ROUTERS[0];
+    String ns = NAMESERVICES[0];
+    String rpcAddress = "testrpcaddress";
+    String serviceAddress = "testserviceaddress";
+    String lifelineAddress = "testlifelineaddress";
+    String blockPoolId = "testblockpool";
+    String clusterId = "testcluster";
+    String webScheme = "http";
+    String webAddress = "testwebaddress";
+    boolean safemode = false;
+
+    MembershipState record = MembershipState.newInstance(
+        router, ns, NAMENODES[0], clusterId, blockPoolId,
+        rpcAddress, serviceAddress, lifelineAddress, webScheme,
+        webAddress, FederationNamenodeServiceState.ACTIVE, safemode);
+    registrationList.add(record);
+
+    // Set empty clusterId and blockPoolId for UNAVAILABLE NameNode
+    record = MembershipState.newInstance(
+        router, ns, NAMENODES[1], "", "",
+        rpcAddress, serviceAddress, lifelineAddress, webScheme,
+        webAddress, FederationNamenodeServiceState.UNAVAILABLE, safemode);
+    registrationList.add(record);
+
+    registerAndLoadRegistrations(registrationList);
+
+    GetNamespaceInfoRequest request = GetNamespaceInfoRequest.newInstance();
+    GetNamespaceInfoResponse response
+        = membershipStore.getNamespaceInfo(request);
+    Set<FederationNamespaceInfo> namespaces = response.getNamespaceInfo();
+
+    // Verify only one namespace is registered
+    assertEquals(1, namespaces.size());
+
+    // Verify the registered namespace has a valid pair of clusterId
+    // and blockPoolId derived from ACTIVE NameNode
+    FederationNamespaceInfo namespace = namespaces.iterator().next();
+    assertEquals(ns, namespace.getNameserviceId());
+    assertEquals(clusterId, namespace.getClusterId());
+    assertEquals(blockPoolId, namespace.getBlockPoolId());
+  }
+
   /**
    * Get a single namenode membership record from the store.
    *