HDFS-9001. DFSUtil.getNsServiceRpcUris() can return too many entries in a non-HA, non-federated cluster. Contributed by Daniel Templeton.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -1468,6 +1468,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9174. Fix findbugs warnings in FSOutputSummer.tracer and
     DirectoryScanner$ReportCompiler.currentThread. (Yi Liu via wheat9)
 
+    HDFS-9001. DFSUtil.getNsServiceRpcUris() can return too many entries in a
+    non-HA, non-federated cluster. (Daniel Templeton via atm)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java

@@ -733,8 +733,15 @@ public class DFSUtil {
       }
     }
 
-    // Add the default URI if it is an HDFS URI.
+    // Add the default URI if it is an HDFS URI and we haven't come up with a
+    // valid non-nameservice NN address yet.  Consider the servicerpc-address
+    // and rpc-address to be the "unnamed" nameservice.  defaultFS is our
+    // fallback when rpc-address isn't given.  We therefore only want to add
+    // the defaultFS when neither the servicerpc-address (which is preferred)
+    // nor the rpc-address (which overrides defaultFS) is given.
+    if (!uriFound) {
       URI defaultUri = FileSystem.getDefaultUri(conf);
+
       // checks if defaultUri is ip:port format
       // and convert it to hostname:port format
       if (defaultUri != null && (defaultUri.getPort() != -1)) {
@@ -742,11 +749,13 @@ public class DFSUtil {
             NetUtils.createSocketAddr(defaultUri.getHost(),
                 defaultUri.getPort()));
       }
+
       if (defaultUri != null &&
           HdfsConstants.HDFS_URI_SCHEME.equals(defaultUri.getScheme()) &&
           !nonPreferredUris.contains(defaultUri)) {
         ret.add(defaultUri);
       }
+    }
     
     return ret;
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java

@@ -616,6 +616,11 @@ public class TestDFSUtil {
         DFSUtil.substituteForWildcardAddress("127.0.0.1:12345", "foo"));
   }
   
+  /**
+   * Test how name service URIs are handled with a variety of configuration
+   * settings
+   * @throws Exception
+   */
   @Test
   public void testGetNNUris() throws Exception {
     HdfsConfiguration conf = new HdfsConfiguration();
@@ -627,67 +632,126 @@ public class TestDFSUtil {
     final String NN1_SRVC_ADDR  = "nn.example.com:8021";
     final String NN2_ADDR       = "nn2.example.com:8020";
 
+    conf.set(DFS_NAMESERVICES, "ns1");
+    conf.set(DFSUtil.addKeySuffixes(
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, "ns1"), NS1_NN1_ADDR);
+
+    conf.set(DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, "hdfs://" + NN2_ADDR);
+    conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY, "hdfs://" + NN1_ADDR);
+
+    Collection<URI> uris = DFSUtil.getNameServiceUris(conf,
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY,  DFS_NAMENODE_RPC_ADDRESS_KEY);
+
+    assertEquals("Incorrect number of URIs returned", 2, uris.size());
+    assertTrue("Missing URI for name service ns1",
+        uris.contains(new URI("hdfs://" + NS1_NN1_ADDR)));
+    assertTrue("Missing URI for service address",
+        uris.contains(new URI("hdfs://" + NN2_ADDR)));
+
+    conf = new HdfsConfiguration();
     conf.set(DFS_NAMESERVICES, "ns1,ns2");
-    conf.set(DFSUtil.addKeySuffixes(DFS_HA_NAMENODES_KEY_PREFIX, "ns1"),"nn1,nn2");
+    conf.set(DFSUtil.addKeySuffixes(DFS_HA_NAMENODES_KEY_PREFIX, "ns1"),
+        "nn1,nn2");
     conf.set(DFSUtil.addKeySuffixes(
         DFS_NAMENODE_RPC_ADDRESS_KEY, "ns1", "nn1"), NS1_NN1_ADDR);
     conf.set(DFSUtil.addKeySuffixes(
         DFS_NAMENODE_RPC_ADDRESS_KEY, "ns1", "nn2"), NS1_NN2_ADDR);
 
-    conf.set(DFSUtil.addKeySuffixes(DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, "ns2"),
+    conf.set(DFSUtil.addKeySuffixes(
-        NS2_NN_ADDR);
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, "ns2"), NS2_NN_ADDR);
 
     conf.set(DFS_NAMENODE_RPC_ADDRESS_KEY, "hdfs://" + NN1_ADDR);
 
     conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY, "hdfs://" + NN2_ADDR);
 
-    Collection<URI> uris = DFSUtil.getNameServiceUris(conf,
+    uris = DFSUtil.getNameServiceUris(conf,
         DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY,  DFS_NAMENODE_RPC_ADDRESS_KEY);
 
-    assertEquals(4, uris.size());
+    assertEquals("Incorrect number of URIs returned", 3, uris.size());
-    assertTrue(uris.contains(new URI("hdfs://ns1")));
+    assertTrue("Missing URI for name service ns1",
-    assertTrue(uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+        uris.contains(new URI("hdfs://ns1")));
-    assertTrue(uris.contains(new URI("hdfs://" + NN1_ADDR)));
+    assertTrue("Missing URI for name service ns2",
-    assertTrue(uris.contains(new URI("hdfs://" + NN2_ADDR)));
+        uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+    assertTrue("Missing URI for RPC address",
+        uris.contains(new URI("hdfs://" + NN1_ADDR)));
 
     // Make sure that non-HDFS URIs in fs.defaultFS don't get included.
     conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY,
         "viewfs://vfs-name.example.com");
 
-    uris = DFSUtil.getNameServiceUris(conf, DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, 
+    uris = DFSUtil.getNameServiceUris(conf,
-        DFS_NAMENODE_RPC_ADDRESS_KEY);
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
 
-    assertEquals(3, uris.size());
+    assertEquals("Incorrect number of URIs returned", 3, uris.size());
-    assertTrue(uris.contains(new URI("hdfs://ns1")));
+    assertTrue("Missing URI for name service ns1",
-    assertTrue(uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+        uris.contains(new URI("hdfs://ns1")));
-    assertTrue(uris.contains(new URI("hdfs://" + NN1_ADDR)));
+    assertTrue("Missing URI for name service ns2",
+        uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+    assertTrue("Missing URI for RPC address",
+        uris.contains(new URI("hdfs://" + NN1_ADDR)));
 
     // Make sure that an HA URI being the default URI doesn't result in multiple
     // entries being returned.
     conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY, "hdfs://ns1");
     
-    uris = DFSUtil.getNameServiceUris(conf, DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, 
+    uris = DFSUtil.getNameServiceUris(conf,
-        DFS_NAMENODE_RPC_ADDRESS_KEY);
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
 
-    assertEquals(3, uris.size());
+    assertEquals("Incorrect number of URIs returned", 3, uris.size());
-    assertTrue(uris.contains(new URI("hdfs://ns1")));
+    assertTrue("Missing URI for name service ns1",
-    assertTrue(uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+        uris.contains(new URI("hdfs://ns1")));
-    assertTrue(uris.contains(new URI("hdfs://" + NN1_ADDR)));
+    assertTrue("Missing URI for name service ns2",
+        uris.contains(new URI("hdfs://" + NS2_NN_ADDR)));
+    assertTrue("Missing URI for RPC address",
+        uris.contains(new URI("hdfs://" + NN1_ADDR)));
+
+    // Check that the default URI is returned if there's nothing else to return.
+    conf = new HdfsConfiguration();
+    conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY, "hdfs://" + NN1_ADDR);
+
+    uris = DFSUtil.getNameServiceUris(conf,
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
+
+    assertEquals("Incorrect number of URIs returned", 1, uris.size());
+    assertTrue("Missing URI for RPC address (defaultFS)",
+        uris.contains(new URI("hdfs://" + NN1_ADDR)));
+
+    // Check that the RPC address is the only address returned when the RPC
+    // and the default FS is given.
+    conf.set(DFS_NAMENODE_RPC_ADDRESS_KEY, NN2_ADDR);
+
+    uris = DFSUtil.getNameServiceUris(conf,
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
+
+    assertEquals("Incorrect number of URIs returned", 1, uris.size());
+    assertTrue("Missing URI for RPC address",
+        uris.contains(new URI("hdfs://" + NN2_ADDR)));
 
     // Make sure that when a service RPC address is used that is distinct from
     // the client RPC address, and that client RPC address is also used as the
     // default URI, that the client URI does not end up in the set of URIs
     // returned.
+    conf.set(DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, NN1_ADDR);
+
+    uris = DFSUtil.getNameServiceUris(conf,
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
+
+    assertEquals("Incorrect number of URIs returned", 1, uris.size());
+    assertTrue("Missing URI for service ns1",
+        uris.contains(new URI("hdfs://" + NN1_ADDR)));
+
+    // Check that when the default FS and service address are given, but
+    // the RPC address isn't, that only the service address is returned.
     conf = new HdfsConfiguration();
     conf.set(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY, "hdfs://" + NN1_ADDR);
-    conf.set(DFS_NAMENODE_RPC_ADDRESS_KEY, NN1_ADDR);
     conf.set(DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, NN1_SRVC_ADDR);
     
-    uris = DFSUtil.getNameServiceUris(conf, DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, 
+    uris = DFSUtil.getNameServiceUris(conf,
-        DFS_NAMENODE_RPC_ADDRESS_KEY);
+        DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY, DFS_NAMENODE_RPC_ADDRESS_KEY);
 
-    assertEquals(1, uris.size());
+    assertEquals("Incorrect number of URIs returned", 1, uris.size());
-    assertTrue(uris.contains(new URI("hdfs://" + NN1_SRVC_ADDR)));
+    assertTrue("Missing URI for service address",
+        uris.contains(new URI("hdfs://" + NN1_SRVC_ADDR)));
   }
 
   @Test (timeout=15000)