HDFS-5279. Guard against NullPointerException in NameNode JSP pages before initialization of FSNamesystem. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1528308 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -385,6 +385,9 @@ Release 2.1.2 - UNRELEASED
     HDFS-5255. Distcp job fails with hsftp when https is enabled in insecure
     cluster. (Arpit Agarwal)
 
+    HDFS-5279. Guard against NullPointerException in NameNode JSP pages before
+    initialization of FSNamesystem. (cnauroth)
+
 Release 2.1.1-beta - 2013-09-23
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NamenodeJspHelper.java

@@ -30,6 +30,7 @@ import java.net.URLEncoder;
 import java.security.PrivilegedExceptionAction;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.Iterator;
 import java.util.List;
@@ -210,6 +211,9 @@ class NamenodeJspHelper {
 
   static void generateSnapshotReport(JspWriter out, FSNamesystem fsn)
       throws IOException {
+    if (fsn == null) {
+      return;
+    }
     out.println("<div id=\"snapshotstats\"><div class=\"dfstable\">"
         + "<table class=\"storage\" title=\"Snapshot Summary\">\n"
         + "<thead><tr><td><b>Snapshottable directories</b></td>"
@@ -652,7 +656,8 @@ class NamenodeJspHelper {
         .getAttribute(JspHelper.CURRENT_CONF);
     // We can't redirect if there isn't a DN to redirect to.
     // Lets instead show a proper error message.
-    if (nn.getNamesystem().getNumLiveDataNodes() < 1) {
+    FSNamesystem fsn = nn.getNamesystem();
+    if (fsn == null || fsn.getNumLiveDataNodes() < 1) {
       throw new IOException("Can't browse the DFS since there are no " +
           "live nodes available to redirect to.");
     }
@@ -688,6 +693,20 @@ class NamenodeJspHelper {
     resp.sendRedirect(redirectLocation);
   }
 
+  /**
+   * Returns a descriptive label for the running NameNode.  If the NameNode has
+   * initialized to the point of running its RPC server, then this label consists
+   * of the host and port of the RPC server.  Otherwise, the label is a message
+   * stating that the NameNode is still initializing.
+   * 
+   * @param nn NameNode to describe
+   * @return String NameNode label
+   */
+  static String getNameNodeLabel(NameNode nn) {
+    return nn.getRpcServer() != null ? nn.getNameNodeAddressHostPortString() :
+      "initializing";
+  }
+
   static class NodeListJsp {
     private int rowNum = 0;
 
@@ -843,6 +862,9 @@ class NamenodeJspHelper {
         HttpServletRequest request) throws IOException {
       final NameNode nn = NameNodeHttpServer.getNameNodeFromContext(context);
       final FSNamesystem ns = nn.getNamesystem();
+      if (ns == null) {
+        return;
+      }
       final DatanodeManager dm = ns.getBlockManager().getDatanodeManager();
 
       final List<DatanodeDescriptor> live = new ArrayList<DatanodeDescriptor>();
@@ -1022,14 +1044,16 @@ class NamenodeJspHelper {
     final BlockManager blockManager;
     
     XMLBlockInfo(FSNamesystem fsn, Long blockId) {
-      this.blockManager = fsn.getBlockManager();
+      this.blockManager = fsn != null ? fsn.getBlockManager() : null;
 
       if (blockId == null) {
         this.block = null;
         this.inode = null;
       } else {
         this.block = new Block(blockId);
-        this.inode = ((INode)blockManager.getBlockCollection(block)).asFile();
+        this.inode = blockManager != null ?
+          ((INode)blockManager.getBlockCollection(block)).asFile() :
+          null;
       }
     }
 
@@ -1103,8 +1127,10 @@ class NamenodeJspHelper {
         } 
 
         doc.startTag("replicas");
-        for(final Iterator<DatanodeDescriptor> it = blockManager.datanodeIterator(block);
-            it.hasNext(); ) {
+        for (final Iterator<DatanodeDescriptor> it = blockManager != null ?
+            blockManager.datanodeIterator(block) :
+            Collections.<DatanodeDescriptor>emptyList().iterator();
+            it.hasNext();) {
           doc.startTag("replica");
 
           DatanodeDescriptor dd = it.next();
@@ -1140,7 +1166,7 @@ class NamenodeJspHelper {
     
     XMLCorruptBlockInfo(FSNamesystem fsn, Configuration conf,
                                int numCorruptBlocks, Long startingBlockId) {
-      this.blockManager = fsn.getBlockManager();
+      this.blockManager = fsn != null ? fsn.getBlockManager() : null;
       this.conf = conf;
       this.numCorruptBlocks = numCorruptBlocks;
       this.startingBlockId = startingBlockId;
@@ -1163,16 +1189,19 @@ class NamenodeJspHelper {
       doc.endTag();
       
       doc.startTag("num_missing_blocks");
-      doc.pcdata(""+blockManager.getMissingBlocksCount());
+      doc.pcdata("" + (blockManager != null ?
+        blockManager.getMissingBlocksCount() : 0));
       doc.endTag();
       
       doc.startTag("num_corrupt_replica_blocks");
-      doc.pcdata(""+blockManager.getCorruptReplicaBlocksCount());
+      doc.pcdata("" + (blockManager != null ?
+        blockManager.getCorruptReplicaBlocksCount() : 0));
       doc.endTag();
      
       doc.startTag("corrupt_replica_block_ids");
-      final long[] corruptBlockIds = blockManager.getCorruptReplicaBlockIds(
-          numCorruptBlocks, startingBlockId);
+      final long[] corruptBlockIds = blockManager != null ?
+        blockManager.getCorruptReplicaBlockIds(numCorruptBlocks,
+        startingBlockId) : null;
       if (corruptBlockIds != null) {
         for (Long blockId: corruptBlockIds) {
           doc.startTag("block_id");

hadoop-hdfs-project/hadoop-hdfs/src/main/webapps/hdfs/corrupt_files.jsp

@@ -25,6 +25,7 @@
 	import="org.apache.hadoop.fs.Path"
 	import="org.apache.hadoop.ha.HAServiceProtocol.HAServiceState"
 	import="java.util.Collection"
+	import="java.util.Collections"
 	import="java.util.Arrays" %>
 <%!//for java.io.Serializable
   private static final long serialVersionUID = 1L;%>
@@ -34,9 +35,10 @@
   HAServiceState nnHAState = nn.getServiceState();
   boolean isActive = (nnHAState == HAServiceState.ACTIVE);
   String namenodeRole = nn.getRole().toString();
-  String namenodeLabel = nn.getNameNodeAddressHostPortString();
-  Collection<FSNamesystem.CorruptFileBlockInfo> corruptFileBlocks = 
-	fsn.listCorruptFileBlocks("/", null);
+  String namenodeLabel = NamenodeJspHelper.getNameNodeLabel(nn);
+  Collection<FSNamesystem.CorruptFileBlockInfo> corruptFileBlocks = fsn != null ?
+    fsn.listCorruptFileBlocks("/", null) :
+    Collections.<FSNamesystem.CorruptFileBlockInfo>emptyList();
   int corruptFileCount = corruptFileBlocks.size();
 %>
 
@@ -48,7 +50,7 @@
 <h1><%=namenodeRole%> '<%=namenodeLabel%>'</h1>
 <%=NamenodeJspHelper.getVersionTable(fsn)%>
 <br>
-<% if (isActive) { %> 
+<% if (isActive && fsn != null) { %> 
   <b><a href="/nn_browsedfscontent.jsp">Browse the filesystem</a></b>
   <br>
 <% } %> 

hadoop-hdfs-project/hadoop-hdfs/src/main/webapps/hdfs/dfshealth.jsp

@@ -34,29 +34,20 @@
   boolean isActive = (nnHAState == HAServiceState.ACTIVE);
   String namenodeRole = nn.getRole().toString();
   String namenodeState = nnHAState.toString();
-  String namenodeLabel = nn.getRpcServer() != null ?
-    nn.getNameNodeAddressHostPortString() : null;
+  String namenodeLabel = NamenodeJspHelper.getNameNodeLabel(nn);
 %>
 
 <!DOCTYPE html>
 <html>
 <head>
 <link rel="stylesheet" type="text/css" href="/static/hadoop.css">
-<% if (namenodeLabel != null) { %>
 <title>Hadoop <%=namenodeRole%>&nbsp;<%=namenodeLabel%></title>
-<% } else { %>
-<title>Hadoop <%=namenodeRole%></title>
-<% } %>
 </head>    
 <body>
-<% if (namenodeLabel != null) { %>
 <h1><%=namenodeRole%> '<%=namenodeLabel%>' (<%=namenodeState%>)</h1>
-<% } else { %>
-<h1><%=namenodeRole%> (<%=namenodeState%>)</h1>
-<% } %>
 <%= NamenodeJspHelper.getVersionTable(fsn) %>
 <br />
-<% if (isActive) { %> 
+<% if (isActive && fsn != null) { %> 
   <b><a href="/nn_browsedfscontent.jsp">Browse the filesystem</a></b><br>
 <% } %> 
 <b><a href="/logs/"><%=namenodeRole%> Logs</a></b>

hadoop-hdfs-project/hadoop-hdfs/src/main/webapps/hdfs/dfsnodelist.jsp

@@ -33,7 +33,7 @@ String namenodeRole = nn.getRole().toString();
 FSNamesystem fsn = nn.getNamesystem();
 HAServiceState nnHAState = nn.getServiceState();
 boolean isActive = (nnHAState == HAServiceState.ACTIVE);
-String namenodeLabel = nn.getNameNodeAddressHostPortString();
+String namenodeLabel = NamenodeJspHelper.getNameNodeLabel(nn);
 %>
 
 <!DOCTYPE html>
@@ -46,7 +46,7 @@ String namenodeLabel = nn.getNameNodeAddressHostPortString();
 <h1><%=namenodeRole%> '<%=namenodeLabel%>'</h1>
 <%= NamenodeJspHelper.getVersionTable(fsn) %>
 <br />
-<% if (isActive) { %> 
+<% if (isActive && fsn != null) { %> 
   <b><a href="/nn_browsedfscontent.jsp">Browse the filesystem</a></b><br>
 <% } %> 
 <b><a href="/logs/"><%=namenodeRole%> Logs</a></b><br>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeJspHelper.java

@@ -25,12 +25,15 @@ import static org.apache.hadoop.hdfs.server.namenode.startupprogress.Phase.SAVIN
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 import java.io.IOException;
 import java.util.List;
 import java.util.regex.Pattern;
 
+import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import javax.servlet.jsp.JspWriter;
 
 import org.apache.hadoop.conf.Configuration;
@@ -45,6 +48,7 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
+import org.znerd.xmlenc.XMLOutputter;
 
 public class TestNameNodeJspHelper {
 
@@ -117,6 +121,75 @@ public class TestNameNodeJspHelper {
     Assert.assertEquals("", NamenodeJspHelper.getRollingUpgradeText(null));
   }
 
+  /**
+   * Tests for non-null, non-empty NameNode label.
+   */
+  @Test
+  public void testGetNameNodeLabel() {
+    String nameNodeLabel = NamenodeJspHelper.getNameNodeLabel(
+      cluster.getNameNode());
+    Assert.assertNotNull(nameNodeLabel);
+    Assert.assertFalse(nameNodeLabel.isEmpty());
+  }
+
+  /**
+   * Tests for non-null, non-empty NameNode label when called before
+   * initialization of the NameNode RPC server.
+   */
+  @Test
+  public void testGetNameNodeLabelNullRpcServer() {
+    NameNode nn = mock(NameNode.class);
+    when(nn.getRpcServer()).thenReturn(null);
+    String nameNodeLabel = NamenodeJspHelper.getNameNodeLabel(
+      cluster.getNameNode());
+    Assert.assertNotNull(nameNodeLabel);
+    Assert.assertFalse(nameNodeLabel.isEmpty());
+  }
+
+  /**
+   * Tests that passing a null FSNamesystem to generateSnapshotReport does not
+   * throw NullPointerException.
+   */
+  @Test
+  public void testGenerateSnapshotReportNullNamesystem() throws Exception {
+    NamenodeJspHelper.generateSnapshotReport(mock(JspWriter.class), null);
+  }
+
+  /**
+   * Tests that redirectToRandomDataNode does not throw NullPointerException if
+   * it finds a null FSNamesystem.
+   */
+  @Test(expected=IOException.class)
+  public void testRedirectToRandomDataNodeNullNamesystem() throws Exception {
+    NameNode nn = mock(NameNode.class);
+    when(nn.getNamesystem()).thenReturn(null);
+    ServletContext context = mock(ServletContext.class);
+    when(context.getAttribute("name.node")).thenReturn(nn);
+    NamenodeJspHelper.redirectToRandomDataNode(context,
+      mock(HttpServletRequest.class), mock(HttpServletResponse.class));
+  }
+
+  /**
+   * Tests that XMLBlockInfo does not throw NullPointerException if it finds a
+   * null FSNamesystem.
+   */
+  @Test
+  public void testXMLBlockInfoNullNamesystem() throws IOException {
+    XMLOutputter doc = new XMLOutputter(mock(JspWriter.class), "UTF-8");
+    new NamenodeJspHelper.XMLBlockInfo(null, 1L).toXML(doc);
+  }
+
+  /**
+   * Tests that XMLCorruptBlockInfo does not throw NullPointerException if it
+   * finds a null FSNamesystem.
+   */
+  @Test
+  public void testXMLCorruptBlockInfoNullNamesystem() throws IOException {
+    XMLOutputter doc = new XMLOutputter(mock(JspWriter.class), "UTF-8");
+    new NamenodeJspHelper.XMLCorruptBlockInfo(null, mock(Configuration.class),
+      10, 1L).toXML(doc);
+  }
+
   /**
    * Checks if the list contains any string that partially matches the regex.
    *