HDFS-4373. Merging change r1502328 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1502423 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -96,6 +96,8 @@ Release 2.1.0-beta - 2013-07-02
 
     HDFS-4372. Track NameNode startup progress. (cnauroth)
 
+    HDFS-4373. Add HTTP API for querying NameNode startup progress. (cnauroth)
+    
   IMPROVEMENTS
 
     HDFS-4461. DirectoryScanner: volume path prefix takes up memory for every

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

@@ -194,6 +194,8 @@ public class NameNodeHttpServer {
   }
 
   private static void setupServlets(HttpServer httpServer, Configuration conf) {
+    httpServer.addInternalServlet("startupProgress",
+        StartupProgressServlet.PATH_SPEC, StartupProgressServlet.class);
     httpServer.addInternalServlet("getDelegationToken",
         GetDelegationTokenServlet.PATH_SPEC, 
         GetDelegationTokenServlet.class, true);

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

@@ -0,0 +1,135 @@
+/**
+ * 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.namenode;
+
+import java.io.IOException;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.Phase;
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgress;
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgressView;
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.Step;
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.StepType;
+import org.apache.hadoop.io.IOUtils;
+import org.codehaus.jackson.JsonFactory;
+import org.codehaus.jackson.JsonGenerator;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+
+/**
+ * Servlet that provides a JSON representation of the namenode's current startup
+ * progress.
+ */
+@InterfaceAudience.Private
+@SuppressWarnings("serial")
+public class StartupProgressServlet extends DfsServlet {
+
+  private static final String COUNT = "count";
+  private static final String ELAPSED_TIME = "elapsedTime";
+  private static final String FILE = "file";
+  private static final String NAME = "name";
+  private static final String PERCENT_COMPLETE = "percentComplete";
+  private static final String PHASES = "phases";
+  private static final String SIZE = "size";
+  private static final String STATUS = "status";
+  private static final String STEPS = "steps";
+  private static final String TOTAL = "total";
+
+  public static final String PATH_SPEC = "/startupProgress";
+
+  @Override
+  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
+      throws IOException {
+    resp.setContentType("application/json; charset=UTF-8");
+    StartupProgress prog = NameNodeHttpServer.getStartupProgressFromContext(
+      getServletContext());
+    StartupProgressView view = prog.createView();
+    JsonGenerator json = new JsonFactory().createJsonGenerator(resp.getWriter());
+    try {
+      json.writeStartObject();
+      json.writeNumberField(ELAPSED_TIME, view.getElapsedTime());
+      json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete());
+      json.writeArrayFieldStart(PHASES);
+
+      for (Phase phase: view.getPhases()) {
+        json.writeStartObject();
+        json.writeStringField(NAME, phase.getName());
+        json.writeStringField(STATUS, view.getStatus(phase).toString());
+        json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase));
+        json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase));
+        writeStringFieldIfNotNull(json, FILE, view.getFile(phase));
+        writeNumberFieldIfDefined(json, SIZE, view.getSize(phase));
+        json.writeArrayFieldStart(STEPS);
+
+        for (Step step: view.getSteps(phase)) {
+          json.writeStartObject();
+          StepType type = step.getType();
+          String name = type != null ? type.getName() : null;
+          writeStringFieldIfNotNull(json, NAME, name);
+          json.writeNumberField(COUNT, view.getCount(phase, step));
+          writeStringFieldIfNotNull(json, FILE, step.getFile());
+          writeNumberFieldIfDefined(json, SIZE, step.getSize());
+          json.writeNumberField(TOTAL, view.getTotal(phase, step));
+          json.writeNumberField(PERCENT_COMPLETE, view.getPercentComplete(phase,
+            step));
+          json.writeNumberField(ELAPSED_TIME, view.getElapsedTime(phase, step));
+          json.writeEndObject();
+        }
+
+        json.writeEndArray();
+        json.writeEndObject();
+      }
+
+      json.writeEndArray();
+      json.writeEndObject();
+    } finally {
+      IOUtils.cleanup(LOG, json);
+    }
+  }
+
+  /**
+   * Writes a JSON number field only if the value is defined.
+   * 
+   * @param json JsonGenerator to receive output
+   * @param key String key to put
+   * @param value long value to put
+   * @throws IOException if there is an I/O error
+   */
+  private static void writeNumberFieldIfDefined(JsonGenerator json, String key,
+      long value) throws IOException {
+    if (value != Long.MIN_VALUE) {
+      json.writeNumberField(key, value);
+    }
+  }
+
+  /**
+   * Writes a JSON string field only if the value is non-null.
+   * 
+   * @param json JsonGenerator to receive output
+   * @param key String key to put
+   * @param value String value to put
+   * @throws IOException if there is an I/O error
+   */
+  private static void writeStringFieldIfNotNull(JsonGenerator json, String key,
+      String value) throws IOException {
+    if (value != null) {
+      json.writeStringField(key, value);
+    }
+  }
+}

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

@@ -0,0 +1,247 @@
+/**
+ * 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.namenode;
+
+import static org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgressTestHelper.*;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Map;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import com.google.common.collect.ImmutableMap;
+import org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgress;
+import org.junit.Before;
+import org.junit.Test;
+import org.mortbay.util.ajax.JSON;
+
+public class TestStartupProgressServlet {
+
+  private HttpServletRequest req;
+  private HttpServletResponse resp;
+  private ByteArrayOutputStream respOut;
+  private StartupProgress startupProgress;
+  private StartupProgressServlet servlet;
+
+  @Before
+  public void setUp() throws Exception {
+    startupProgress = new StartupProgress();
+    ServletContext context = mock(ServletContext.class);
+    when(context.getAttribute(NameNodeHttpServer.STARTUP_PROGRESS_ATTRIBUTE_KEY))
+      .thenReturn(startupProgress);
+    servlet = mock(StartupProgressServlet.class);
+    when(servlet.getServletContext()).thenReturn(context);
+    doCallRealMethod().when(servlet).doGet(any(HttpServletRequest.class),
+      any(HttpServletResponse.class));
+    req = mock(HttpServletRequest.class);
+    respOut = new ByteArrayOutputStream();
+    PrintWriter writer = new PrintWriter(respOut);
+    resp = mock(HttpServletResponse.class);
+    when(resp.getWriter()).thenReturn(writer);
+  }
+
+  @Test
+  public void testInitialState() throws Exception {
+    String respBody = doGetAndReturnResponseBody();
+    assertNotNull(respBody);
+
+    Map<String, Object> expected = ImmutableMap.<String, Object>builder()
+      .put("percentComplete", 0.0f)
+      .put("phases", Arrays.<Object>asList(
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingFsImage")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingEdits")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SavingCheckpoint")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SafeMode")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build()))
+      .build();
+
+    assertEquals(JSON.toString(expected), filterJson(respBody));
+  }
+
+  @Test
+  public void testRunningState() throws Exception {
+    setStartupProgressForRunningState(startupProgress);
+    String respBody = doGetAndReturnResponseBody();
+    assertNotNull(respBody);
+
+    Map<String, Object> expected = ImmutableMap.<String, Object>builder()
+      .put("percentComplete", 0.375f)
+      .put("phases", Arrays.<Object>asList(
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingFsImage")
+          .put("status", "COMPLETE")
+          .put("percentComplete", 1.0f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("name", "Inodes")
+              .put("count", 100L)
+              .put("total", 100L)
+              .put("percentComplete", 1.0f)
+              .build()
+          ))
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingEdits")
+          .put("status", "RUNNING")
+          .put("percentComplete", 0.5f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("count", 100L)
+              .put("file", "file")
+              .put("size", 1000L)
+              .put("total", 200L)
+            .put("percentComplete", 0.5f)
+              .build()
+          ))
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SavingCheckpoint")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SafeMode")
+          .put("status", "PENDING")
+          .put("percentComplete", 0.0f)
+          .put("steps", Collections.emptyList())
+          .build()))
+      .build();
+
+    assertEquals(JSON.toString(expected), filterJson(respBody));
+  }
+
+  @Test
+  public void testFinalState() throws Exception {
+    setStartupProgressForFinalState(startupProgress);
+    String respBody = doGetAndReturnResponseBody();
+    assertNotNull(respBody);
+
+    Map<String, Object> expected = ImmutableMap.<String, Object>builder()
+      .put("percentComplete", 1.0f)
+      .put("phases", Arrays.<Object>asList(
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingFsImage")
+          .put("status", "COMPLETE")
+          .put("percentComplete", 1.0f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("name", "Inodes")
+              .put("count", 100L)
+              .put("total", 100L)
+              .put("percentComplete", 1.0f)
+              .build()
+          ))
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "LoadingEdits")
+          .put("status", "COMPLETE")
+          .put("percentComplete", 1.0f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("count", 200L)
+              .put("file", "file")
+              .put("size", 1000L)
+              .put("total", 200L)
+              .put("percentComplete", 1.0f)
+              .build()
+          ))
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SavingCheckpoint")
+          .put("status", "COMPLETE")
+          .put("percentComplete", 1.0f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("name", "Inodes")
+              .put("count", 300L)
+              .put("total", 300L)
+              .put("percentComplete", 1.0f)
+              .build()
+          ))
+          .build(),
+        ImmutableMap.<String, Object>builder()
+          .put("name", "SafeMode")
+          .put("status", "COMPLETE")
+          .put("percentComplete", 1.0f)
+          .put("steps", Collections.<Object>singletonList(
+            ImmutableMap.<String, Object>builder()
+              .put("name", "AwaitingReportedBlocks")
+              .put("count", 400L)
+              .put("total", 400L)
+              .put("percentComplete", 1.0f)
+              .build()
+          ))
+          .build()))
+      .build();
+
+    assertEquals(JSON.toString(expected), filterJson(respBody));
+  }
+
+  /**
+   * Calls doGet on the servlet, captures the response body as a string, and
+   * returns it to the caller.
+   * 
+   * @return String response body
+   * @throws IOException thrown if there is an I/O error
+   */
+  private String doGetAndReturnResponseBody() throws IOException {
+    servlet.doGet(req, resp);
+    return new String(respOut.toByteArray(), "UTF-8");
+  }
+
+  /**
+   * Filters the given JSON response body, removing elements that would impede
+   * testing.  Specifically, it removes elapsedTime fields, because we cannot
+   * predict the exact values.
+   * 
+   * @param str String to filter
+   * @return String filtered value
+   */
+  private String filterJson(String str) {
+    return str.replaceAll("\"elapsedTime\":\\d+\\,", "")
+      .replaceAll("\\,\"elapsedTime\":\\d+", "");
+  }
+}