| /** |
| * 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 DESC = "desc"; |
| 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(DESC, phase.getDescription()); |
| 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(); |
| if (type != null) { |
| json.writeStringField(NAME, type.getName()); |
| json.writeStringField(DESC, type.getDescription()); |
| } |
| 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); |
| } |
| } |
| } |