hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterStatusServlet.java

   1 /**
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.master;
  20
  21 import java.io.IOException;
  22 import java.util.List;
  23 import java.util.Map;
  24 import java.util.Set;
  25 import javax.servlet.http.HttpServlet;
  26 import javax.servlet.http.HttpServletRequest;
  27 import javax.servlet.http.HttpServletResponse;
  28 import org.apache.hadoop.conf.Configuration;
  29 import org.apache.hadoop.hbase.ServerName;
  30 import org.apache.hadoop.hbase.tmpl.master.MasterStatusTmpl;
  31 import org.apache.hadoop.hbase.util.FSUtils;
  32 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
  33 import org.apache.yetus.audience.InterfaceAudience;
  34
  35 /**
  36  * The servlet responsible for rendering the index page of the
  37  * master.
  38  */
  39 @InterfaceAudience.Private
  40 public class MasterStatusServlet extends HttpServlet {
  41   private static final long serialVersionUID = 1L;
  42
  43   @Override
  44   public void doGet(HttpServletRequest request, HttpServletResponse response)
  45     throws IOException
  46   {
  47     HMaster master = (HMaster) getServletContext().getAttribute(HMaster.MASTER);
  48     assert master != null : "No Master in context!";
  49
  50     response.setContentType("text/html");
  51
  52     Configuration conf = master.getConfiguration();
  53
  54     Map<String, Integer> frags = getFragmentationInfo(master, conf);
  55     ServerName metaLocation = null;
  56     List<ServerName> servers = null;
  57     Set<ServerName> deadServers = null;
  58
  59     if(master.isActiveMaster()) {
  60       metaLocation = getMetaLocationOrNull(master);
  61       ServerManager serverManager = master.getServerManager();
  62       if (serverManager != null) {
  63         deadServers = serverManager.getDeadServers().copyServerNames();
  64         servers = serverManager.getOnlineServersList();
  65       }
  66     }
  67
  68     MasterStatusTmpl tmpl = new MasterStatusTmpl()
  69       .setFrags(frags)
  70       .setMetaLocation(metaLocation)
  71       .setServers(servers)
  72       .setDeadServers(deadServers)
  73       .setCatalogJanitorEnabled(master.isCatalogJanitorEnabled());
  74
  75     if (request.getParameter("filter") != null)
  76       tmpl.setFilter(request.getParameter("filter"));
  77     if (request.getParameter("format") != null)
  78       tmpl.setFormat(request.getParameter("format"));
  79     tmpl.render(response.getWriter(), master);
  80   }
  81
  82   private ServerName getMetaLocationOrNull(HMaster master) {
  83     return MetaTableLocator.getMetaRegionLocation(master.getZooKeeper());
  84   }
  85
  86   private Map<String, Integer> getFragmentationInfo(
  87       HMaster master, Configuration conf) throws IOException {
  88     boolean showFragmentation = conf.getBoolean(
  89         "hbase.master.ui.fragmentation.enabled", false);
  90     if (showFragmentation) {
  91       return FSUtils.getTableFragmentation(master);
  92     } else {
  93       return null;
  94     }
  95   }
  96 }