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1   /**
2    * Copyright 2011 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.monitoring;
21  
22  import java.io.IOException;
23  import java.io.PrintWriter;
24  import java.util.Map;
25  
26  import javax.servlet.http.HttpServlet;
27  import javax.servlet.http.HttpServletRequest;
28  
29  import org.apache.hadoop.hbase.executor.ExecutorService;
30  import org.apache.hadoop.hbase.executor.ExecutorService.ExecutorStatus;
31  import org.apache.hadoop.hbase.util.VersionInfo;
32  
33  public abstract class StateDumpServlet extends HttpServlet {
34    static final long DEFAULT_TAIL_KB = 100;
35    private static final long serialVersionUID = 1L;
36  
37    protected void dumpVersionInfo(PrintWriter out) {
38      VersionInfo.writeTo(out);
39    
40      out.println("Hadoop " + org.apache.hadoop.util.VersionInfo.getVersion());
41      out.println("Subversion " + org.apache.hadoop.util.VersionInfo.getUrl() + " -r " +
42          org.apache.hadoop.util.VersionInfo.getRevision());
43      out.println("Compiled by " + org.apache.hadoop.util.VersionInfo.getUser() +
44          " on " + org.apache.hadoop.util.VersionInfo.getDate());
45    }
46  
47    protected long getTailKbParam(HttpServletRequest request) {
48      String param = request.getParameter("tailkb");
49      if (param == null) {
50        return DEFAULT_TAIL_KB;
51      }
52      return Long.parseLong(param);
53    }
54  
55    protected void dumpExecutors(ExecutorService service, PrintWriter out)
56        throws IOException {
57      Map<String, ExecutorStatus> statuses = service.getAllExecutorStatuses();
58      for (ExecutorStatus status : statuses.values()) {
59        status.dumpTo(out, "  ");
60      }
61    }
62  }