HADOOP-688. Adding file missing from prior commit.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk@475364 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/dfs/DFSAdmin.java

@@ -0,0 +1,223 @@
+/**
+ * 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.dfs;
+
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.ipc.RemoteException;
+import org.apache.hadoop.ipc.RPC;
+
+/**
+ * This class provides some DFS administrative access.
+ *
+ * @author Dhruba Borthakur
+ */
+public class DFSAdmin extends DFSShell {
+
+    /**
+     * Construct a DFSAdmin object.
+     */
+    public DFSAdmin() {
+        super();
+    }
+
+    /**
+     * Gives a report on how the FileSystem is doing.
+     * @exception IOException if the filesystem does not exist.
+     */
+    public void report() throws IOException {
+      if (fs instanceof DistributedFileSystem) {
+        DistributedFileSystem dfs = (DistributedFileSystem) fs;
+        long raw = dfs.getRawCapacity();
+        long rawUsed = dfs.getRawUsed();
+        long used = dfs.getUsed();
+        boolean mode = dfs.setSafeMode(
+                           FSConstants.SafeModeAction.SAFEMODE_GET);
+
+        if (mode) {
+          System.out.println("Safe mode is ON");
+        }
+        System.out.println("Total raw bytes: " + raw
+                           + " (" + byteDesc(raw) + ")");
+        System.out.println("Used raw bytes: " + rawUsed
+                           + " (" + byteDesc(rawUsed) + ")");
+        System.out.println("% used: "
+                           + limitDecimal(((1.0 * rawUsed) / raw) * 100, 2)
+                           + "%");
+        System.out.println();
+        System.out.println("Total effective bytes: " + used
+                           + " (" + byteDesc(used) + ")");
+        System.out.println("Effective replication multiplier: "
+                           + (1.0 * rawUsed / used));
+
+        System.out.println("-------------------------------------------------");
+        DatanodeInfo[] info = dfs.getDataNodeStats();
+        System.out.println("Datanodes available: " + info.length);
+        System.out.println();
+        for (int i = 0; i < info.length; i++) {
+          System.out.println(info[i].getDatanodeReport());
+          System.out.println();
+        }
+      }
+    }
+
+    /**
+     * Safe mode maintenance command.
+     * Usage: java DFSAdmin -safemode [enter | leave | get]
+     * @param argv List of of command line parameters.
+     * @param idx The index of the command that is being processed.
+     * @exception IOException if the filesystem does not exist.
+     */
+    public void setSafeMode(String[] argv, int idx) throws IOException {
+      final String safeModeUsage = "Usage: java DFSAdmin -safemode "
+                                   + "[enter | leave | get]";
+      if (!(fs instanceof DistributedFileSystem)) {
+        System.out.println("FileSystem is " + fs.getName());
+        return;
+      }
+      if (idx != argv.length - 1) {
+        printUsage("-safemode");
+        return;
+      }
+      FSConstants.SafeModeAction action;
+
+      if ("leave".equalsIgnoreCase(argv[idx])) {
+        action = FSConstants.SafeModeAction.SAFEMODE_LEAVE;
+      } else if ("enter".equalsIgnoreCase(argv[idx])) {
+        action = FSConstants.SafeModeAction.SAFEMODE_ENTER;
+      } else if ("get".equalsIgnoreCase(argv[idx])) {
+        action = FSConstants.SafeModeAction.SAFEMODE_GET;
+      } else {
+        printUsage("-safemode");
+        return;
+      }
+      DistributedFileSystem dfs = (DistributedFileSystem) fs;
+      boolean mode = dfs.setSafeMode(action);
+      System.out.println("Safe mode is " + (mode ? "ON" : "OFF"));
+    }
+
+    /**
+     * Displays format of commands.
+     * @param cmd The command that is being executed.
+     */
+    public void printUsage(String cmd) {
+          if ("-report".equals(cmd)) {
+            System.err.println("Usage: java DFSAdmin"
+                + " [report]");
+          } else if ("-safemode".equals(cmd)) {
+            System.err.println("Usage: java DFSAdmin"
+                + " [-safemode enter | leave | get]");
+          } else {
+            System.err.println("Usage: java DFSAdmin");
+            System.err.println("           [-report]");
+            System.err.println("           [-safemode enter | leave | get]");
+          }
+    }
+
+    /**
+     * @param argv The parameters passed to this program.
+     * @exception Exception if the filesystem does not exist.
+     * @return 0 on success, non zero on error.
+     */
+    public int run(String[] argv) throws Exception {
+
+        if (argv.length < 1) {
+            printUsage("");
+            return -1;
+        }
+
+        int exitCode = -1;
+        int i = 0;
+        String cmd = argv[i++];
+
+        //
+        // verify that we have enough command line parameters
+        //
+        if ("-safemode".equals(cmd)) {
+                if (argv.length != 2) {
+                  printUsage(cmd);
+                  return exitCode;
+                }
+        } else if ("-report".equals(cmd)) {
+                if (argv.length != 1) {
+                  printUsage(cmd);
+                  return exitCode;
+                }
+        }
+
+        // initialize DFSAdmin
+        try {
+            init();
+        } catch (RPC.VersionMismatch v) {
+            System.err.println("Version Mismatch between client and server"
+                               + "... command aborted.");
+            return exitCode;
+        } catch (IOException e) {
+            System.err.println("Bad connection to DFS... command aborted.");
+            return exitCode;
+        }
+
+        exitCode = 0;
+        try {
+            if ("-report".equals(cmd)) {
+                report();
+            } else if ("-safemode".equals(cmd)) {
+                setSafeMode(argv, i);
+            } else {
+                exitCode = -1;
+                System.err.println(cmd.substring(1) + ": Unknown command");
+                printUsage("");
+            }
+        } catch (RemoteException e) {
+          //
+          // This is a error returned by hadoop server. Print
+          // out the first line of the error mesage, ignore the stack trace.
+          exitCode = -1;
+          try {
+            String[] content;
+            content = e.getLocalizedMessage().split("\n");
+            System.err.println(cmd.substring(1) + ": "
+                               + content[0]);
+          } catch (Exception ex) {
+            System.err.println(cmd.substring(1) + ": "
+                               + ex.getLocalizedMessage());
+          }
+        } catch (IOException e) {
+          //
+          // IO exception encountered locally.
+          //
+          exitCode = -1;
+          System.err.println(cmd.substring(1) + ": "
+                             + e.getLocalizedMessage());
+        } finally {
+            fs.close();
+        }
+        return exitCode;
+    }
+
+    /**
+     * main() has some simple utility methods.
+     * @param argv Command line parameters.
+     * @exception Exception if the filesystem does not exist.
+     */
+    public static void main(String[] argv) throws Exception {
+        int res = new DFSAdmin().doMain(new Configuration(), argv);
+        System.exit(res);
+    }
+}