io.fabric8.hadoop.commands.NameNodeFormat.java Source code

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Here is the source code for io.fabric8.hadoop.commands.NameNodeFormat.java

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/**
 *  Copyright 2005-2014 Red Hat, Inc.
 *
 *  Red Hat 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 io.fabric8.hadoop.commands;

import java.io.File;
import java.util.Collection;
import java.util.Iterator;

import org.apache.felix.gogo.commands.Command;
import org.apache.felix.gogo.commands.Option;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
import org.apache.hadoop.hdfs.server.namenode.NameNode;

@Command(name = "namenode-format", scope = "hadoop", description = "Format a HDFS volume")
public class NameNodeFormat extends HadoopCommandSupport {

    @Option(name = "--force")
    boolean force;

    @Override
    protected void doExecute(Configuration conf) throws Exception {
        Collection<File> dirsToFormat = FSNamesystem.getNamespaceDirs(conf);
        for (Iterator<File> it = dirsToFormat.iterator(); it.hasNext();) {
            File curDir = it.next();
            if (!curDir.exists()) {
                continue;
            }
            if (!force) {
                System.err.print("Re-format filesystem in " + curDir + " ? (Y or N) ");
                System.err.flush();
                if (!(System.in.read() == 'Y')) {
                    System.err.println("Format aborted in " + curDir);
                    return;
                }
                while (System.in.read() != '\n')
                    ; // discard the enter-key
            }
        }
        NameNode.format(conf);
    }

}