org.cloudata.core.tablet.backup.BackupJob.java Source code

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Here is the source code for org.cloudata.core.tablet.backup.BackupJob.java

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/**
 * 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.cloudata.core.tablet.backup;

import java.io.IOException;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.cloudata.core.client.CTable;
import org.cloudata.core.common.conf.CloudataConf;
import org.cloudata.core.fs.CloudataFileSystem;
import org.cloudata.core.fs.GPath;
import org.cloudata.core.parallel.hadoop.DefaultTabletInputFormat;

/**
 * cloudata? ? ?? ? flat ?  MapReduce Job
 *
 */
public class BackupJob {
    /**
     *  mapreduce job 
     * @param tableName
     * @param outputPath
     * @throws IOException
     */
    public void runBackUp(String tableName, String outputPath) throws IOException {
        CloudataConf nconf = new CloudataConf();
        CloudataFileSystem fs = CloudataFileSystem.get(nconf);
        if (fs.exists(new GPath(outputPath))) {
            throw new IOException("Output path already exists:" + outputPath);
        }

        if (!CTable.existsTable(nconf, tableName)) {
            throw new IOException("No Table:" + tableName);
        }

        CTable ctable = CTable.openTable(nconf, tableName);
        String columns = "";
        for (String eachColumn : ctable.getTableSchema().getColumnsArray()) {
            columns += eachColumn + ",";
        }
        columns = columns.substring(0, columns.length() - 1);

        String jobName = tableName + " backup";
        JobConf jobConf = new JobConf(BackupJob.class);
        jobConf.setJobName(jobName);

        jobConf.setMapperClass(BackupMap.class);
        jobConf.setInputFormat(BackupTabletInputFormat.class);
        jobConf.set(DefaultTabletInputFormat.INPUT_TABLE, tableName);
        jobConf.set(DefaultTabletInputFormat.INPUT_COLUMN_LIST, columns);
        FileOutputFormat.setOutputPath(jobConf, new Path(outputPath));
        jobConf.set("mapred.textoutputformat.separator", ",");
        jobConf.setOutputFormat(TextOutputFormat.class);

        //map only
        jobConf.setNumReduceTasks(0);

        JobClient.runJob(jobConf);
    }

    public static void main(String[] args) throws IOException {

    }
}