本帖最后由 pig2 于 2014-8-2 12:05 编辑
问题导读
1.你认为hbase入库有几种方式?
2.能否想到其中一种的实现方式?
3.根据想的内容,对比下面,说出自己的想法?
1. 预先生成HFile入库
这个地址有详细的说明http://www.aboutyun.com/thread-8603-1-1.html
2. 通过MapReduce入库
/* MapReduce 读取hdfs上的文件,以HTable.put(put)的方式在map中完成数据写入,无reduce过程*/
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class HBaseImport extends Configured implements Tool{
static final Log LOG = LogFactory.getLog(HBaseImport.class);
public static final String JOBNAME = "MRImport ";
public static class Map extends Mapper<LongWritable , Text, NullWritable, NullWritable>{
Configuration configuration = null;
HTable xTable = null;
private boolean wal = true;
static long count = 0;
@Override
protected void cleanup(Context context) throws IOException,
InterruptedException {
// TODO Auto-generated method stub
super.cleanup(context);
xTable.flushCommits();
xTable.close();
}
@Override
protected void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String all[] = value.toString().split("/t");
If(all.length==2){
put = new Put(Bytes.toBytes(all[0]))); put.add(Bytes.toBytes("xxx"),Bytes.toBytes("20110313"),Bytes.toBytes(all[1]));
}
if (!wal) {
put.setWriteToWAL(false);
}
xTable.put(put);
if ((++count % 100)==0) {
context.setStatus(count +" DOCUMENTS done!");
context.progress();
System.out.println(count +" DOCUMENTS done!");
}
}
@Override
protected void setup(Context context) throws IOException,
InterruptedException {
// TODO Auto-generated method stub
super.setup(context);
configuration = context.getConfiguration();
xTable = new HTable(configuration,"testKang");
xTable.setAutoFlush(false);
xTable.setWriteBufferSize(12*1024*1024);
wal = true;
}
}
@Override
public int run(String[] args) throws Exception {
String input = args[0];
Configuration conf = HBaseConfiguration.create(getConf());
conf.set("hbase.master", "m0:60000");
Job job = new Job(conf,JOBNAME);
job.setJarByClass(HBaseImport.class);
job.setMapperClass(Map.class);
job.setNumReduceTasks(0);
job.setInputFormatClass(TextInputFormat.class);
TextInputFormat.setInputPaths(job, input);
job.setOutputFormatClass(NullOutputFormat.class);
return job.waitForCompletion(true)?0:1;
}
public static void main(String[] args) throws IOException {
Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
int res = 1;
try {
res = ToolRunner.run(conf, new HBaseImport (), otherArgs);
} catch (Exception e) {
e.printStackTrace();
}
System.exit(res);
}
}
3. 通过Java程序入库
/* Java多线程读取本地磁盘上的文件,以HTable.put(put)的方式完成数据写入*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
public class InsertContactJava {
public static long startTime;
public static long rowkey = 0; //起始rowkey
public static final int lineCount = 100000; //每次提交时录入的行数
public static String tableName = "usercontact_kang"; //录入目的表名
public static int countLie = 8; //表的列数
public static void main(String[] args) throws IOException {
startTime = System.currentTimeMillis() / 1000;
System.out.println("start time = " + startTime);
Thread t1 = new Thread() {
@Override
public void run() {
try {
insert_one("/run/jar/123");
//loadByLieWithVector("/run/jar/123");
//loadByLieWithArrayList("/run/jar/123");
} catch (IOException e) {
e.printStackTrace();
}
}
};
t1.start();
}
public static void insert_one(String path) throws IOException {
Configuration conf = HBaseConfiguration.create();
HTable table = new HTable(conf, tableName);
File f = new File(path);
ArrayList<Put> list = new ArrayList<Put>();
BufferedReader br = new BufferedReader(new FileReader(f));
String tmp = br.readLine();
int count = 0;
while (tmp != null) {
if (list.size() > 10000) {
table.put(list);
table.flushCommits();
list.clear();
} else {
String arr_value[] = tmp.toString().split("/t", 10);
String first[] = arr_value[0].split("~", 5);
String second[] = arr_value[1].split("~", 5);
String rowname = getIncreasRowKey();
String firstaccount = first[0];
String firstprotocolid = first[1];
String firstdomain = first[2];
String inserttime = Utils.getToday("yyyyMMdd");
String secondaccount = second[0];
String secondprotocolid = second[1];
String seconddomain = second[2];
String timescount = Integer.valueOf(arr_value[2]).toString();
Put p = new Put(rowname.getBytes());
p.add(("ucvalue").getBytes(), "FIRSTACCOUNT".getBytes(),
firstaccount.getBytes());
p.add(("ucvalue").getBytes(), "FIRSTDOMAIN".getBytes(),
firstdomain.getBytes());
p.add(("ucvalue").getBytes(), "FIRSTPROTOCOLID".getBytes(),
firstprotocolid.getBytes());
p.add(("ucvalue").getBytes(), "INSERTTIME".getBytes(),
inserttime.getBytes());
p.add(("ucvalue").getBytes(), "SECONDACCOUNT".getBytes(),
secondaccount.getBytes());
p.add(("ucvalue").getBytes(), "SECONDDOMAIN".getBytes(),
seconddomain.getBytes());
p.add(("ucvalue").getBytes(), "SECONDPROTOCOLID".getBytes(),
secondprotocolid.getBytes());
p.add(("ucvalue").getBytes(), "TIMESCOUNT".getBytes(),
timescount.getBytes());
list.add(p);
}
tmp = br.readLine();
count++;
}
if (list.size() > 0) {
table.put(list);
table.flushCommits();
}
table.close();
System.out.println("total = " + count);
long endTime = System.currentTimeMillis() / 1000;
long costTime = endTime - startTime;
System.out.println("end time = " + endTime);
System.out.println(path + ": cost time = " + costTime);
}
4. 入库方式比较
Ø 生成HFile方式:
生成HFile的过程比较慢,生成HFile后写入hbase非常快,基本上就是hdfs上的mv过程.对于生成HFile方式入库的时候有一个改进的方案,就是先对数据排序,然后生成HFile。
HFile方式在所有的加载方案里面是最快的,不过有个前提——数据是第一次导入,表是空的。如果表中已经有了数据。HFile再导入到hbase的表中会触发split操作,最慢的时候这种操作会耗时1小时。
Ø MapReduce方式:
开始会很快,但是由于mr和hbase竞争资源,到一个特定的时间点会变很慢
Ø Java程序方式:
多客户端,多线程同时入库,目前看来是最好的方式,client和regionserver分开,硬盘读写分开,瓶颈只在网络和内存上。咨询了一些牛人,大多推荐这种方式,并且一定要多客户端,多线程。关于入库效率的调优,在我另一篇博客中有说明。
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