Spark读取Hbase中的数据

needyit 2020-06-04

大家可能都知道很熟悉Spark的两种常见的数据读取方式(存放到RDD中):(1)、调用parallelize函数直接从集合中获取数据,并存入RDD中;Java版本如下:

JavaRDD<Integer> myRDD = sc.parallelize(Arrays.asList(1,2,3));

Scala版本如下:

val myRDD= sc.parallelize(List(1,2,3))

这种方式很简单,很容易就可以将一个集合中的数据变成RDD的初始化值;更常见的是(2)、从文本中读取数据到RDD中,这个文本可以是纯文本文件、可以是sequence文件;可以存放在本地(file://)、可以存放在HDFS(hdfs://)上,还可以存放在S3上。其实对文件来说,Spark支持Hadoop所支持的所有文件类型和文件存放位置。Java版如下:

/////////////////////////////////////////////////////////////////////
 User: 过往记忆
 Date: 14-6-29
 Time: 23:59
 bolg:
 本文地址:/archives/1051
 过往记忆博客,专注于hadoop、hive、spark、shark、flume的技术博客,大量的干货
 过往记忆博客微信公共帐号:iteblog_hadoop
/////////////////////////////////////////////////////////////////////
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
 
SparkConf conf = new SparkConf().setAppName("Simple Application");
JavaSparkContext sc = new JavaSparkContext(conf);
sc.addFile("wyp.data");
JavaRDD<String> lines = sc.textFile(SparkFiles.get("wyp.data"));

Scala版本如下:

import org.apache.spark.SparkContext
import org.apache.spark.SparkConf
 
val conf = new SparkConf().setAppName("Simple Application")
val sc = new SparkContext(conf)
sc.addFile("spam.data")
val inFile = sc.textFile(SparkFiles.get("spam.data"))

在实际情况下,我们需要的数据可能不是简单的存放在HDFS文本中,我们需要的数据可能就存放在Hbase中,那么我们如何用Spark来读取Hbase中的数据呢?本文的所有测试是基于Hadoop 2.2.0、Hbase 0.98.2、Spark 0.9.1,不同版本可能代码的编写有点不同。本文只是简单地用Spark来读取Hbase中的数据,如果需要对Hbase进行更强的操作,本文可能不能帮你。话不多说,Spark操作Hbase的Java版本代码如下:

package com.iteblog.spark;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
import org.apache.hadoop.hbase.util.Base64;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import scala.Serializable;
import scala.Tuple2;

import java.io.IOException;
import java.util.List;

/**
 * User: iteblog
 * Date: 14-6-27
 * Time: 下午5:18
 *blog: http://www.iteblog.com
 *
 * Usage: bin/spark-submit --master yarn-cluster --class com.iteblog.spark.SparkFromHbase
 * --jars /home/q/hbase/hbase-0.96.0-hadoop2/lib/htrace-core-2.01.jar,
 * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-common-0.96.0-hadoop2.jar,
 * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-client-0.96.0-hadoop2.jar,
 * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-protocol-0.96.0-hadoop2.jar,
 * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-server-0.96.0-hadoop2.jar
 * ./spark_2.10-1.0.jar
 */
public class SparkFromHbase implements Serializable {

    /**
     * copy from org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil
     *
     * @param scan
     * @return
     * @throws IOException
     */
    String convertScanToString(Scan scan) throws IOException {
        ClientProtos.Scan proto = ProtobufUtil.toScan(scan);
        return Base64.encodeBytes(proto.toByteArray());
    }

    public void start() {
        SparkConf sparkConf = new SparkConf();
        JavaSparkContext sc = new JavaSparkContext(sparkConf);


        Configuration conf = HBaseConfiguration.create();

        Scan scan = new Scan();
        //scan.setStartRow(Bytes.toBytes("195861-1035177490"));
        //scan.setStopRow(Bytes.toBytes("195861-1072173147"));
        scan.addFamily(Bytes.toBytes("cf"));
        scan.addColumn(Bytes.toBytes("cf"), Bytes.toBytes("col_1"));

        try {

            String tableName = "wyp";
            conf.set(TableInputFormat.INPUT_TABLE, tableName);
            conf.set(TableInputFormat.SCAN, convertScanToString(scan));


            JavaPairRDD<ImmutableBytesWritable, Result> hBaseRDD = sc.newAPIHadoopRDD(conf,
                    TableInputFormat.class, ImmutableBytesWritable.class,
                    Result.class);

            JavaPairRDD<String, Integer> levels = hBaseRDD.mapToPair(
                    new PairFunction<Tuple2<ImmutableBytesWritable, Result>, String, Integer>() {
                        @Override
                        public Tuple2<String, Integer> call(Tuple2<ImmutableBytesWritable, Result> immutableBytesWritableResultTuple2) throws Exception {
                            byte[] o = immutableBytesWritableResultTuple2._2().getValue(Bytes.toBytes("cf"), Bytes.toBytes("col_1"));
                            if (o != null) {
                                return new Tuple2<String, Integer>(new String(o), 1);
                            }
                            return null;
                        }
                    });

            JavaPairRDD<String, Integer> counts = levels.reduceByKey(
                    new Function2<Integer, Integer, Integer>() {
                        @Override
                        public Integer call(Integer i1, Integer i2) {
                            return i1 + i2;
                        }
                    });

            List<Tuple2<String, Integer>> output = counts.collect();
            for (Tuple2 tuple : output) {
                System.out.println(tuple._1() + ": " + tuple._2());
            }

            sc.stop();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        new SparkFromHbase().start();
        System.exit(0);
    }
}

这样本段代码段是从Hbase表名为flight_wap_order_log的数据库中读取cf列簇上的airName一列的数据,这样我们就可以对myRDD进行相应的操作:

System.out.println(myRDD.count());

本段代码需要在pom.xml文件加入以下依赖:

<dependency>
        <groupId>org.apache.spark</groupId>
        <artifactId>spark-core_2.10</artifactId>
        <version>0.9.1</version>
</dependency>
 
<dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase</artifactId>
        <version>0.98.2-hadoop2</version>
</dependency>
 
<dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-client</artifactId>
        <version>0.98.2-hadoop2</version>
</dependency>
 
<dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-common</artifactId>
        <version>0.98.2-hadoop2</version>
</dependency>
 
<dependency>
        <groupId>org.apache.hbase</groupId>
        <artifactId>hbase-server</artifactId>
        <version>0.98.2-hadoop2</version>
</dependency>

Scala版如下:

import org.apache.spark._
import org.apache.spark.rdd.NewHadoopRDD
import org.apache.hadoop.hbase.{HBaseConfiguration, HTableDescriptor}
import org.apache.hadoop.hbase.client.HBaseAdmin
import org.apache.hadoop.hbase.mapreduce.TableInputFormat
 
/////////////////////////////////////////////////////////////////////
 User: 过往记忆
 Date: 14-6-29
 Time: 23:59
 bolg:
 本文地址:/archives/1051
 过往记忆博客,专注于hadoop、hive、spark、shark、flume的技术博客,大量的干货
 过往记忆博客微信公共帐号:iteblog_hadoop
/////////////////////////////////////////////////////////////////////
 
object HBaseTest {
  def main(args: Array[String]) {
    val sc = new SparkContext(args(0), "HBaseTest",
      System.getenv("SPARK_HOME"), SparkContext.jarOfClass(this.getClass))
 
    val conf = HBaseConfiguration.create()
    conf.set(TableInputFormat.INPUT_TABLE, args(1))
 
    val hBaseRDD = sc.newAPIHadoopRDD(conf, classOf[TableInputFormat],
      classOf[org.apache.hadoop.hbase.io.ImmutableBytesWritable],
      classOf[org.apache.hadoop.hbase.client.Result])
 
    hBaseRDD.count()
 
    System.exit(0)
  }
}

我们需要在加入如下依赖:

libraryDependencies ++= Seq(
        "org.apache.spark" % "spark-core_2.10" % "0.9.1",
        "org.apache.hbase" % "hbase" % "0.98.2-hadoop2",
        "org.apache.hbase" % "hbase-client" % "0.98.2-hadoop2",
        "org.apache.hbase" % "hbase-common" % "0.98.2-hadoop2",
        "org.apache.hbase" % "hbase-server" % "0.98.2-hadoop2"
)

在测试的时候,需要配置好Hbase、Hadoop环境,否则程序会出现问题,特别是让程序找到Hbase-site.xml配置文件。

package com.iteblog.spark;
  
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
 import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
 import org.apache.hadoop.hbase.util.Base64;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.spark.SparkConf;
 import org.apache.spark.api.java.JavaPairRDD;
 import org.apache.spark.api.java.JavaSparkContext;
 import org.apache.spark.api.java.function.Function2;
 import org.apache.spark.api.java.function.PairFunction;
 import scala.Serializable;
 import scala.Tuple2;
  
 import java.io.IOException;
 import java.util.List;
  
 /**
  * User: iteblog
  * Date: 14-6-27
  * Time: 下午5:18
  *blog: http://www.iteblog.com
  *
  * Usage: bin/spark-submit --master yarn-cluster --class com.iteblog.spark.SparkFromHbase
  * --jars /home/q/hbase/hbase-0.96.0-hadoop2/lib/htrace-core-2.01.jar,
  * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-common-0.96.0-hadoop2.jar,
  * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-client-0.96.0-hadoop2.jar,
  * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-protocol-0.96.0-hadoop2.jar,
  * /home/q/hbase/hbase-0.96.0-hadoop2/lib/hbase-server-0.96.0-hadoop2.jar
  * ./spark_2.10-1.0.jar
  */
 public class SparkFromHbase implements Serializable {
  
  /**
  * copy from org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil
  *
  * @param scan
  * @return
  * @throws IOException
  */
  String convertScanToString(Scan scan) throws IOException {
  ClientProtos.Scan proto = ProtobufUtil.toScan(scan);
  return Base64.encodeBytes(proto.toByteArray());
  }
  
  public void start() {
  SparkConf sparkConf = new SparkConf();
  JavaSparkContext sc = new JavaSparkContext(sparkConf);
  
  
  Configuration conf = HBaseConfiguration.create();
  
  Scan scan = new Scan();
  //scan.setStartRow(Bytes.toBytes("195861-1035177490"));
  //scan.setStopRow(Bytes.toBytes("195861-1072173147"));
  scan.addFamily(Bytes.toBytes("cf"));
  scan.addColumn(Bytes.toBytes("cf"), Bytes.toBytes("col_1"));
  
  try {
  
  String tableName = "wyp";
  conf.set(TableInputFormat.INPUT_TABLE, tableName);
  conf.set(TableInputFormat.SCAN, convertScanToString(scan));
  
  
  JavaPairRDD<ImmutableBytesWritable, Result> hBaseRDD = sc.newAPIHadoopRDD(conf,
  TableInputFormat.class, ImmutableBytesWritable.class,
  Result.class);
  
  JavaPairRDD<String, Integer> levels = hBaseRDD.mapToPair(
  new PairFunction<Tuple2<ImmutableBytesWritable, Result>, String, Integer>() {
  @Override
  public Tuple2<String, Integer> call(Tuple2<ImmutableBytesWritable, Result> immutableBytesWritableResultTuple2) throws Exception {
  byte[] o = immutableBytesWritableResultTuple2._2().getValue(Bytes.toBytes("cf"), Bytes.toBytes("col_1"));
  if (o != null) {
  return new Tuple2<String, Integer>(new String(o), 1);
  }
  return null;
  }
  });
  
  JavaPairRDD<String, Integer> counts = levels.reduceByKey(
  new Function2<Integer, Integer, Integer>() {
  @Override
  public Integer call(Integer i1, Integer i2) {
  return i1 + i2;
  }
  });
  
  List<Tuple2<String, Integer>> output = counts.collect();
  for (Tuple2 tuple : output) {
  System.out.println(tuple._1() + ": " + tuple._2());
  }
  
  sc.stop();
  
  } catch (Exception e) {
  e.printStackTrace();
  }
  }
  
  public static void main(String[] args) throws InterruptedException {
  new SparkFromHbase().start();
  System.exit(0);
  }
 }

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