Using the BulkLoad Interface

Scenario

Users can use HBaseContext to use HBase in Spark applications, construct rowkey of the data to be inserted into RDDs, write RDDs into HFiles through the BulkLoad interface of HBaseContext. The following command is used to import the generated HFiles to the HBase table and will not be described in this section.

hbase org.apache.hadoop.hbase.mapreduce.LoadIncrementalHFiles {hfilePath} {tableName}

Data Planning

1. Run the hbase shell command on the client to go to the HBase command line.
2. Run the following command to create HBase tables:

   create 'bulkload-table-test','f1','f2'

Development Guideline

1. Construct the data to be imported into RDDs
2. Perform operations on HBase in HBaseContext mode and write RDDs into HFiles through the BulkLoad interface of HBaseContext.

Configuration Operations Before Running

In security mode, the Spark Core sample code needs to read two files (user.keytab and krb5.conf). The user.keytab and krb5.conf files are authentication files in the security mode. Download the authentication credentials of the user principal on FusionInsight Manager. The user in the example code is super, change the value to the prepared development user name.

Packaging the Project

• Use the Maven tool provided by IDEA to pack the project and generate a JAR file. For details, see Compiling and Running the Application.
• Upload the JAR package to any directory (for example, $SPARK_HOME) on the server where the Spark client is located.
• Upload the user.keytab and krb5.conf files to the server where the client is installed (The file upload path must be the same as the path of the generated JAR file).

To run the Spark on HBase example program, set spark.yarn.security.credentials.hbase.enabled (false by default) in the spark-defaults.conf file on the Spark client to true. Changing the spark.yarn.security.credentials.hbase.enabled value does not affect existing services. (To uninstall the HBase service, you need to change the value of this parameter back to false.) Set the value of the configuration item spark.inputFormat.cache.enabled to false.

Submitting Commands

Java Sample Code

The following code snippet is only for demonstration. For details about the code, see the JavaHBaseBulkLoadExample file in SparkOnHbaseJavaExample.

 public static void main(String[] args) throws IOException{
    if (args.length < 2) {
      System.out.println("JavaHBaseBulkLoadExample {outputPath} {tableName}");
      return;
    }
    LoginUtil.loginWithUserKeytab();
    String outputPath = args[0];
    String tableName = args[1];
    String columnFamily1 = "f1";
    String columnFamily2 = "f2";
    SparkConf sparkConf = new SparkConf().setAppName("JavaHBaseBulkLoadExample " + tableName);
    JavaSparkContext jsc = new JavaSparkContext(sparkConf);
    try {
      List<String> list= new ArrayList<String>();
      // row1
      list.add("1," + columnFamily1 + ",b,1");
      // row3
      list.add("3," + columnFamily1 + ",a,2");
      list.add("3," + columnFamily1 + ",b,1");
      list.add("3," + columnFamily2 + ",a,1");
      /* row2 */
      list.add("2," + columnFamily2 + ",a,3");
      list.add("2," + columnFamily2 + ",b,3");
      JavaRDD<String> rdd = jsc.parallelize(list);
      Configuration conf = HBaseConfiguration.create();
      JavaHBaseContext hbaseContext = new JavaHBaseContext(jsc, conf);
      hbaseContext.bulkLoad(rdd, TableName.valueOf(tableName),new BulkLoadFunction(), outputPath,
          new HashMap<byte[], FamilyHFileWriteOptions>(), false, HConstants.DEFAULT_MAX_FILE_SIZE);
    } finally {
      jsc.stop();
    }
  }

Scala Sample Code

The following code snippet is only for demonstration. For details about the code, see the HBaseBulkLoadExample file in SparkOnHbaseScalaExample.

  def main(args: Array[String]) {
      if(args.length < 2) {
        println("HBaseBulkLoadExample {outputPath} {tableName}
        return
      }
      LoginUtil.loginWithUserKeytab()
      val Array(outputPath, tableName) = args
      val columnFamily1 = "f1"
      val columnFamily2 = "f2"
      val sparkConf = new SparkConf().setAppName("JavaHBaseBulkLoadExample " + tableName)
      val sc = new SparkContext(sparkConf)
      try {
        val arr = Array("1," + columnFamily1 + ",b,1",
                        "2," + columnFamily1 + ",a,2",
                        "3," + columnFamily1 + ",b,1",
                        "3," + columnFamily2 + ",a,1",
                        "4," + columnFamily2 + ",a,3",
                        "5," + columnFamily2 + ",b,3")

          val rdd = sc.parallelize(arr)
          val config = HBaseConfiguration.create
          val hbaseContext = new HBaseContext(sc, config)
          hbaseContext.bulkLoad[String](rdd, 
            TableName.valueOf(tableName),
            (putRecord) => {
              if(putRecord.length > 0) {
                  val strArray = putRecord.split(",")
                  val kfq = new KeyFamilyQualifier(Bytes.toBytes(strArray(0)), Bytes.toBytes(strArray(1)), Bytes.toBytes(strArray(2)))
                  val ite = (kfq, Bytes.toBytes(strArray(3)))
                  val itea = List(ite).iterator
                  itea
                } else {
                  null
                }
              },
              outputPath)
          } finally {
              sc.stop()
          }
      }
  }
                

Python Sample Code

The following code snippet is only for demonstration. For details about the code, see the HBaseBulkLoadPythonExample file in SparkOnHbasePythonExample.

# -*- coding:utf-8 -*- 
""" 
[Note] 
(1) PySpark does not provide HBase-related APIs. In this example, Python is used to invoke Java code to implement required operations.
(2) If yarn-client is used, ensure that the spark.yarn.security.credentials.hbase.enabled parameter in the spark-defaults.conf file under Spark2x/spark/conf/ is set to true on the Spark2x client.
""" 
from py4j.java_gateway import java_import 
from pyspark.sql import SparkSession 
# Create a SparkSession instance. 
spark = SparkSession\ 
        .builder\ 
        .appName("JavaHBaseBulkLoadExample")\ 
        .getOrCreate() 
# Import required class to sc._jvm. 
java_import(spark._jvm, 'com.huawei.bigdata.spark.examples.HBaseBulkLoadPythonExample') 
# Create a class instance and invoke the method. Transfer the sc._jsc parameter. 
spark._jvm.HBaseBulkLoadPythonExample().hbaseBulkLoad(spark._jsc, sys.argv[1], sys.argv[2]) 
# Stop the SparkSession instance. 
spark.stop()