Writing Data to HBase Tables In Batches Using SparkStreaming

Scenario

Users can use HBaseContext to perform operations on HBase in Spark applications and write streaming data to HBase tables using the streamBulkPut interface.

Data Planning

1. Create a session connected to the client and run the hbase shell command in the session to go to the HBase command line.
2. Run the following command in the HBase command line to create an HBase table:

   create 'streamingTable','cf1'

3. In another session of the client, run the Linux command to construct a port for receiving data. The command may be different for servers running different operating systems. For the SUSE operating system, the following command is used: netcat -lk 9999.

   nc -lk 9999

   

   To construct a port for receiving data, you need to install netcat on the server where the client is located.

Development Guideline

1. Use SparkStreaming to continuously read data from a specific port.
2. Write the read Dstream to HBase tables through the streamBulkPut interface.

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.

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 JavaHBaseStreamingBulkPutExample file in SparkOnHbaseJavaExample.

The awaitTerminationOrTimeout() method is used to set the task timeout interval (in milliseconds). You are advised to set this parameter based on the expected task execution time.

  public static void main(String[] args) throws IOException {
    if (args.length < 4) {
      System.out.println("JavaHBaseBulkPutExample  " +
              "{host} {port} {tableName}");
      return;
    }
    String host = args[0];
    String port = args[1];
    String tableName = args[2];
    String columnFamily = args[3];
    SparkConf sparkConf =
            new SparkConf().setAppName("JavaHBaseStreamingBulkPutExample " +
                    tableName + ":" + port + ":" + tableName);
    JavaSparkContext jsc = new JavaSparkContext(sparkConf);
    try {
      JavaStreamingContext jssc =
              new JavaStreamingContext(jsc, new Duration(1000));
      JavaReceiverInputDStream<String> javaDstream =
              jssc.socketTextStream(host, Integer.parseInt(port));
      Configuration conf = HBaseConfiguration.create();
      JavaHBaseContext hbaseContext = new JavaHBaseContext(jsc, conf);
      hbaseContext.streamBulkPut(javaDstream,
              TableName.valueOf(tableName),
              new PutFunction(columnFamily));
      jssc.start();
      jssc.awaitTerminationOrTimeout(60000);
      jssc.stop(false,true);
    }catch(InterruptedException e){
      e.printStackTrace();
    } finally {
      jsc.stop();
    }
  }

Scala Sample Code

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

The awaitTerminationOrTimeout() method is used to set the task timeout interval (in milliseconds). You are advised to set this parameter based on the expected task execution time.

  def main(args: Array[String]): Unit = {
    val host = args(0)
    val port = args(1)
    val tableName = args(2)
    val columnFamily = args(3)
    val conf = new SparkConf()
    conf.setAppName("HBase Streaming Bulk Put Example")
    val sc = new SparkContext(conf)
    try {
      val config = HBaseConfiguration.create()
      val hbaseContext = new HBaseContext(sc, config)
      val ssc = new StreamingContext(sc, Seconds(1))
      val lines = ssc.socketTextStream(host, port.toInt)
      hbaseContext.streamBulkPut[String](lines,
        TableName.valueOf(tableName),
        (putRecord) => {
          if (putRecord.length() > 0) {
            val put = new Put(Bytes.toBytes(putRecord))
            put.addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes("foo"), Bytes.toBytes("bar"))
            put
          } else {
            null
          }
        })
      ssc.start()
      ssc.awaitTerminationOrTimeout(60000)
      ssc.stop(stopSparkContext = false)
    } finally {
      sc.stop()
    }
  }

Python Sample Code

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

# -*- coding:utf-8 -*-
"""
[Note]
PySpark does not provide HBase-related APIs. In this eample, Python is used to invoke Java code to implement required operations.
"""
from py4j.java_gateway import java_import
from pyspark.sql import SparkSession
# Create a SparkSession instance.
spark = SparkSession\
.builder\
.appName("JavaHBaseStreamingBulkPutExample")\
.getOrCreate()
# Import required class to sc._jvm.
java_import(spark._jvm, 'com.huawei.bigdata.spark.examples.streaming.JavaHBaseStreamingBulkPutExample')
# Create class instance and invoke the method. Transfer the sc._jsc parameter.
spark._jvm.JavaHBaseStreamingBulkPutExample().execute(spark._jsc, sys.argv)
# Stop SparkSession.
spark.stop()