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
- Create a session connected to the client and run the hbase shell command in the session to go to the HBase command line.
- Run the following command in the HBase command line to create an HBase table:
- 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
After the command for submitting a task is executed, enter the data to be submitted in this command and receive the data through the HBase table.
To construct a port for receiving data, you need to install netcat on the server where the client is located.
Development Guideline
- Use SparkStreaming to continuously read data from a specific port.
- Write the read Dstream to HBase tables through the streamBulkPut interface.
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 the FusionInsight Manager page. The user in the sample 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
Assume that the JAR package name is spark-hbaseContext-test-1.0.jar that is stored in the $SPARK_HOME directory on the client. The following commands are executed in the $SPARK_HOME directory, and Java is displayed before the class name of the Java interface. For details, see the sample code.
- yarn-client mode:
Java/Scala version. (The class name must be the same as the actual code. The following is only an example.) ${ip} must be the IP address of the host where the nc -lk 9999 command is executed.
bin/spark-submit --master yarn --deploy-mode client --class com.huawei.bigdata.spark.examples.streaming.JavaHBaseStreamingBulkPutExample SparkOnHbaseJavaExample.jar ${ip} 9999 streamingTable cf1
Python version. (The file name must be the same as the actual one. The following is only an example.) Assume that the package name of the corresponding Java code is SparkOnHbaseJavaExample.jar and the package is saved to the current directory.
bin/spark-submit --master yarn --deploy-mode client --jars SparkOnHbaseJavaExample.jar HBaseStreamingBulkPutExample.py ${ip} 9999 streamingTable cf1
- yarn-cluster mode:
Java/Scala version. (The class name must be the same as the actual code. The following is only an example.) ${ip} must be the IP address of the host where the nc -lk 9999 command is executed.
bin/spark-submit --master yarn --deploy-mode cluster --class com.huawei.bigdata.spark.examples.streaming.JavaHBaseStreamingBulkPutExample --files /opt/user.keytab,/opt/krb5.conf SparkOnHbaseJavaExample.jar ${ip} 9999 streamingTable cf1
Python version. (The file name must be the same as the actual one. The following is only an example.) Assume that the package name of the corresponding Java code is SparkOnHbaseJavaExample.jar and the package is saved to the current directory.
bin/spark-submit --master yarn --deploy-mode cluster --files /opt/user.keytab,/opt/krb5.conf --jars SparkOnHbaseJavaExample.jar HBaseStreamingBulkPutExample.py ${ip} 9999 streamingTable cf1
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; } LoginUtil.loginWithUserKeytab(); 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 = { loginUtil.loginWithUserKeytab() 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] (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. Set spark.yarn.security.credentials.hbase.enabled to true. """ 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 the SparkSession instance. spark.stop()
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