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Spark Node

Overview

Spark task type for executing Spark application. When executing the Spark task, the worker will submits a job to the Spark cluster by following commands:

(1) spark submit method to submit tasks. See spark-submit for more details.

(2) spark sql method to submit tasks. See spark sql for more details.

Create Task

  • Click Project Management -> Project Name -> Workflow Definition, and click the Create Workflow button to enter the DAG editing page.
  • Drag from the toolbar to the canvas.

Task Parameters

Parameter Description
Program type Supports Java, Scala, Python, and SQL.
Spark version Support Spark1 and Spark2.
The class of main function The full path of Main Class, the entry point of the Spark program.
Main jar package The Spark jar package (upload by Resource Center).
SQL scripts SQL statements in .sql files that Spark sql runs.
Deployment mode
  • spark submit supports three modes: yarn-clusetr, yarn-client and local.
  • spark sql supports yarn-client and local modes.
Task name Spark task name.
Driver core number Set the number of Driver core, which can be set according to the actual production environment.
Driver memory size Set the size of Driver memories, which can be set according to the actual production environment.
Number of Executor Set the number of Executor, which can be set according to the actual production environment.
Executor memory size Set the size of Executor memories, which can be set according to the actual production environment.
Main program parameters Set the input parameters of the Spark program and support the substitution of custom parameter variables.
Optional parameters Support --jars, --files,--archives, --conf format.
Resource Appoint resource files in the Resource if parameters refer to them.
Custom parameter It is a local user-defined parameter for Spark, and will replace the content with ${variable} in the script.
Predecessor task Selecting a predecessor task for the current task, will set the selected predecessor task as upstream of the current task.

Task Example

spark submit

Execute the WordCount Program

This is a common introductory case in the big data ecosystem, which often apply to computational frameworks such as MapReduce, Flink and Spark. The main purpose is to count the number of identical words in the input text. (Flink's releases attach this example job)

Configure the Spark Environment in DolphinScheduler

If you are using the Spark task type in a production environment, it is necessary to configure the required environment first. The following is the configuration file: bin/env/dolphinscheduler_env.sh.

spark_configure

Upload the Main Package

When using the Spark task node, you need to upload the jar package to the Resource Centre for the execution, refer to the resource center.

After finish the Resource Centre configuration, upload the required target files directly by dragging and dropping.

resource_upload

Configure Spark Nodes

Configure the required content according to the parameter descriptions above.

demo-spark-simple

Spark sql

Execute DDL and DML statements

This case is to create a view table terms and write three rows of data and a table wc in parquet format and determine whether the table exists. The program type is SQL. Insert the data of the view table terms into the table wc in parquet format.

spark_sql

Note

JAVA and Scala are only used for identification, and there is no difference when you use the Spark task. If your application is developed by Python, you could just ignore the parameter Main Class in the form. Parameter SQL scripts is only for SQL type and could be ignored in JAVA, Scala and Python.

SQL does not currently support cluster mode.