Updated on 2024-06-13 GMT+08:00

PySpark Example Code

Development Description

Mongo can be connected only through enhanced datasource connections.

DDS is compatible with the MongoDB protocol.

  • Prerequisites

    An enhanced datasource connection has been created on the DLI management console and bound to a queue in packages.

    Hard-coded or plaintext passwords pose significant security risks. To ensure security, encrypt your passwords, store them in configuration files or environment variables, and decrypt them when needed.

  • Connecting to data sources through DataFrame APIs
    1. Import dependencies.
      from __future__ import print_function
      from pyspark.sql.types import StructType, StructField, IntegerType, StringType
      from pyspark.sql import SparkSession
    2. Create a session.
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      sparkSession = SparkSession.builder.appName("datasource-mongo").getOrCreate()
      
    3. Set connection parameters.
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      url = "192.168.4.62:8635,192.168.5.134:8635/test?authSource=admin"
      uri = "mongodb://username:pwd@host:8635/db"
      user = "rwuser"
      database = "test"
      collection = "test"
      password = "######"
      

      For details about the parameters, see Table 1.

    4. Create a DataFrame.
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      dataList = sparkSession.sparkContext.parallelize([(1, "Katie", 19),(2,"Tom",20)])
      schema = StructType([StructField("id", IntegerType(), False),          
                           StructField("name", StringType(), False),
                           StructField("age", IntegerType(), False)])
      dataFrame = sparkSession.createDataFrame(dataList, schema)
      
    5. Import data to Mongo.
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      dataFrame.write.format("mongo")
        .option("url", url)\
        .option("uri", uri)\
        .option("user",user)\
        .option("password",password)\
        .option("database",database)\
        .option("collection",collection)\
        .mode("Overwrite")\
        .save()
      
    6. Read data from Mongo.
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      jdbcDF = sparkSession.read
        .format("mongo")\
        .option("url", url)\
        .option("uri", uri)\
        .option("user",user)\
        .option("password",password)\
        .option("database",database)\
        .option("collection",collection)\
        .load()
      jdbcDF.show()
      
    7. View the operation result.

  • Connecting to data sources through SQL APIs
    1. Create a table to connect to a Mongo data source.
      sparkSession.sql(
            "create table test_dds(id string, name string, age int) using mongo options(
            'url' = '192.168.4.62:8635,192.168.5.134:8635/test?authSource=admin',
            'uri' = 'mongodb://username:pwd@host:8635/db',
            'database' = 'test',
            'collection' = 'test', 
            'user' = 'rwuser', 
            'password' = '######')")

      For details about the parameters, see Table 1.

    2. Insert data.
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      sparkSession.sql("insert into test_dds values('3', 'Ann',23)")
      
    3. Query data.
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      sparkSession.sql("select * from test_dds").show()
      
  • Submitting a Spark job
    1. Upload the Python code file to DLI.

    2. In the Spark job editor, select the corresponding dependency module and execute the Spark job.

      • If the Spark version is 2.3.2 (will be offline soon) or 2.4.5, specify the Module to sys.datasource.mongo when you submit a job.
      • If the Spark version is 3.1.1, you do not need to select a module. Configure Spark parameters (--conf).

        spark.driver.extraClassPath=/usr/share/extension/dli/spark-jar/datasource/mongo/*

        spark.executor.extraClassPath=/usr/share/extension/dli/spark-jar/datasource/mongo/*

      • For details about how to submit a job on the console, see the description of the table "Parameters for selecting dependency resources" in Creating a Spark Job.
      • For details about how to submit a job through an API, see the description of the modules parameter in Table 2 "Request parameters" in Creating a Batch Processing Job.

Complete Example Code

  • Connecting to data sources through DataFrame APIs
    from __future__ import print_function
    from pyspark.sql.types import StructType, StructField, IntegerType, StringType
    from pyspark.sql import SparkSession
    
    if __name__ == "__main__":
      # Create a SparkSession session.
      sparkSession = SparkSession.builder.appName("datasource-mongo").getOrCreate()
    
      # Create a DataFrame and initialize the DataFrame data.  
      dataList = sparkSession.sparkContext.parallelize([("1", "Katie", 19),("2","Tom",20)])
      
      # Setting schema  
      schema = StructType([StructField("id", IntegerType(), False),StructField("name", StringType(), False), StructField("age", IntegerType(), False)])
    
      # Create a DataFrame from RDD and schema  
      dataFrame = sparkSession.createDataFrame(dataList, schema)
    
      # Setting connection parameters  
      url = "192.168.4.62:8635,192.168.5.134:8635/test?authSource=admin"
      uri = "mongodb://username:pwd@host:8635/db"
      user = "rwuser"
      database = "test"
      collection = "test"
      password = "######"
     
      # Write data to the mongodb table  
      dataFrame.write.format("mongo")
        .option("url", url)\
        .option("uri", uri)\
        .option("user",user)\
        .option("password",password)\
        .option("database",database)\
        .option("collection",collection)
        .mode("Overwrite").save()
    
      # Read data  
      jdbcDF = sparkSession.read.format("mongo")
        .option("url", url)\
        .option("uri", uri)\
        .option("user",user)\
        .option("password",password)\
        .option("database",database)\
        .option("collection",collection)\
        .load()   
      jdbcDF.show()
     
      # close session  
      sparkSession.stop()
  • Connecting to data sources through SQL APIs
    from __future__ import print_function
    from pyspark.sql import SparkSession
    
    if __name__ == "__main__":
      # Create a SparkSession session.  
      sparkSession = SparkSession.builder.appName("datasource-mongo").getOrCreate()
    
      # Create a data table for DLI - associated mongo
        sparkSession.sql(
          "create table test_dds(id string, name string, age int) using mongo options(\
          'url' = '192.168.4.62:8635,192.168.5.134:8635/test?authSource=admin',\
          'uri' = 'mongodb://username:pwd@host:8635/db',\
          'database' = 'test',\
          'collection' = 'test', \
          'user' = 'rwuser', \
          'password' = '######')")
    
      # Insert data into the DLI-table  
      sparkSession.sql("insert into test_dds values('3', 'Ann',23)")
    
      # Read data from DLI-table  
      sparkSession.sql("select * from test_dds").show()
    
      # close session  
      sparkSession.stop()