Using Amazon Glue with Flink

Amazon EMR on EKS with Apache Flink releases 6.15.0 and higher supports using the Amazon Glue Data Catalog as a metadata store for streaming and batch SQL workflows.

You must first create an Amazon Glue database named default that serves as your Flink SQL Catalog. This Flink Catalog stores metadata such as databases, tables, paritions, views, functions, and other information needed to access data in other external systems.

aws glue create-database \
    --database-input "{\"Name\":\"default\"}" 

To enable Amazon Glue support, use a FlinkDeployment spec. This example spec uses a Python script to quickly issue some Flink SQL statements to interact with the Amazon Glue catalog.

apiVersion: flink.apache.org/v1beta1
kind: FlinkDeployment
metadata:
  name: python-example
spec:
  flinkVersion: v1_17
  flinkConfiguration:
    taskmanager.numberOfTaskSlots: "1"
    aws.glue.enabled: "true"
  executionRoleArn: job-execution-role-arn;
  emrReleaseLabel: "emr-6.15.0-flink-latest"
  jobManager:
    highAvailabilityEnabled: false
    replicas: 1
    resource:
      memory: "2048m"
      cpu: 1
  taskManager:
    resource:
      memory: "2048m"
      cpu: 1
  job:
    jarURI: s3://<S3_bucket_with_your_script/pyflink-glue-script.py
    entryClass: "org.apache.flink.client.python.PythonDriver"
    args: ["-py", "/opt/flink/usrlib/pyflink-glue-script.py"] 
    parallelism: 1
    upgradeMode: stateless

The following is an example of what your PyFlink script might look like.

import logging
import sys
from pyflink.datastream import StreamExecutionEnvironment
from pyflink.table import StreamTableEnvironment

def glue_demo():
    env = StreamExecutionEnvironment.get_execution_environment()
    t_env = StreamTableEnvironment.create(stream_execution_environment=env)
    t_env.execute_sql("""
          CREATE CATALOG glue_catalog WITH (
          'type' = 'hive',
          'default-database' = 'default',
          'hive-conf-dir' = '/glue/confs/hive/conf',
          'hadoop-conf-dir' = '/glue/confs/hadoop/conf'
          )
                      """)
    t_env.execute_sql("""
          USE CATALOG glue_catalog;
                      """)
    t_env.execute_sql("""
          DROP DATABASE IF EXISTS eks_flink_db CASCADE;
                      """)
    t_env.execute_sql("""
          CREATE DATABASE IF NOT EXISTS eks_flink_db WITH ('hive.database.location-uri'= 's3a://S3-bucket-to-store-metadata/flink/flink-glue-for-hive/warehouse/');
                      """)
    t_env.execute_sql("""
          USE eks_flink_db;
                  """)
    t_env.execute_sql("""
          CREATE TABLE IF NOT EXISTS eksglueorders (
            order_number BIGINT,
            price        DECIMAL(32,2),
            buyer        RO first_name STRING, last_name STRING,
            order_time   TIMESTAMP(3)
          ) WITH (
            'connector' = 'datagen'
          );
                      """)
    t_env.execute_sql("""
          CREATE TABLE IF NOT EXISTS eksdestglueorders (
            order_number BIGINT,
            price        DECIMAL(32,2),
            buyer        ROW first_name STRING, last_name STRING,
            order_time   TIMESTAMP(3)
          ) WITH (
            'connector' = 'filesystem',
            'path' = 's3://S3-bucket-to-store-metadata/flink/flink-glue-for-hive/warehouse/eksdestglueorders',
            'format' = 'json'
          );
                  """)
    t_env.execute_sql("""
          CREATE TABLE IF NOT EXISTS print_table (
            order_number BIGINT,
            price        DECIMAL(32,2),
            buyer        ROW first_name STRING, last_name STRING,
            order_time   TIMESTAMP(3)
          ) WITH (
            'connector' = 'print'
          );
                """)
    t_env.execute_sql("""
          EXECUTE STATEMENT SET
          BEGIN
          INSERT INTO eksdestglueorders SELECT * FROM  eksglueorders LIMIT 10;
          INSERT INTO print_table SELECT * FROM eksdestglueorders;
          END;
            """)


if __name__ == '__main__':
    logging.basicConfig(stream=sys.stdout, level=logging.INFO, format="%(message)s")
    glue_demo()