Exception: Java gateway process exited before sending its port number Error when try to run spark cluster in python app

[todhm]

I am trying to create python app which use spark cluster consists with docker.

version: "3.6"
services:

  webapp:
    container_name: webapp
    image: todhm/flask_spark_webapp
    build:
      context: ./flask_with_spark
    working_dir: /app
    command: gunicorn -b 0.0.0.0:8000 --reload -w 4  wsgi:app
    networks:
        - sparknetwork
    ports:
      - "8000:8000"
    volumes:
        - ./flask_with_spark:/app
    depends_on:
      - spark-master
    environment:
     - SPARK_APPLICATION_PYTHON_LOCATION =/app/wsgi.py
     - SPARK_MASTER_NAME=spark-master
     - SPARK_MASTER_PORT=7077

  spark-master:
    image: bde2020/spark-master:2.3.0-hadoop2.7
    container_name: spark-master
    networks:
    - sparknetwork
    ports:
      - "8080:8080"
      - "7077:7077"
    environment:
      - INIT_DAEMON_STEP=setup_spark

  spark-worker-1:
    image: bde2020/spark-worker:2.3.0-hadoop2.7
    container_name: spark-worker-1
    networks:
    - sparknetwork
    depends_on:
      - spark-master
    ports:
      - "8081:8081"
    environment:
      - "SPARK_MASTER=spark://spark-master:7077"

networks:
    sparknetwork:

However when I try to create pyspark app in webapp container with following configuration it gave me some error.

   spark = SparkSession.\
            builder.\
            master("spark://spark-master:7077").\
            config("spark.submit.deployMode", "cluster").\
            config("spark.jars.packages", "org.mongodb.spark:mongo-spark-connector_2.11:2.2.3").\
            config("spark.executor.memory", self.executor_memory).\
            getOrCreate()

Traceback (most recent call last):
  File "/app/spark/tests.py", line 36, in test_write_duplicate_names
    self.sa.return_all_books()
  File "/app/spark/sparkapp.py", line 37, in return_all_books
    self.create_spark_app()
  File "/app/spark/sparkapp.py", line 33, in create_spark_app
    getOrCreate()
  File "/usr/local/lib/python3.4/dist-packages/pyspark/sql/session.py", line 173, in getOrCreate
    sc = SparkContext.getOrCreate(sparkConf)
  File "/usr/local/lib/python3.4/dist-packages/pyspark/context.py", line 343, in getOrCreate
    SparkContext(conf=conf or SparkConf())
  File "/usr/local/lib/python3.4/dist-packages/pyspark/context.py", line 115, in __init__
    SparkContext._ensure_initialized(self, gateway=gateway, conf=conf)
  File "/usr/local/lib/python3.4/dist-packages/pyspark/context.py", line 292, in _ensure_initialized
    SparkContext._gateway = gateway or launch_gateway(conf)
  File "/usr/local/lib/python3.4/dist-packages/pyspark/java_gateway.py", line 93, in launch_gateway
    raise Exception("Java gateway process exited before sending its port number")
Exception: Java gateway process exited before sending its port number

How can I solve this problem?

[sharifgig]

@todhm In my case, this error starting with JAVA_HOME is not set. I tried to save the JAVA_HOME manually but it was not working.

JAVA_HOME is not set
JAVA_HOME is not set
Traceback (most recent call last):
File "run.py", line 1, in <module>
    from app import app
   File "./app/__init__.py", line 6, in <module>
    from app import route
  File "./app/route.py", line 4, in <module>
    from app.resources.recommendation import Recommendation, GetRecommendation, Model
  File "./app/resources/recommendation.py", line 5, in <module>
    from app.core import core
   File "./app/core/core.py", line 15, in <module>
     sc =SparkContext.getOrCreate()
  File "/usr/local/lib/python3.7/site-packages/pyspark/context.py", line 367, in getOrCreate
 Traceback (most recent call last):
  File "run.py", line 1, in <module>
    from app import app
    SparkContext(conf=conf or SparkConf())
  File "./app/__init__.py", line 6, in <module>
  File "/usr/local/lib/python3.7/site-packages/pyspark/context.py", line 133, in __init__
   from app import route
  File "./app/route.py", line 4, in <module>
    SparkContext._ensure_initialized(self, gateway=gateway, conf=conf)
  File "/usr/local/lib/python3.7/site-packages/pyspark/context.py", line 316, in _ensure_initialized
     from app.resources.recommendation import Recommendation, GetRecommendation, Model
   File "./app/resources/recommendation.py", line 5, in <module>
     from app.core import core
  File "./app/core/core.py", line 15, in <module>
    SparkContext._gateway = gateway or launch_gateway(conf)
   File "/usr/local/lib/python3.7/site-packages/pyspark/java_gateway.py", line 46, in launch_gateway
   sc =SparkContext.getOrCreate()
  File "/usr/local/lib/python3.7/site-packages/pyspark/context.py", line 367, in getOrCreate
    return _launch_gateway(conf)
   File "/usr/local/lib/python3.7/site-packages/pyspark/java_gateway.py", line 108, in _launch_gateway
     raise Exception("Java gateway process exited before sending its port number")
 Exception: Java gateway process exited before sending its port number

Has the error been solved?