gradiant/spark repository overview

This is a docker image of Apache Spark⁠.

⁠Properties

• This image has a small footprint ( base docker image is openjdk:8u171-jre-alpine3.8).
• This image has Kafka libraries included.
• There is a derived image with pyspark support gradiant/spark:2.4.0-python
• There is a derived image with sparkR support gradiant/spark:2.4.0-R

⁠Howto

The image can be used to run spark in serveral ways:

• Image to use for run spark locally.
• Image to deploy spark standalone (master and workers).
• Image to run a spark client.
• Image to use for spark on kubernetes.

⁠Local Spark

Example of running a spark job in the container's local spark.

docker run -ti gradiant/spark:2.4.0 spark-submit \
  --master spark://spark-master:7077local[*] \
  --class org.apache.spark.examples.SparkPi $SPARK_HOME/examples/jars/spark-examples_2.11-2.4.0.jar 100

⁠Spark Standalone

master container

run container with standalone master as command.

docker run -d gradiant/spark standalone master

Optional configuration is through environment variables:

• SPARK_MASTER_HOST Default is the container hostname)
• SPARK_MASTER_PORT (optional. Default is 7077)
• SPARK_MASTER_WEBUI_PORT (optional. Default is 8080)

worker container

run container with standalone worker <master_url> as command.

docker run -d gradiant/spark standalone worker <master_url> [options]
Master must be a URL of the form spark://hostname:port.
Options:
  -c CORES, --cores CORES  Number of cores to use
  -m MEM, --memory MEM     Amount of memory to use (e.g. 1000M, 2G)

Optional configuration through environment variables:

• SPARK_WORKER_PORT The port number for the worker. If unset, Spark will find a valid port number, but with no guarantee of a predictable pattern.
• SPARK_WORKER_WEBUI_PORT The port for the web interface of the worker. Default is 8081.

Example of standalone usage

Example of a local spark standalone deployment with a spark master and three spark worker just for testing purposes.

We strongly advise the deployment of spark in a cluster through an Infrastructure Orchestrator such as Swarm or Kubernetes to avoid worker containers to share resources.

docker network create sparknet
docker run -d -p 8080:8080 --name spadockerrk-master gradiant/spark standalone master
docker run -d --net sparknet --name spark-worker1 gradiant/spark:2.4.0 standalone worker spark://spark-master:7077
docker run -d --net sparknet --name spark-worker2 gradiant/spark:2.4.0 standalone worker spark://spark-master:7077
docker run -d --net sparknet --name spark-worker3 gradiant/spark:2.4.0 standalone worker spark://spark-master:7077

⁠Spark Client

Example of running a container as spark client to submit a job to the previous standalone spark:

docker run -ti --net sparknet --rm gradiant/spark:2.4.0 spark-submit \
  --master spark://spark-master:7077 \
  --class org.apache.spark.examples.SparkPi $SPARK_HOME/examples/jars/spark-examples_2.11-2.4.0.jar 100

⁠Spark on Kubernetes

Official documentation⁠

Example of submiting a spark job to a kubernetes cluster with the gradiant/spark:2.4.0 docker image.

⁠Prerequisites

• A kubernetes cluster (tested on kubernetes 1.11.8)

• Setting up a kubernetes serviceaccount with permissions to create pods and services:

kubectl create serviceaccount spark
kubectl create rolebinding spark-role --clusterrole=edit --serviceaccount=default:spark --namespace=default

We setup local proxy to the Kubernetes API:

kubectl proxy

Now kubernetes API is accessible at http://127.0.0.1:8001⁠

We run a container as spark client and point to the kubernetes API as spark scheduler:

docker run --rm -ti --net host gradiant/spark:2.4.0 spark-submit \
    --master k8s://http://127.0.0.1:8001 \
    --deploy-mode cluster \
    --name spark-pi \
    --class org.apache.spark.examples.SparkPi \
    --conf spark.executor.instances=2 \
    --conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
    --conf spark.kubernetes.container.image=gradiant/spark:2.4.0 \
    --conf spark.kubernetes.executor.request.cores=0.2 \
    --executor-memory 500M \
    $SPARK_HOME/examples/jars/spark-examples_2.11-2.4.0.jar 100

We can check the driver pod of the pi application is deployed in kubernetes dashboard:

We can check the log at the driver pod output:

Note: the previous spark-submit configuration is set up for testing

request.cores and executor-memory is set to low values to start the job even in a kubernetes cluster with low available resources