An Apache Spark container image. The image is meant to be used for creating an standalone cluster with multiple workers.
This image contains a script named
start-spark (included in the PATH). This script is used to initialize the master and the workers.
The custom commands require an HDFS user to be set. The user's name if read from the
HDFS_USER environment variable and the user is automatically created by the commands.
Starting a master
To start a master run the following command:
Starting a worker
To start a worker run the following command:
start-spark worker [MASTER]
worker from previous versions of the image are maintained for compatibility but should not be used.
Creating a Cluster with Docker Compose
The easiest way to create a standalone cluster with this image is by using Docker Compose. The following snippet can be used as a
docker-compose.yml for a simple cluster:
version: "2" services: master: image: singularities/spark command: start-spark master hostname: master ports: - "6066:6066" - "7070:7070" - "8080:8080" - "50070:50070" worker: image: singularities/spark command: start-spark worker master environment: SPARK_WORKER_CORES: 1 SPARK_WORKER_MEMORY: 2g links: - master
The image has a volume mounted at
/opt/hdfs. To maintain states between restarts, mount a volume at this location. This should be done for the master and the workers.
If you wish to increase the number of workers scale the
worker service by running the
scale command like follows:
docker-compose scale worker=2
The workers will automatically register themselves with the master.