spark-submit script in Spark’s bin directory is used to launch applications on a cluster. It can use all of Spark’s supported cluster managers through a uniform interface so you don’t have to configure your application especially for each one.
Bundling Your Application’s Dependencies
If your code depends on other projects, you need to package them alongside your application to distribute the code to a Spark cluster. To do this, create an assembly jar (or “uber” jar) containing your code and its dependencies. Both sbt and Maven have assembly plugins.When creating assembly jars, list Spark and Hadoop as
provided dependencies; these need not be bundled since they are provided by the cluster manager at runtime.bin/spark-submit script as shown here while passing your jar.
Python Dependencies
For Python, you can use the--py-files argument of spark-submit to add .py, .zip or .egg files to be distributed with your application. If you depend on multiple Python files we recommend packaging them into a .zip or .egg.
Launching Applications with spark-submit
Once a user application is bundled, it can be launched using thebin/spark-submit script. This script takes care of setting up the classpath with Spark and its dependencies, and can support different cluster managers and deploy modes that Spark supports:
Common Options
The entry point for your application (e.g.
org.apache.spark.examples.SparkPi)The master URL for the cluster (e.g.
spark://23.195.26.187:7077)Whether to deploy your driver on the worker nodes (
cluster) or locally as an external client (client)Arbitrary Spark configuration property in key=value format. For values that contain spaces wrap “key=value” in quotes. Multiple configurations should be passed as separate arguments.
Path to a bundled jar including your application and all dependencies. The URL must be globally visible inside of your cluster, for instance, an
hdfs:// path or a file:// path that is present on all nodes.Arguments passed to the main method of your main class, if any
Deploy Modes
- Client Mode
- Cluster Mode
In
client mode, the driver is launched directly within the spark-submit process which acts as a client to the cluster. The input and output of the application is attached to the console. This mode is especially suitable for applications that involve the REPL (e.g. Spark shell).A common deployment strategy is to submit your application from a gateway machine that is physically co-located with your worker machines (e.g. Master node in a standalone EC2 cluster). In this setup, client mode is appropriate.Example Usage
Here are a few examples of common options:Master URLs
The master URL passed to Spark can be in one of the following formats:| Master URL | Meaning |
|---|---|
local | Run Spark locally with one worker thread (i.e. no parallelism at all) |
local[K] | Run Spark locally with K worker threads (ideally, set this to the number of cores on your machine) |
local[K,F] | Run Spark locally with K worker threads and F maxFailures |
local[*] | Run Spark locally with as many worker threads as logical cores on your machine |
local[*,F] | Run Spark locally with as many worker threads as logical cores on your machine and F maxFailures |
local-cluster[N,C,M] | Local-cluster mode is only for unit tests. It emulates a distributed cluster in a single JVM with N workers, C cores per worker and M MiB of memory per worker |
spark://HOST:PORT | Connect to the given Spark standalone cluster master. The port must be whichever one your master is configured to use, which is 7077 by default |
spark://HOST1:PORT1,HOST2:PORT2 | Connect to the given Spark standalone cluster with standby masters with Zookeeper. The list must have all the master hosts in the high availability cluster |
yarn | Connect to a YARN cluster in client or cluster mode depending on the value of --deploy-mode. The cluster location will be found based on the HADOOP_CONF_DIR or YARN_CONF_DIR variable |
k8s://HOST:PORT | Connect to a Kubernetes cluster in client or cluster mode. The HOST and PORT refer to the Kubernetes API Server. It connects using TLS by default |
Loading Configuration from a File
Thespark-submit script can load default Spark configuration values from a properties file and pass them on to your application. By default, Spark will read options from conf/spark-defaults.conf in the SPARK_HOME directory.
You can specify a custom properties file using the --properties-file parameter:
Loading default Spark configurations this way can obviate the need for certain flags to
spark-submit. For instance, if the spark.master property is set, you can safely omit the --master flag.Configuration Precedence
Configuration values explicitly set on aSparkConf take the highest precedence, then flags passed to spark-submit, then values in the defaults file.
If you are ever unclear where configuration options are coming from, you can print out fine-grained debugging information by running spark-submit with the --verbose option.
Advanced Dependency Management
When usingspark-submit, the application jar along with any jars included with the --jars option will be automatically transferred to the cluster. URLs supplied after --jars must be separated by commas.
URL Schemes
Spark uses the following URL scheme to allow different strategies for disseminating jars:file:// - Driver HTTP Server
file:// - Driver HTTP Server
Absolute paths and
file:/ URIs are served by the driver’s HTTP file server, and every executor pulls the file from the driver HTTP server.hdfs://, http://, https://, ftp:// - Remote Download
hdfs://, http://, https://, ftp:// - Remote Download
These pull down files and JARs from the URI as expected.
local:// - Local File
local:// - Local File
A URI starting with
local:/ is expected to exist as a local file on each worker node. This means that no network IO will be incurred, and works well for large files/JARs that are pushed to each worker, or shared via NFS, GlusterFS, etc.Maven Coordinates
You can also include dependencies by supplying a comma-delimited list of Maven coordinates with--packages. All transitive dependencies will be handled when using this command:
--repositories flag.