Command-Line Interface

Flink provides a command-line interface to run programs that are packaged as JAR files, and control their execution. The command line interface is part of any Flink setup, available in local single node setups and in distributed setups. It is located under <flink-home>/bin/flink and connects by default to the running Flink master (JobManager) that was started from the same installation directory.

A prerequisite to using the command line interface is that the Flink master (JobManager) has been started (via <flink-home>/bin/start-local.sh or <flink-home>/bin/start-cluster.sh) or that a YARN environment is available.

The command line can be used to

Examples

  • Run example program with no arguments.

    ./bin/flink run ./examples/batch/WordCount.jar
    
  • Run example program with arguments for input and result files

    ./bin/flink run ./examples/batch/WordCount.jar \
                         --input file:///home/user/hamlet.txt --output file:///home/user/wordcount_out
    
  • Run example program with parallelism 16 and arguments for input and result files

    ./bin/flink run -p 16 ./examples/batch/WordCount.jar \
                         --input file:///home/user/hamlet.txt --output file:///home/user/wordcount_out
    
  • Run example program with flink log output disabled

        ./bin/flink run -q ./examples/batch/WordCount.jar
    
  • Run example program in detached mode

        ./bin/flink run -d ./examples/batch/WordCount.jar
    
  • Run example program on a specific JobManager:

    ./bin/flink run -m myJMHost:6123 \
                           ./examples/batch/WordCount.jar \
                           --input file:///home/user/hamlet.txt --output file:///home/user/wordcount_out
    
  • Run example program with a specific class as an entry point:

    ./bin/flink run -c org.apache.flink.examples.java.wordcount.WordCount \
                           ./examples/batch/WordCount.jar \
                           --input file:///home/user/hamlet.txt --output file:///home/user/wordcount_out
    
  • Run example program using a per-job YARN cluster with 2 TaskManagers:

    ./bin/flink run -m yarn-cluster -yn 2 \
                           ./examples/batch/WordCount.jar \
                           --input hdfs:///user/hamlet.txt --output hdfs:///user/wordcount_out
    
  • Display the optimized execution plan for the WordCount example program as JSON:

    ./bin/flink info ./examples/batch/WordCount.jar \
                            --input file:///home/user/hamlet.txt --output file:///home/user/wordcount_out
    
  • List scheduled and running jobs (including their JobIDs):

    ./bin/flink list
    
  • List scheduled jobs (including their JobIDs):

    ./bin/flink list -s
    
  • List running jobs (including their JobIDs):

    ./bin/flink list -r
    
  • List running Flink jobs inside Flink YARN session:

    ./bin/flink list -m yarn-cluster -yid <yarnApplicationID> -r
    
  • Cancel a job:

    ./bin/flink cancel <jobID>
    
  • Cancel a job with a savepoint:

    ./bin/flink cancel -s [targetDirectory] <jobID>
    
  • Stop a job (streaming jobs only):

    ./bin/flink stop <jobID>
    

The difference between cancelling and stopping a (streaming) job is the following:

On a cancel call, the operators in a job immediately receive a cancel() method call to cancel them as soon as possible. If operators are not not stopping after the cancel call, Flink will start interrupting the thread periodically until it stops.

A “stop” call is a more graceful way of stopping a running streaming job. Stop is only available for jobs which use sources that implement the StoppableFunction interface. When the user requests to stop a job, all sources will receive a stop() method call. The job will keep running until all sources properly shut down. This allows the job to finish processing all inflight data.

Savepoints

Savepoints are controlled via the command line client:

Trigger a Savepoint

./bin/flink savepoint <jobId> [savepointDirectory]

This will trigger a savepoint for the job with ID jobId, and returns the path of the created savepoint. You need this path to restore and dispose savepoints.

Furthermore, you can optionally specify a target file system directory to store the savepoint in. The directory needs to be accessible by the JobManager.

If you don’t specify a target directory, you need to have configured a default directory (see Savepoints). Otherwise, triggering the savepoint will fail.

Trigger a Savepoint with YARN

./bin/flink savepoint <jobId> [savepointDirectory] -yid <yarnAppId>

This will trigger a savepoint for the job with ID jobId and YARN application ID yarnAppId, and returns the path of the created savepoint.

Everything else is the same as described in the above Trigger a Savepoint section.

Cancel with a savepoint

You can atomically trigger a savepoint and cancel a job.

./bin/flink cancel -s  [savepointDirectory] <jobID>

If no savepoint directory is configured, you need to configure a default savepoint directory for the Flink installation (see Savepoints).

The job will only be cancelled if the savepoint succeeds.

Restore a savepoint

./bin/flink run -s <savepointPath> ...

The run command has a savepoint flag to submit a job, which restores its state from a savepoint. The savepoint path is returned by the savepoint trigger command.

By default, we try to match all savepoint state to the job being submitted. If you want to allow to skip savepoint state that cannot be restored with the new job you can set the allowNonRestoredState flag. You need to allow this if you removed an operator from your program that was part of the program when the savepoint was triggered and you still want to use the savepoint.

./bin/flink run -s <savepointPath> -n ...

This is useful if your program dropped an operator that was part of the savepoint.

Dispose a savepoint

./bin/flink savepoint -d <savepointPath>

Disposes the savepoint at the given path. The savepoint path is returned by the savepoint trigger command.

If you use custom state instances (for example custom reducing state or RocksDB state), you have to specify the path to the program JAR with which the savepoint was triggered in order to dispose the savepoint with the user code class loader:

./bin/flink savepoint -d <savepointPath> -j <jarFile>

Otherwise, you will run into a ClassNotFoundException.

Usage

The command line syntax is as follows:

./flink <ACTION> [OPTIONS] [ARGUMENTS]

The following actions are available:

Action "run" compiles and runs a program.

  Syntax: run [OPTIONS] <jar-file> <arguments>
  "run" action options:
     -c,--class <classname>                         Class with the program entry
                                                    point ("main" method or
                                                    "getPlan()" method. Only
                                                    needed if the JAR file does
                                                    not specify the class in its
                                                    manifest.
     -C,--classpath <url>                           Adds a URL to each user code
                                                    classloader  on all nodes in
                                                    the cluster. The paths must
                                                    specify a protocol (e.g.
                                                    file://) and be accessible
                                                    on all nodes (e.g. by means
                                                    of a NFS share). You can use
                                                    this option multiple times
                                                    for specifying more than one
                                                    URL. The protocol must be
                                                    supported by the {@link
                                                    java.net.URLClassLoader}.
     -d,--detached                                  If present, runs the job in
                                                    detached mode
     -m,--jobmanager <host:port>                    Address of the JobManager
                                                    (master) to which to
                                                    connect. Use this flag to
                                                    connect to a different
                                                    JobManager than the one
                                                    specified in the
                                                    configuration.
     -n,--allowNonRestoredState                     Allow non restored savepoint
                                                    state in case an operator has
                                                    been removed from the job.
     -p,--parallelism <parallelism>                 The parallelism with which
                                                    to run the program. Optional
                                                    flag to override the default
                                                    value specified in the
                                                    configuration.
     -q,--sysoutLogging                             If present, suppress logging
                                                    output to standard out.
     -s,--fromSavepoint <savepointPath>             Path to a savepoint to
                                                    restore the job from (for
                                                    example
                                                    hdfs:///flink/savepoint-1537
                                                    ).
     -z,--zookeeperNamespace <zookeeperNamespace>   Namespace to create the
                                                    Zookeeper sub-paths for high
                                                    availability mode

  Options for yarn-cluster mode:
     -yD <arg>                            Dynamic properties
     -yd,--yarndetached                   Start detached
     -yid,--yarnapplicationId <arg>       Attach to running YARN session
     -yj,--yarnjar <arg>                  Path to Flink jar file
     -yjm,--yarnjobManagerMemory <arg>    Memory for JobManager Container [in
                                          MB]
     -yn,--yarncontainer <arg>            Number of YARN container to allocate
                                          (=Number of Task Managers)
     -ynm,--yarnname <arg>                Set a custom name for the application
                                          on YARN
     -yq,--yarnquery                      Display available YARN resources
                                          (memory, cores)
     -yqu,--yarnqueue <arg>               Specify YARN queue.
     -ys,--yarnslots <arg>                Number of slots per TaskManager
     -yst,--yarnstreaming                 Start Flink in streaming mode
     -yt,--yarnship <arg>                 Ship files in the specified directory
                                          (t for transfer)
     -ytm,--yarntaskManagerMemory <arg>   Memory per TaskManager Container [in
                                          MB]
     -yz,--yarnzookeeperNamespace <arg>   Namespace to create the Zookeeper
                                          sub-paths for high availability mode



Action "info" shows the optimized execution plan of the program (JSON).

  Syntax: info [OPTIONS] <jar-file> <arguments>
  "info" action options:
     -c,--class <classname>           Class with the program entry point ("main"
                                      method or "getPlan()" method. Only needed
                                      if the JAR file does not specify the class
                                      in its manifest.
     -p,--parallelism <parallelism>   The parallelism with which to run the
                                      program. Optional flag to override the
                                      default value specified in the
                                      configuration.
  Options for yarn-cluster mode:
     -yid,--yarnapplicationId <arg>   Attach to running YARN session



Action "list" lists running and scheduled programs.

  Syntax: list [OPTIONS]
  "list" action options:
     -m,--jobmanager <host:port>   Address of the JobManager (master) to which
                                   to connect. Use this flag to connect to a
                                   different JobManager than the one specified
                                   in the configuration.
     -r,--running                  Show only running programs and their JobIDs
     -s,--scheduled                Show only scheduled programs and their JobIDs
  Options for yarn-cluster mode:
     -yid,--yarnapplicationId <arg>   Attach to running YARN session



Action "stop" stops a running program (streaming jobs only).

  Syntax: stop [OPTIONS] <Job ID>
  "stop" action options:
     -m,--jobmanager <host:port>   Address of the JobManager (master) to which
                                   to connect. Use this flag to connect to a
                                   different JobManager than the one specified
                                   in the configuration.
  Options for yarn-cluster mode:
     -yid,--yarnapplicationId <arg>   Attach to running YARN session



Action "cancel" cancels a running program.

  Syntax: cancel [OPTIONS] <Job ID>
  "cancel" action options:
     -m,--jobmanager <host:port>            Address of the JobManager (master)
                                            to which to connect. Use this flag
                                            to connect to a different JobManager
                                            than the one specified in the
                                            configuration.
     -s,--withSavepoint <targetDirectory>   Trigger savepoint and cancel job.
                                            The target directory is optional. If
                                            no directory is specified, the
                                            configured default directory
                                            (state.savepoints.dir) is used.
  Options for yarn-cluster mode:
     -yid,--yarnapplicationId <arg>   Attach to running YARN session



Action "savepoint" triggers savepoints for a running job or disposes existing ones.

  Syntax: savepoint [OPTIONS] <Job ID> [<target directory>]
  "savepoint" action options:
     -d,--dispose <arg>            Path of savepoint to dispose.
     -j,--jarfile <jarfile>        Flink program JAR file.
     -m,--jobmanager <host:port>   Address of the JobManager (master) to which
                                   to connect. Use this flag to connect to a
                                   different JobManager than the one specified
                                   in the configuration.
  Options for yarn-cluster mode:
     -yid,--yarnapplicationId <arg>   Attach to running YARN session

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