XComp commented on a change in pull request #14287: URL: https://github.com/apache/flink/pull/14287#discussion_r538216240
########## File path: docs/deployment/cli.md ########## @@ -23,664 +23,303 @@ specific language governing permissions and limitations under the License. --> -Flink provides a Command-Line Interface (CLI) to run programs that are packaged -as JAR files, and control their execution. The CLI 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 JobManager that was -started from the same installation directory. - -The command line can be used to - -- submit jobs for execution, -- cancel a running job, -- provide information about a job, -- list running and waiting jobs, -- trigger and dispose savepoints - -A prerequisite to using the command line interface is that the Flink -master (JobManager) has been started (via -`<flink-home>/bin/start-cluster.sh`) or that another deployment target such as YARN or Kubernetes is -available. - -### Deployment targets - -Flink has the concept of executors for defining available deployment targets. You can see the -available executors in the output of `bin/flink --help`, for example: - -``` -Options for Generic CLI mode: - -D <property=value> Generic configuration options for - execution/deployment and for the configured executor. - The available options can be found at - https://ci.apache.org/projects/flink/flink-docs-stabl - e/deployment/config.html - -t,--target <arg> The deployment target for the given application, - which is equivalent to the "execution.target" config - option. The currently available targets are: - "remote", "local", "kubernetes-session", "yarn-per-job", - "yarn-session", "yarn-application" and "kubernetes-application". -``` - -When running one of the `bin/flink` actions, the executor is specified using the `--executor` -option. - - +Flink provides a Command-Line Interface (CLI) `bin/flink` to run programs that +are packaged as JAR files and to control their execution. The CLI is part of any +Flink setup, available in local single node setups and in distributed setups. +It connects to the running JobManager specified in `conf/flink-config.yaml`. * This will be replaced by the TOC {:toc} -## Examples -### Job Submission Examples ------------------------------ - -These examples about how to submit a job in CLI. -<div class="codetabs" markdown="1"> -<div data-lang="java" markdown="1"> - -- 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 in detached mode: - - ./bin/flink run -d ./examples/batch/WordCount.jar - -- Run example program on a specific JobManager: - - ./bin/flink run -m myJMHost:8081 \ - ./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]({% link deployment/resource-providers/yarn.md %}#run-a-single-flink-job-on-hadoop-yarn) with 2 TaskManagers: - - ./bin/flink run -m yarn-cluster \ - ./examples/batch/WordCount.jar \ - --input hdfs:///user/hamlet.txt --output hdfs:///user/wordcount_out +## Job Lifecycle Management -</div> - -<div data-lang="python" markdown="1"> - -<span class="label label-info">Note</span> When submitting Python job via `flink run`, Flink will run the command “python”. Please run the following command to confirm that the command “python” in current environment points to a specified Python version 3.5, 3.6, 3.7 or 3.8: +A prerequisite for the commands listed in this section to work is to have a running Flink deployment +like [Kubernetes]({% link deployment/resource-providers/native_kubernetes.md %}), +[YARN]({% link deployment/resource-providers/yarn.md %}) or any other option available. Feel free to +[start a Flink cluster locally]({% link deployment/resource-providers/standalone/local.md %}#start-a-local-flink-cluster) +to try the commands on your own machine. + +### Submitting a Job +Submitting a job means uploading the job's JAR and related dependencies to the Flink cluster and +initiating the job execution. For the sake of this example, we select a long-running job like +`examples/streaming/StateMachineExample.jar`. Feel free to select any other JAR archive from the +`examples/` folder or deploy your own job. {% highlight bash %} -$ python --version -# the version printed here must be 3.5, 3.6, 3.7 or 3.8 +$ ./bin/flink run \ + --detached \ + ./examples/streaming/StateMachineExample.jar {% endhighlight %} - -- Run Python Table program: - - ./bin/flink run -py examples/python/table/batch/word_count.py - -- Run Python Table program with pyFiles: - - ./bin/flink run -py examples/python/table/batch/word_count.py \ - -pyfs file:///user.txt,hdfs:///$namenode_address/username.txt - -- Run Python Table program with a JAR file: - - ./bin/flink run -py examples/python/table/batch/word_count.py -j <jarFile> - -- Run Python Table program with pyFiles and pyModule: - - ./bin/flink run -pym batch.word_count -pyfs examples/python/table/batch - -- Run Python Table program with parallelism 16: - - ./bin/flink run -p 16 -py examples/python/table/batch/word_count.py - -- Run Python Table program with flink log output disabled: - - ./bin/flink run -q -py examples/python/table/batch/word_count.py - -- Run Python Table program in detached mode: - - ./bin/flink run -d -py examples/python/table/batch/word_count.py - -- Run Python Table program on a specific JobManager: - - ./bin/flink run -m myJMHost:8081 \ - -py examples/python/table/batch/word_count.py - -- Run Python Table program using a [per-job YARN cluster]({% link deployment/resource-providers/yarn.md %}#run-a-single-flink-job-on-hadoop-yarn) with 2 TaskManagers: - - ./bin/flink run -m yarn-cluster \ - -py examples/python/table/batch/word_count.py -</div> - -### Job Management Examples ------------------------------ - -These examples about how to manage a job in CLI. - -- 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 all existing jobs (including their JobIDs): - - ./bin/flink list -a - -- 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 (deprecated; use "stop" instead): - - ./bin/flink cancel -s [targetDirectory] <jobID> - -- Gracefully stop a job with a savepoint (streaming jobs only): - - ./bin/flink stop [-p targetDirectory] [-d] <jobID> - -### Savepoints - -[Savepoints]({% link ops/state/savepoints.md %}) are controlled via the command line client: - -#### Trigger a Savepoint - +Submitting the job using `--detached` will make the command return after the submission is done. +The output contains (besides other things) the ID of the newly submitted job. +``` +Usage with built-in data generator: StateMachineExample [--error-rate <probability-of-invalid-transition>] [--sleep <sleep-per-record-in-ms>] +Usage with Kafka: StateMachineExample --kafka-topic <topic> [--brokers <brokers>] +Options for both the above setups: + [--backend <file|rocks>] + [--checkpoint-dir <filepath>] + [--async-checkpoints <true|false>] + [--incremental-checkpoints <true|false>] + [--output <filepath> OR null for stdout] + +Using standalone source with error rate 0.000000 and sleep delay 1 millis + +Job has been submitted with JobID cca7bc1061d61cf15238e92312c2fc20 +``` +The usage information printed lists job-related parameters that can be added to the end of the job +submission command if necessary. For the purpose of readability, we assume that the returned JobID is +stored in a variable `JOB_ID` for the commands below: {% highlight bash %} -./bin/flink savepoint <jobId> [savepointDirectory] +$ export JOB_ID="cca7bc1061d61cf15238e92312c2fc20" {% endhighlight %} -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. - +There is another action called `run-application` available to run the job in +[Application Mode]({% link deployment/index.md %}#deployment-modes). This documentation does not address +this action individually as it works similarly to the `run` action in terms of the CLI frontend. -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]({% link ops/state/savepoints.md %}#configuration). Otherwise, triggering the savepoint will fail. - -#### Trigger a Savepoint with YARN +### Job Monitoring +You can monitor any running jobs using the `list` action: {% highlight bash %} -./bin/flink savepoint <jobId> [savepointDirectory] -yid <yarnAppId> +$ ./bin/flink list {% endhighlight %} +``` +Waiting for response... +------------------ Running/Restarting Jobs ------------------- +30.11.2020 16:02:29 : cca7bc1061d61cf15238e92312c2fc20 : State machine job (RUNNING) +-------------------------------------------------------------- +No scheduled jobs. +``` +Jobs that were submitted but not started, yet, would be listed under "Scheduled Jobs". -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. - -#### Stop - -Use the `stop` to gracefully stop a running streaming job with a savepoint. +### Creating a Savepoint +[Savepoints]({% link ops/state/savepoints.md %}) can be created to save the current state a job is in. All that's needed is the JobID: {% highlight bash %} -./bin/flink stop [-p targetDirectory] [-d] <jobID> +$ ./bin/flink savepoint \ + $JOB_ID \ + /tmp/flink-savepoints {% endhighlight %} +``` +Triggering savepoint for job cca7bc1061d61cf15238e92312c2fc20. +Waiting for response... +Savepoint completed. Path: file:/tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab +You can resume your program from this savepoint with the run command. +``` +The savepoint folder is optional and needs to be specified if +[state.savepoints.dir]({% link deployment/config.md %}#state-savepoints-dir) isn't set. -A "stop" call is a more graceful way of stopping a running streaming job, as the "stop" signal flows from -source to sink. When the user requests to stop a job, all sources will be requested to send the last checkpoint barrier -that will trigger a savepoint, and after the successful completion of that savepoint, they will finish by calling their -`cancel()` method. If the `-d` flag is specified, then a `MAX_WATERMARK` will be emitted before the last checkpoint -barrier. This will result all registered event-time timers to fire, thus flushing out any state that is waiting for -a specific watermark, e.g. windows. The job will keep running until all sources properly shut down. This allows the - job to finish processing all in-flight data. - +The path to the savepoint can be used later on to [restart the Flink job](#starting-a-job-from-a-savepoint). -#### Cancel with a savepoint (deprecated) +#### Disposing a Savepoint -You can atomically trigger a savepoint and cancel a job. +The `savepoint` action can be also used to remove savepoints. `--dispose` with the corresponding +savepoint path needs to be added: +{% highlight bash %} +$ ./bin/flink savepoint \ + --dispose \ + /tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab \ + $JOB_ID +{% endhighlight %} +``` +Disposing savepoint '/tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab'. +Waiting for response... +Savepoint '/tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab' disposed. +``` +If you use custom state instances (for example custom reducing state or RocksDB state), you have to +specify the path to the program JAR with which the savepoint was triggered. Otherwise, you will run +into a `ClassNotFoundException`: {% highlight bash %} -./bin/flink cancel -s [savepointDirectory] <jobID> +$ ./bin/flink savepoint \ + -d <savepointPath> \ + -j <jarFile> {% endhighlight %} -If no savepoint directory is configured, you need to configure a default savepoint directory for the Flink installation (see [Savepoints]({% link ops/state/savepoints.md %}#configuration)). +Triggering the savepoint disposal through the `savepoint` action does not only remove the data from +the storage but makes Flink clean up the savepoint-related metadata as well. -The job will only be cancelled if the savepoint succeeds. +### Terminating a Job -<p style="border-radius: 5px; padding: 5px" class="bg-danger"> - <b>Note</b>: Cancelling a job with savepoint is deprecated. Use "stop" instead. -</p> +#### Stopping a Job Gracefully Creating a Final Savepoint -#### Restore a savepoint +Another action for stopping a job is `stop`. It is a more graceful way of stopping a running streaming +job as the `stop` flows from source to sink. When the user requests to stop a job, all sources will +be requested to send the last checkpoint barrier that will trigger a savepoint, and after the successful +completion of that savepoint, they will finish by calling their `cancel()` method. {% highlight bash %} -./bin/flink run -s <savepointPath> ... +$ ./bin/flink stop \ + --savepointPath /tmp-flink-savepoints \ + $JOB_ID {% endhighlight %} +``` +Suspending job "cca7bc1061d61cf15238e92312c2fc20" with a savepoint. +Savepoint completed. Path: file:/tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab +``` +We have to use `--savepointPath` to specify the savepoint folder if +[state.savepoints.dir]({% link deployment/config.md %}#state-savepoints-dir) isn't set. -The run command has a savepoint flag to submit a job, which restores its state from a savepoint. The savepoint path is returned by the savepoint trigger command. +If the `--drain` flag is specified, then a `MAX_WATERMARK` will be emitted before the last checkpoint +barrier. This will result all registered event-time timers to fire, thus flushing out any state that +is waiting for a specific watermark, e.g. windows. The job will keep running until all sources properly +shut down. This allows the job to finish processing all in-flight data. -By default, we try to match all savepoint state to the job being submitted. If you want to allow to skip savepoint state that cannot be restored with the new job you can set the `allowNonRestoredState` flag. You need to allow this if you removed an operator from your program that was part of the program when the savepoint was triggered and you still want to use the savepoint. +#### Cancelling a Job Ungracefully +Cancelling a job can be achieved through the `cancel` action: {% highlight bash %} -./bin/flink run -s <savepointPath> -n ... +$ ./bin/flink cancel $JOB_ID {% endhighlight %} +``` +Cancelling job cca7bc1061d61cf15238e92312c2fc20. +Cancelled job cca7bc1061d61cf15238e92312c2fc20. +``` +The corresponding job's state will be transitioned from `Running` to `Cancelled`. Any computations +will be stopped. -This is useful if your program dropped an operator that was part of the savepoint. +<p style="border-radius: 5px; padding: 5px" class="bg-danger"> + <b>Note</b>: The <code class="highlighter-rouge">--withSavepoint</code> flag allows creating a + savepoint as part of the job cancellation. This feature is deprecated. Use the + <a href="#stopping-a-job-gracefully-creating-a-final-savepoint">stop</a> action instead. +</p> -#### Dispose a savepoint +### Starting a Job from a Savepoint +Starting a job from a savepoint can be achieved using the `run` (and `run-application`) action. {% highlight bash %} -./bin/flink savepoint -d <savepointPath> +$ ./bin/flink run \ + --detached \ + --fromSavepoint /tmp/flink-savepoints/savepoint-cca7bc-bb1e257f0dab \ + ./examples/streaming/StateMachineExample.jar {% endhighlight %} +``` +Usage with built-in data generator: StateMachineExample [--error-rate <probability-of-invalid-transition>] [--sleep <sleep-per-record-in-ms>] +Usage with Kafka: StateMachineExample --kafka-topic <topic> [--brokers <brokers>] +Options for both the above setups: + [--backend <file|rocks>] + [--checkpoint-dir <filepath>] + [--async-checkpoints <true|false>] + [--incremental-checkpoints <true|false>] + [--output <filepath> OR null for stdout] + +Using standalone source with error rate 0.000000 and sleep delay 1 millis + +Job has been submitted with JobID 97b20a0a8ffd5c1d656328b0cd6436a6 +``` -Disposes the savepoint at the given path. The savepoint path is returned by the savepoint trigger command. +See how the command is equal to the [initial run command](#submitting-a-job) except for the +`--fromSavepoint` parameter which is used to refer to the state of the +[previously cancelled job](#stopping-a-job-gracefully-creating-a-final-savepoint). A new JobID is +generated that can be used to maintain the job. -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: +By default, we try to match the whole 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. {% highlight bash %} -./bin/flink savepoint -d <savepointPath> -j <jarFile> +$ ./bin/flink run \ + --fromSavepoint <savepointPath> \ + --allowNonRestoredState ... {% endhighlight %} +This is useful if your program dropped an operator that was part of the savepoint. -Otherwise, you will run into a `ClassNotFoundException`. +{% top %} -## Usage +## CLI Actions + +Here's an overview of actions supported by Flink's CLI tool: +<table class="table table-bordered"> + <thead> + <tr> + <th class="text-left" style="width: 25%">Action</th> + <th class="text-left" style="width: 50%">Purpose</th> + </tr> + </thead> + <tbody> + <tr> + <td><code class="highlighter-rouge">run</code></td> + <td> + This action executes jobs. It requires at least the jar containing the job. Flink- + or job-related arguments can be passed if necessary. + </td> + </tr> + <tr> + <td><code class="highlighter-rouge">run-application</code></td> + <td> + This action executes jobs in <a href="{% link deployment/index.md %}#deployment-modes"> + Application Mode</a>. Other than that, it requires the same parameters as the + <code class="highlighter-rouge">run</code> action. + </td> + </tr> + <tr> + <td><code class="highlighter-rouge">info</code></td> Review comment: I considered the `info` action being for more advanced users. The CLI job lifecycle management addresses beginners instead. That was the reason I didn't add it to the `Job Lifecycle Management` section. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
