Github user zentol commented on a diff in the pull request: https://github.com/apache/flink/pull/6239#discussion_r199592285 --- Diff: jepsen-flink/README.md --- @@ -0,0 +1,60 @@ +# jepsen.flink + +A Clojure project based on the [Jepsen](https://github.com/jepsen-io/jepsen) framework to find bugs in the +distributed coordination of Apache Flink®. + +## Test Coverage +Jepsen is a framework built to test the behavior of distributed systems +under faults. The tests in this particular project deploy Flink on either YARN or Mesos, submit a +job, and examine the availability of the job after injecting faults. +A job is said to be available if all the tasks of the job are running. +The faults that can be currently introduced to the Flink cluster include: +* Killing of TaskManager/JobManager processes +* Stopping HDFS NameNode +* Network partitions + +There are many more properties other than job availability that could be +verified but are not yet covered by this test suite, e.g., end-to-end exactly-once processing +semantics. + +## Usage +See the [Jepsen documentation](https://github.com/jepsen-io/jepsen#setting-up-a-jepsen-environment) +for how to set up the environment to run tests. The `scripts/run-tests.sh` documents how to invoke +tests. The Flink job used for testing is located under +`flink-end-to-end-tests/flink-datastream-allround-test`. You have to build the job first and copy +the resulting jar (`DataStreamAllroundTestProgram.jar`) to the `./bin` directory of this project's +root. + +To simplify development, we have prepared Dockerfiles and a Docker Compose template +so that you can run the tests locally in containers. To build the images +and start the containers, simply run: + + $ cd docker + $ ./up.sh + +After the containers started, open a new terminal window and run `docker exec -it jepsen-control bash`. +This will allow you to run arbitrary commands on the control node. +To start the tests, you can use the `run-tests.sh` script in the `docker` directory, +which expects the number of test iterations, and a URI to a Flink distribution, e.g., + + ./docker/run-tests.sh 1 https://example.com/flink-dist.tgz + +The project's root is mounted as a volume to all containers under the path `/jepsen`. +This means that changes to the test sources are immediately reflected in the control node container. +Moreover, this allows you to test locally built Flink distributions by copying the tarball to the +project's root and passing a URI with the `file://` scheme to the `run-tests.sh` script, e.g., +`file:///jepsen/flink-dist.tgz`. + +### Checking the output of tests + +Consult the `jepsen.log` file for the particular test run in the `store` folder. The final output of every test will be either + + Everything looks good! ã½('ã¼`)ã --- End diff -- it's a smiley...
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