knaufk commented on a change in pull request #9192: [FLINK-12749] [docs] [examples] Initial Version of Flink Cluster Playground URL: https://github.com/apache/flink/pull/9192#discussion_r308531539
########## File path: docs/getting-started/docker-playgrounds/flink_cluster_playground.md ########## @@ -0,0 +1,680 @@ +--- +title: "Flink Cluster Playground" +nav-title: 'Flink Cluster Playground' +nav-parent_id: docker-playgrounds +nav-pos: 1 +--- +<!-- +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. +--> + +There are many ways to deploy and operate Apache Flink in various environments. Regardless of this +variety, the fundamental building blocks of a Flink Cluster remain the same and similar +operational principles apply. + +This docker compose-based playground will get you started with Apache Flink operations quickly and +will briefly introduce you to the main components that make up a Flink Cluster. + +* This will be replaced by the TOC +{:toc} + +## Anatomy of this Playground + +This playground consists of a long living +[Flink Session Cluster]({{ site.baseurl }}/concepts/glossary.html#flink-session-cluster) and a Kafka +Cluster. + +A Flink Cluster always consists of a +[Flink Master]({{ site.baseurl }}/concepts/glossary.html#flink-master) and one or more +[Flink TaskManagers]({{ site.baseurl }}/concepts/glossary.html#flink-taskmanager). The Flink Master +is responsible to handle Job submissions, the supervision of Jobs as well as resource +management. The Flink TaskManagers are the worker processes and are responsible for the execution of +the actual [Tasks]({{ site.baseurl }}/concepts/glossary.html#task) which make up a Flink Job. In +this playground you will start with a single TaskManager, but scale out to more TaskManagers later. +Additionally, this playground comes with a dedicated *client* container, which we use to submit the +Flink Job initially and to perform various operational tasks later on. + +The Kafka Cluster consists of a Zookeeper server and a Kafka Broker. + +<img src="{{ site.baseurl }}/fig/flink-docker-playground.svg" alt="Flink Docker Playground" +class="offset" width="80%" /> + +When the playground is started a Flink Job called *Flink Event Count* will be submitted to the +Flink Master. Additionally, two Kafka Topics *input* and *output* are created. + +<img src="{{ site.baseurl }}/fig/click-event-count-example.svg" alt="Click Event Count Example" +class="offset" width="80%" /> + +The Job consumes `ClickEvent`s from the *input* topic, each with a `timestamp` and a `page`. The +events are then keyed by `page` and counted in one minute +[windows]({{ site.baseurl }}/dev/stream/operators/windows.html). The results are written to the +*output* topic. + +There are six different `page`s and the **events are generated so that each window contains exactly +one thousand records**. + +{% top %} + +## Setup + +{% if site.version contains "SNAPSHOT" %} +<p style="border-radius: 5px; padding: 5px" class="bg-danger"> + <b>Note</b>: The Apache Flink Docker images used for this playground are only available for + released versions of Apache Flink. Since you are currently looking at the latest SNAPSHOT + version of the documentation the branch referenced below will not exist. You can either change it + manually or switch to the released version of the ocumentation via the release picker. +</p> +{% endif %} + +In this section you will setup the playground locally on your machine and verify that the Job is +running successfully. + +This guide assumes that you have [docker](https://docs.docker.com/) (1.12+) and +[docker-compose](https://docs.docker.com/compose/) (2.1+) installed on your machine. + +The required configuration files are available in the +[flink-playgrounds](https://github.com/apache/flink-playgrounds) repository. Check it out and spin +up the environment: + +{% highlight bash %} +git clone --branch release-{{ site.version }} g...@github.com:apache/flink-playgrounds.git +cd flink-cluster-playground +docker-compose up -d +{% endhighlight %} + +Afterwards, `docker-compose ps` should give you the following output: + +{% highlight bash %} + Name Command State Ports +-------------------------------------------------------------------------------------------------------------------------------- +flink-cluster-playground_clickevent-generator_1 /docker-entrypoint.sh java ... Up 6123/tcp, 8081/tcp +flink-cluster-playground_client_1 /docker-entrypoint.sh flin ... Exit 0 +flink-cluster-playground_jobmanager_1 /docker-entrypoint.sh jobm ... Up 6123/tcp, 0.0.0.0:8081->8081/tcp +flink-cluster-playground_kafka_1 start-kafka.sh Up 0.0.0.0:9094->9094/tcp +flink-cluster-playground_taskmanager_1 /docker-entrypoint.sh task ... Up 6123/tcp, 8081/tcp +flink-cluster-playground_zookeeper_1 /bin/sh -c /usr/sbin/sshd ... Up 2181/tcp, 22/tcp, 2888/tcp, 3888/tcp +{% endhighlight %} + +This indicates that the client container has successfully submitted the Flink Job ("Exit 0") and all +cluster components as well as the data generator are running ("Up"). + +## Interaction with the Playground + +There are many ways to interact with this playground and its components. + +### Flink WebUI + +The Flink WebUI is probably the most natural starting point to observe your Flink Cluster. It is +exposed under `http://localhost:8081`. If everything went well, you'll see that the cluster initially +consists of one TaskManager and one Job called *Click Event Count* is in "RUNNING" state. + +<img src="{{ site.baseurl }}/fig/playground-webui.png" alt="Playground Flink WebUI" +class="offset" width="100%" /> + +### Logs + +**JobManager** + +The JobManager logs can be tailed via `docker-compose`. + +{% highlight bash %} +docker-compose logs -f jobmanager +{% endhighlight %} + +After the initial startup you should mainly see log messages for every checkpoint completion. + +**TaskManager** + +The TaskManager log can be tailed in the same way. +{% highlight bash %} +docker-compose logs -f taskmanager +{% endhighlight %} + +After the initial startup you should mainly see log messages for every checkpoint completion. + +### Flink CLI + +The [Flink CLI]({{ site.baseurl }}/ops/cli.html) can be used from within the client container. For +example, to print the `help` message of the Flink CLI you can run +{% highlight bash%} +docker-compose run --no-deps client flink --help +{% endhighlight %} + +### Flink REST API + +The [Flink REST API]({{ site.baseurl }}/monitoring/rest_api.html#api) is exposed via +`localhost:8081` on the host or via `jobmanager:8081` from the client container, e.g. to list all +currently running jobs, you can run: +{% highlight bash%} +docker-compose run --no-deps client curl jobmanager:8081/jobs +{% endhighlight %} + +### Kafka Topics + +To manually look at the records in the Kakfa Topics, you can run +{% highlight bash%} +//input topic (1000 records/s) +docker-compose exec kafka kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic input +//output topic (6 records/min) +docker-compose exec kafka kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic output +{% endhighlight %} + +{% top %} + +## Tear Down + +To tear down the environment (including the removal of all volumes) run: +{% highlight bash%} +docker-compose down -v +{% endhighlight %} + +{% top %} + +## Operational Plays Review comment: I went with "Time to Play". ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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