Exploring Apache Flink with HDP
Apache Flink is an open source platform for distributed stream and batch data processing. More details on Flink and how it is being used in the industry today available here: http://flink-forward.org/?post_type=session. There are a few ways you can explore Flink on HDP 2.3:
1. Compilation on HDP 2.3.2
To compile Flink from source on HDP 2.3 you can use these commands:
curl -o /etc/yum.repos.d/epel-apache-maven.repo https://repos.fedorapeople.org/repos/dchen/apache-maven/epel-apache-maven.repo yum -y install apache-maven-3.2* git clone https://github.com/apache/flink.git cd flink mvn clean install -DskipTests -Dhadoop.version=2.7.1.2.3.2.0-2950 -Pvendor-repos
Note that with this option I ran into a classpath bug and raised it here: https://issues.apache.org/jira/browse/FLINK-3032
2. Run using precompiledtarball
wget http://www.gtlib.gatech.edu/pub/apache/flink/flink-0.9.1/flink-0.9.1-bin-hadoop27.tgz tar xvzf flink-0.9.1-bin-hadoop27.tgzcd flink-0.9.1 export HADOOP_CONF_DIR=/etc/hadoop/conf./bin/yarn-session.sh -n 1 -jm 768 -tm 1024
3. Using Ambari service (demo purposes only for now)
The Ambari service lets you easily install/compile Flink on HDP 2.3
- Features:
- By default, downloads prebuilt package of Flink 0.9.1, but also gives option to build the latest Flink from source instead
- Exposes flink-conf.yaml in Ambari UI
Setup
- Download HDP 2.3 sandbox VM image (Sandbox_HDP_2.3_1_VMware.ova) from Hortonworks website
- Import Sandbox_HDP_2.3_1_VMware.ova into VMWare and set the VM memory size to 8GB
- Now start the VM
- After it boots up, find the IP address of the VM and add an entry into your machines hosts file. For example:
192.168.191.241 sandbox.hortonworks.com sandbox
- Note that you will need to replace the above with the IP for your own VM
- Connect to the VM via SSH (password hadoop)
ssh root@sandbox.hortonworks.com
- To download the Flink service folder, run below
VERSION=`hdp-select status hadoop-client | sed 's/hadoop-client - \([0-9]\.[0-9]\).*/\1/'` sudo git clone https://github.com/abajwa-hw/ambari-flink-service.git /var/lib/ambari-server/resources/stacks/HDP/$VERSION/services/FLINK
- Restart Ambari
#sandbox service ambari restart #non sandbox sudo service ambari-server restart
- Then you can click on 'Add Service' from the 'Actions' dropdown menu in the bottom left of the Ambari dashboard:
On bottom left -> Actions -> Add service -> check Flink server -> Next -> Next -> Change any config you like (e.g. install dir, memory sizes, num containers or values in flink-conf.yaml) -> Next -> Deploy
- By default:
- Container memory is 1024 MB
- Job manager memory of 768 MB
- Number of YARN container is 1
- On successful deployment you will see the Flink service as part of Ambari stack and will be able to start/stop the service from here:
- You can see the parameters you configured under 'Configs' tab
- One benefit to wrapping the component in Ambari service is that you can now monitor/manage this service remotely via REST API
export SERVICE=FLINK export PASSWORD=admin export AMBARI_HOST=localhost #detect name of cluster output=`curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' http://$AMBARI_HOST:8080/api/v1/clusters` CLUSTER=`echo $output | sed -n 's/.*"cluster_name" : "\([^\"]*\)".*/\1/p'` #get service status curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' -X GET http://$AMBARI_HOST:8080/api/v1/clusters/$CLUSTER/services/$SERVICE #start service curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' -X PUT -d '{"RequestInfo": {"context" :"Start $SERVICE via REST"}, "Body": {"ServiceInfo": {"state": "STARTED"}}}' http://$AMBARI_HOST:8080/api/v1/clusters/$CLUSTER/services/$SERVICE #stop service curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' -X PUT -d '{"RequestInfo": {"context" :"Stop $SERVICE via REST"}, "Body": {"ServiceInfo": {"state": "INSTALLED"}}}' http://$AMBARI_HOST:8080/api/v1/clusters/$CLUSTER/services/$SERVICE
- ...and also install via Blueprint. See example here on how to deploy custom services via Blueprints
Use Flink
- Run word count job
su flink export HADOOP_CONF_DIR=/etc/hadoop/conf cd /opt/flink ./bin/flink run ./examples/flink-java-examples-0.9.1-WordCount.jar
- This should generate a series of word counts
- Open the YARN ResourceManager UI. Notice Flink is running on YARN
- Click the ApplicationMaster link to access Flink webUI
- Use the History tab to review details of the job that ran:
- View metrics in the Task Manager tab:
Other things to try
- Apache Zeppelin now also supports Flink. You can also install it via Zeppelin Ambari service for vizualization
More details on Flink and how it is being used in the industry today available here: http://flink-forward.org/?post_type=session
Remove service
- To remove the Flink service:
- Stop the service via Ambari
- Unregister the service
export SERVICE=FLINK export PASSWORD=admin export AMBARI_HOST=localhost #detect name of cluster output=`curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' http://$AMBARI_HOST:8080/api/v1/clusters` CLUSTER=`echo $output | sed -n 's/.*"cluster_name" : "\([^\"]*\)".*/\1/p'` curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' -X DELETE http://$AMBARI_HOST:8080/api/v1/clusters/$CLUSTER/services/$SERVICE #if above errors out, run below first to fully stop the service #curl -u admin:$PASSWORD -i -H 'X-Requested-By: ambari' -X PUT -d '{"RequestInfo": {"context" :"Stop $SERVICE via REST"}, "Body": {"ServiceInfo": {"state": "INSTALLED"}}}' http://$AMBARI_HOST:8080/api/v1/clusters/$CLUSTER/services/$SERVICE
- Remove artifacts
rm -rf /opt/flink* rm /tmp/flink.tgz
