cri-o/vendor/k8s.io/kubernetes/examples/storm

Storm example

Following this example, you will create a functional Apache Storm cluster using Kubernetes and Docker.

You will setup an Apache ZooKeeper service, a Storm master service (a.k.a. Nimbus server), and a set of Storm workers (a.k.a. supervisors).

For the impatient expert, jump straight to the tl;dr section.

Sources

Source is freely available at:

• Docker image - https://github.com/mattf/docker-storm
• Docker Trusted Build - https://registry.hub.docker.com/search?q=mattf/storm

Step Zero: Prerequisites

This example assumes you have a Kubernetes cluster installed and running, and that you have installed the kubectl command line tool somewhere in your path. Please see the getting started for installation instructions for your platform.

Step One: Start your ZooKeeper service

ZooKeeper is a distributed coordination service that Storm uses as a bootstrap and for state storage.

Use the examples/storm/zookeeper.json file to create a pod running the ZooKeeper service.

$ kubectl create -f examples/storm/zookeeper.json

Then, use the examples/storm/zookeeper-service.json file to create a logical service endpoint that Storm can use to access the ZooKeeper pod.

$ kubectl create -f examples/storm/zookeeper-service.json

You should make sure the ZooKeeper pod is Running and accessible before proceeding.

Check to see if ZooKeeper is running

$ kubectl get pods
NAME        READY     STATUS    RESTARTS   AGE
zookeeper   1/1       Running   0          43s

Check to see if ZooKeeper is accessible

$ kubectl get services
NAME              CLUSTER_IP       EXTERNAL_IP       PORT(S)       SELECTOR               AGE
zookeeper         10.254.139.141   <none>            2181/TCP      name=zookeeper         10m
kubernetes        10.0.0.2         <none>            443/TCP       <none>                 1d

$ echo ruok | nc 10.254.139.141 2181; echo
imok

Step Two: Start your Nimbus service

The Nimbus service is the master (or head) service for a Storm cluster. It depends on a functional ZooKeeper service.

Use the examples/storm/storm-nimbus.json file to create a pod running the Nimbus service.

$ kubectl create -f examples/storm/storm-nimbus.json

Then, use the examples/storm/storm-nimbus-service.json file to create a logical service endpoint that Storm workers can use to access the Nimbus pod.

$ kubectl create -f examples/storm/storm-nimbus-service.json

Ensure that the Nimbus service is running and functional.

Check to see if Nimbus is running and accessible

$ kubectl get services
NAME                LABELS                                    SELECTOR            IP(S)               PORT(S)
kubernetes          component=apiserver,provider=kubernetes   <none>              10.254.0.2          443
zookeeper           name=zookeeper                            name=zookeeper      10.254.139.141      2181
nimbus              name=nimbus                               name=nimbus         10.254.115.208      6627

$ sudo docker run -it -w /opt/apache-storm mattf/storm-base sh -c '/configure.sh 10.254.139.141 10.254.115.208; ./bin/storm list'
...
No topologies running.

Step Three: Start your Storm workers

The Storm workers (or supervisors) do the heavy lifting in a Storm cluster. They run your stream processing topologies and are managed by the Nimbus service.

The Storm workers need both the ZooKeeper and Nimbus services to be running.

Use the examples/storm/storm-worker-controller.json file to create a replication controller that manages the worker pods.

$ kubectl create -f examples/storm/storm-worker-controller.json

Check to see if the workers are running

One way to check on the workers is to get information from the ZooKeeper service about how many clients it has.

$  echo stat | nc 10.254.139.141 2181; echo
Zookeeper version: 3.4.6--1, built on 10/23/2014 14:18 GMT
Clients:
 /192.168.48.0:44187[0](queued=0,recved=1,sent=0)
 /192.168.45.0:39568[1](queued=0,recved=14072,sent=14072)
 /192.168.86.1:57591[1](queued=0,recved=34,sent=34)
 /192.168.8.0:50375[1](queued=0,recved=34,sent=34)

Latency min/avg/max: 0/2/2570
Received: 23199
Sent: 23198
Connections: 4
Outstanding: 0
Zxid: 0xa39
Mode: standalone
Node count: 13

There should be one client from the Nimbus service and one per worker. Ideally, you should get stat output from ZooKeeper before and after creating the replication controller.

(Pull requests welcome for alternative ways to validate the workers)

tl;dr

kubectl create -f zookeeper.json

kubectl create -f zookeeper-service.json

Make sure the ZooKeeper Pod is running (use: kubectl get pods).

kubectl create -f storm-nimbus.json

kubectl create -f storm-nimbus-service.json

Make sure the Nimbus Pod is running.

kubectl create -f storm-worker-controller.json