CODEWITHSUNDEEP
kubernetesactivemq-classickubernetes-statefulset
ashley
ashley

Reputation: 1038

Active MQ in HA Shared Database (Master/Slave) on Kubernetes with StatefulSet

I am in the process of deploying ActiveMQ 5.15 in HA on Kubernetes. Previously I was using a deployment and a clusterIP Service. And it was working fine. The master will boot up and the slave will wait for the lock to be acquired. If I delete the pod which is the master one, the slave picks up and becomes the master.

Now I want to try with statefulset basing myself on this thread. Deployment is done successfully and two pods were created with id0 and id1. But what I noticed is that both pods were master. They were both started. I noticed also that two PVC were created id0 and id1 in the case of Statefulset compared to deployment which had only 1 PVC. Could that be the issue since it is no more a shared storage? Can we still achieve a master/slave setup with Statefulset?

Upvotes: 1

Views: 786

Answers (1)

mozello
mozello

Reputation: 1244

I noticed also that two PVC were created id0 and id1 in the case of statefulset compared to deployment which had only 1 PVC. Could that be the issue since it is no more a shared storage?

You are right. When using k8s StatefulSets each Pod gets its own persistent storage (dedicated PVC and PV), and this persistent storage is not shared.

When a Pod gets terminated and is rescheduled on a different Node, the Kubernetes controller will ensure that the Pod is associated with the same PVC which will guarantee that the state is intact.

In your case, to achieve a master/slave setup, consider using a shared network location / filesystem for persistent storage like:

Check the complete list of PersistentVolume types currently supported by Kubernetes (implemented as plugins).

Upvotes: 1

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