scale stateful set with shared volume per az

Question

I would like to scale a kubernetes stateful set in EKS which serves static data. The data should be shared where possible, which means by availability zone.

Can I specify a volume claim template to make this possible? Or is there another mechanism?

I also need to initialize the volume (in an init-container) when the first node joins. Do I need to provide some external locking mechanism rather than just checking if volume is empty?

score 0 · Answer 1 · answered Dec 13 '21 at 08:34

0

If you want your pods to share static data, then you can:

Put the data into the Persistent Volume
Mount the same volume into the Pods (with ReadOnlyMany)

A few comments:

Here you can find the list of volumes, so you can choose the one that fits your needs
Since every pod serves the same data, you may use Deployment instead of StatefulSet, StatefulSets are when each of your pod is different
If you need the first pod to initialize the data, then you can either use initContainer (then use ReadWriteMany instead of ReadOnlyMany). Depending on what you try to do exactly, but maybe you can first initialize the data and then start your Deployment (and Pods), then you'd not need to lock anything

answered Dec 13 '21 at 08:34

Rafał Leszko

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So I'd create the volumes separately, rather than having them created as the first pod in an AZ is created? – shaunc Dec 13 '21 at 13:59
yes, you can do it this way. – Rafał Leszko Dec 13 '21 at 14:55
ok ... but how about if I want to create and remove volumes as first/last pod in AZ is removed? – shaunc Dec 13 '21 at 15:25

scale stateful set with shared volume per az

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