feature request: support autoscaling ClickHouse cluster

[prashant-shahi]

It would be really useful to support autoscaling clickhouse cluster based on some events or metrics similar to how KEDA does.

[Slach]

do you mean vertical auto scaling or horizontal autoscaling?

[prashant-shahi]

do you mean vertical auto scaling or horizontal autoscaling?

@Slach For now, what I had in mind was the horizontal autoscaling.

[Slach]

horizontal autoscaling during adding more shards have no sense, cause ClickHouse itself doesn't support data re-sharding

horizontal autoscaling for adding new replica in exists shard, have non-clean criteria for autoscaling

currently we think about autoscaling PVC size for disk, but it has restrictions, no more 1 resize in 6 hour for AWS, for example

[jirislav]

ClickHouse Cloud supports vertical autoscaling, maybe the operator could also support it?

However, it might be quite challenging as the enormous workload size often requires the nodes in k8s to be dedicated and their provisioning might require very complex integration with Openstack or AWS Node Groups.

[tomershafir]

I wonder whats the status here