helm: Stateful components emptyDir inMemory option about mimir HOT 6 OPEN

the compactor can be configured to mount extra volumes via compactor.extraVolumes and compactor.extraVolumeMounts and disable the conventional storage via compactor.persistentVolume.enabled. Does this not work for you?

Worth noting that for compactors and store-gateways doing this will not result in any data loss. Merely more work to do for the compactor and longer startup time for store-gateways (but also see #8166)

However, doing this for ingesters is very likely to result in data loss. One way to work around this is to set -blocks-storage.tsdb.flush-blocks-on-shutdown, which only incurs temporary data loss until the compactor, store-gateway, and querier discover the flushed blocks. But an ungraceful shutdown of an ingester will lead to permanently losing data for the zone.

from mimir.

@dimitarvdimitrov I see no option to disable persistent storage fully. Options are PVC or emptyDir. Quote from chart values:

  persistentVolume:
    # If true compactor will create/use a Persistent Volume Claim
    # If false, use emptyDir
    #
    enabled: true

from mimir.

you can still mount a memory-based volume and configure the compactor to use it as a working volume: set mimir.structuredConfig.compactor.data_dir to the directory of the mount from compactor.extraVolumeMounts. The emptyDir will be mounted by unused.

from mimir.

Can you provide an example how to mount a memory-based volume? I could not find any info about such type of k8s volumes. And I suspect that additional rights may be needed, is it really possible in rootless environment?
Nevertheless I guess some additional rows in helm templates and values would be more usable solution.

from mimir.

these are the helm values I was thinking of. Haven't ran it in a bigger cluster, but seems to work ok in k3d.

compactor:
    extraVolumes:
        - emptyDir:
              medium: Memory
          name: in-memory-data
    extraVolumeMounts:
        - mountPath: /volatile-data
          name: in-memory-data
mimir:
    structuredConfig:
        compactor:
            data_dir: /volatile-data

from mimir.

running ingesters with in-memory PVC is dangerous, so I don't think the chart should support this natively. Doing this for store-gateways and compactors see like less of an issue; I'm not opposed to it

from mimir.