Is it safe to have multiple replicas of the Nextcloud pods?

[lindhe]

I want to run Nextcloud in a highly available configuration. Part of that would be to increase replicaCount beyond 1.

Clearly the chart supports this. Unfortunately, I haven’t been able to find any official documentation that assures me that running multiple replicas of Nextcloud is supported or safe from an application point of view. ^1, 2 Importantly: if it's at all supported, perhaps the exact details of the configuration matter – I have no idea.

For example, perhaps it supports multiple replicas when using an S3 backend but not with PVC storage. Or perhaps multi-part uploads require some special configuration to avoid collisions before the resulting file has been finalized. Or something with file locking or background jobs or something else. I would love to know if there are any caveats for how to make multiple replicas work safely, or if it's always safe. 🙂

It might seem silly to ask this when the chart has a replicaCount parameter , but I've been bitten before by chart parameters introducing unsafe behavior. Knowing the application's safety guarantees is important in this context, and I've not been able to get much details regarding this for Nextcloud.

Looking forward to some input on this.

Cheers!