Cloud Deployment :: Distributed Cache/Storage

Docker volumes are almost as worthless as bind mounts at multi-node swarm cluster; neither survive container lifecycle; new container of a service may spawn at other node (engine) and so may not have the same docker volume.
REX-Ray volume plugin installs per vendor-specific driver; tested @ AWS (EBS), and supposedly works at DO too, but that's about all.
Redis, as a single instance, is for ephemeral cache; does not survive container lifecycle. That is, no viable persistent storage under a multi-node swarm. (See Docker volumes issue, above.)
Redis HA per Sentinel is a (candidate for) swarm-wide solution to cache and storage.
- This involves a minimum of master, slave and sentinel. Clients connect only to sentinel, which selects an apropos (functioning) master/slave.
- Requires data initialization from the Source of Truth.
MinIO is an S3-backed server (and adding new storage vendors), but no longer supports Docker Swarm; only the hellscape of Kubernetes.

Read-only solutions