Service Fabric Mesh, unlike Service Fabric, is more similar to a container orchestrator like Kubernetes. And it does not support ReliableCollections
. Instead, it supports Volumes as mentioned in the docs, with the option for Service Fabric Reliable Volumes or Azure File Share Volumes.
Considering your use case, Redis would be the best external distributed store for you to leverage as a in-memory data structure store. But you should be able to use any data store depending on your exact requirements.
Also, you could consider using dapr, a distributed application runtime, which shares many aspects with service fabric while being language agnostic.