[Replication] Implement replication namespaces

[JonathanMace]

The ideal way of implementing service replication within Blueprint's compiler is using namespaces, rather than explicitly instantiating service instances. Ultimately, for horizontal auto-scaling, namespaces will be the only way of implementing this within Blueprint's compiler.

We want to add this kind of replication, and probably also make use of it with Kubernetes auto-scaling.

[alessandrocornacchia]

Thanks for your dedication to this project, it's really cool! Is replication / horizontal-autoscaling something currently implemented? The Blueprint paper seems to refer (for UC2) to an experiment with replication. However while playing with the sample applications, I don't find an obvious way/plugin to handle container replication and load balancing across container replicas.

Thanks!

[vaastav]

Hey @alessandrocornacchia, the replication we refer to in the paper is about mongodb replication where there is a primary and a replica for the database. I don't think we have ported that option for the mongodb plugin yet from the previous version of Blueprint.

Currently Blueprint doesn't have a plugin implemented for load balancing or container replication. We are in the process of implementing them via the Kubernetes plugin which could support horizontal scaling + load balancing. We also have a WIP branch for a dedicated replication + load-balancing plugin that is not tied to a specific deployment framework.