[stsffap]

Restate is built as a sharded replicated state machine similar to how TiKV (https://tikv.org/), Kudu (https://kudu.apache.org/kudu.pdf) or CockroachDB (https://github.com/cockroachdb/cockroach) are designed. Instead of relying on a specific consensus implementation, we have decided to encapsulate this part into a virtual log (inspired by Delos https://www.usenix.org/system/files/osdi20-balakrishnan.pdf) since it makes it possible to tune the system more easily for different deployment scenarios (on-prem, cloud, cost-effective blob storage). Moreover, it allows for some other cool things like seamlessly moving from one log implementation to another. Apart from that the whole system design has been influenced by ideas from stream processing systems such as Apache Flink (https://flink.apache.org/), log storage systems such as LogDevice (https://logdevice.io/) and others.

We plan to publish a more detailed follow-up blog post where we explain why we developed a new stateful system, how we implemented it, and what the benefits are. Stay tuned!