Supporting Disconnected Operation of Stateful Services Using an Envoy Enabled Dynamic Microservices Approach

Dynamic microservice and service mesh approaches provide many benefits and flexibility for deploying services and setting policies for access control, throttling, load balancing, retry, circuit breaker or shadow mirror configurations. This paper examines extending this to support continuous operation of stateful microservices in hybrid cloud / edge deployment, without loss of data, by permitting disconnected operation and resynchronisation. These are important considerations for critical applications which must continue to operate even during prolonged cloud disconnection and node or client failure. Such service requirements are typical of retail and other scenarios in which services must run continuously, while maintaining a consistent state between cloud and edge service instances. The approach taken and evaluated in this paper exploits a lightweight Envoy proxy within Choreo connect microgateways and Consul service mesh sidecars. Envoy proxies are able to efficiently perform shadow mirroring of requests and support graceful failover, but requires additional functionality to support resynchronisation and recovery from failure that are examined in this paper.