Integrate backoff retry with Vert.x Circuit Breaker

[sczyh30]

This is a good chance to introduce how and where to use Vert.x Circuit Breaker.

[pmlopes]

That could be interesting but if i'm not mistaken circuit breaker should be the main focus of other blueprint... i think if you're complete with the other one you could improve here

[sczyh30]

Yeah, Vert.x Circuit Breaker is the main focus of microservice blueprint.

At present I've implemented a basic retry backoff mechanism (with two strategies) and i think i could improve this with circuit breaker soon :-)