Spring Tips: Circuit Breakers

Speaker: Josh Long
/ starbuxman
Hi Spring fans! In this tip, we'll quickly look at the Netflix Hystrix circuit breaker in Spring Cloud and the circuit breaker in Spring Retry

[@LennarthAnaya]

thank you so much. I was thinking it's a simple try/catch but I'm really glad what it is in the end

[@yaghiyahbrenner8902]

great video, the mention of spring-boot-starter-actuator was of great help. without it no stream is active. thank you.

[@shivrajjadhav7146]

Hystrix is predominantly meant for applications built using spring cloud. Having said that there could be multiple services layer for an application. e.g. Amazon (Amazon site must be having multiple services like login, products, carts, orders, payment and so on) Client (say web user) -> web application X -> Service A (it uses Data Source A ) -> Service B (Data Source B) -> Service C (Data Source C) -> Service D (Data Source D) -> Service E (Data Source E) with this kind of scenario when something breaks in Service E, How that gets navigated back to client? How Hystrix can be useful here to know unavailability of one specific functionality in Service E? If that example is wrong, then is Hystrix scope limited to multiple processes inside one service and not multiple services used in one application? Having said that above example can be tweaked something like below Client (say web user) -> web application X -> Service A -> inside Service A Lets say there are processes like process 1 ->process 2 ->process 3 ->process 4->process 5 and anything fails in process 5 gets navigated back to process 1 and then back to client. My question is more about maintaining thread state here. With try-catch thread scope is limited per service (please correct me if wrong). How Hystrix maintains state of thread during this whole transaction?

[@havenlin5633]

it is really helpful

[@psinghiitr]

Does it makes sense to use hystrix in server side? I think it makes sense to use it in client library to make server's clients more resilient.

[@dekay23]

It is useful for the server if the server does a call to any other service or api that could go down

[@ddevil63]

The nice thing about @Hystrix command is you can return Observables and fallbacks are still triggered on error. Does Retry have plans to support Flux/Mono or Observable/Single?

[@davidsyer]

ddevil actually, I don't think that feature works very well with @HystrixCommand. There is an open issue in spring-retry to support non-blocking patterns (probably version 2.0).

[@ddevil63]

Do you instead wrap the call to the annotated method in an Observable? We've been using raw HystrixCommand and HystrixObservableCommand and I'd like to make the switch to Javanica because what we're doing now is so verbose. My biggest disappointment so far is that you're forced to use Observable because Javanica doesn't seem to support Single.

[@fabiozoroa]

Nice video. The audio has a noise.