Ask HN: Are Service Meshes an Antipattern?

4 points by aashishkoirala 6 years ago | 5 comments

Service mesh solutions like Istio and Linkerd are gaining a lot of traction in the industry. However, it seems to me like they are predicated on what I always though was a microservices antipattern i.e. a synchronous chain of microservices calling each other (as opposed to the prescribed "right way" i.e. all inter-service communication is asynchronous through some sort of messaging). I am hesitant to outright dismiss them looking at the hype and adoption. What am I missing here, are they just helping people make their mistakes more easily?

williamallthing 6 years ago |

Because every system that needs to return a response within N ms (which is pretty much every app, service, API call, etc) ends up being implemented with synchronous calls, with messaging only used for truly offline bits. There's a good writeup of why here: https://programmingisterrible.com/post/162346490883/how-do-y... , with this great quote: "In practice, a message broker is a service that transforms network errors and machine failures into filled disks".

(I used to work at Twitter, which went through this same transformation, but if you watch tech talks from pretty much any other modern company that it building a big distributed system, you'll see the same pattern.)

aashishkoirala 6 years ago | |

Are we then paying the price in latency and added hops for development agility? I would have guessed a user request would never be subjected to that. With a mesh, don't you get even more latency because of the sidecar? The link you provided looks interesting; will give it a read, thanks!

williamallthing 6 years ago | | |

Yes, you pay a latency and resource cost to have the service mesh features decoupled from the application code. Same with any abstraction e.g. containers or Kubernetes.

You could alternatively get service mesh features in the application layer with libraries like Finagle, Hysterix, etc, and not pay that cost. But then you're tied to particular languages, and changing platform features requires making code changes.

It's a tradeoff. I talked about this at Kubecon earlier this year: https://www.youtube.com/watch?v=Z3nfLI3z0hc#t=4m58

streetcat1 6 years ago |

Most of the ideas of the service mesh came from Netflix. You should watch the orignal netflix lectures.

You are confusing the enterprise service bus architecture and micro service architecture.

Async architecture is not always the right answer. If you need it, than the recommended architecture is to use a center event log (i.e. kafka) and feed all the services from it.