Operational support is more interesting with this kind of an architecture. Dealing with message queues and all that can be challenging for a traditional organization.
Ask HN: Has anyone fully embraced an event-driven architecture?
31–40 of 173 posts
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#32Not for a company, but I've embraced it pretty hard for my home automation. It's sort of the hammer I hit everything hard enough with until it looks like a nail by making everything go through the MQTT broker. The website? A static json blob describes interesting MQTT topics, and opens a MQTT over websocket connection to read/write any state. Zigbee, et al.? Translate to MQTT. Reporting? Daemon that listens to all topics and dumps it in a Sqlite database to be queried at my leisure. Events like sprinklers on/off? Python scripts in cron jobs that talk to everything via MQTT.
Basically everything that makes fully event driven architectures difficult is ameliroated because the only consumers are myself and my wife, and we literally built up the whole system. Something appears to be locked up? There's a system of watchdogs to kill stuff, all hardware has been designed to fail off into manual control, and we can pick the pieces up at our leisure like when anything else in the house breaks. The last will and testament messages in MQTT are really nice for at least reporting hard failure conditions.
I'll be the first to admit that I would not look forward to productizing it and supporting someone else's house (to the point that I'll probably never do that). It's so easy for messages to make their way into the bit bucket when setting up a new subsystem, and everything is so loosely coupled because of the event system it's almost like it's all "stringly typed". And being both software engineers, we sort of relish in how awful the UI is, even using 98.css.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#33I had experience with a product using an event based architecture at large scale, and to be honest, it was a pain to work with. For example, traceability, or troubleshooting in general, was very hard since events would spawn more events etc. making things much harder to track than expected.
Unless the scale is an issue, nowadays I always prefer a more state-full approach when possible.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#34You mean Erlang?
erlang is great (and has events) but it is not an "event-driven" system. It is very easy to write an "event-driven" system in erlang, though. (I have done CQRS, from 'scratch' in elixir + psql, which I believe is a flavor of event-driven system). Was very straightforward.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#35Not for a company, but I've embraced it pretty hard for my home automation. It's sort of the hammer I hit everything hard enough with until it looks like a nail by making everything go through the MQTT broker. The website? A static json blob describes interesting MQTT topics, and opens a MQTT over websocket connection to read/write any state. Zigbee, et al.? Translate to MQTT. Reporting? Daemon that listens to all to…
Would you mind describing the parts that became automated? I can think of a number of appliances that could potentially be api-driven but haven’t researched them yet....
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#36My most recent (embedded) programs are almost-entirely interrupt driven, with a main loop containing only a wait-for-interrupt. So, all actions are driven by a GPIO event, RTC or timer wakeup, USB request etc.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#37them kids and their microservices...
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#38Not for a company, but I've embraced it pretty hard for my home automation. It's sort of the hammer I hit everything hard enough with until it looks like a nail by making everything go through the MQTT broker. The website? A static json blob describes interesting MQTT topics, and opens a MQTT over websocket connection to read/write any state. Zigbee, et al.? Translate to MQTT. Reporting? Daemon that listens to all to…
Would you mind describing the parts that became automated? I can think of a number of appliances that could potentially be api-driven but haven’t researched them yet....
Sprinkler system, water pressure and leak reporting, lights, mains reporting that the meter happens to broadcast, host of sensors for the house plants. Right now working on a control plane for AVB (audio video bridge) devices to give myself a sonos++ that includes video too without using sonos (I'm still salty about their "recycle mode" BS).
After that either: A) hooking up some cameras to the AVB matrix to give myself a Ring replacement too, or B) hooking all the phone lines in my old house to the AVB bridge and creating a kitsch intercom system with an old phone chosen to match each room.
After that, maybe voice assistant, but that seems like a lot. Or maybe hooking a bunch of bluetooth MCUs together on a low latency network to make the house look like a giant bluetooth device so I don't lose my audio when I go outside to do yard work.
The end goal is all the smart home stuff but I don't have to choose between Daddy Bezos and Daddy Jinping.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#39By and large, all of industry and academia working on modern robotics systems have converged on using event-driven publish/subscribe message busses for basically everything. For example, a camera driver will produce a stream of "image" events that the trigger other code across the system, all the way until a stream of "motor command" events come out the other side. This model is really valuable because it works so well with logging and replay workflows, and because it makes mocking and replacing different parts of the system really easy (up to and including mocking reality with a simulator). ROS is the major open source framework used in academia, and industry is split between using ROS and building proprietary internal protocols with similar functionalities.
It's not an exact match for the scalable-microservices world you're thinking of (for example, typically robots don't need to deal with runtime schema version skew), but could be interesting to learn about anyway.
Re: Ask HN: Has anyone fully embraced an event-driven architecture?
#40Well, every game company :)
Makes sense robotics would do it too. AAA games and robotics are basically the same field after all