Stateful Serverless Applications - Guillermo Rauch @ PrismaDay 2019

[Music] so I have a lot to talk about today because this server list thing is really really big and it's also really really new and a lot of people mean different things when they double it serverless so we're gonna have a great time today so the talk is therefore divided into three parts and I'm introducing an innovation I'm a color coding this presentation each part gets a color so there's yellow

pink and green so part one is going to be very congruent to the point what the heck is serve less again and I mean again because there's been several in several attempts to define it and I feel like the industry as a whole is kind of not agreeing about what they mean when they talk about server less so part two is about how state actually works in

serverless because the title the presentations is sustainable and you can already anticipate that someone's gonna be like no but several is stateless yeah you're right and you're also not right so we're gonna talk about that later in part three is how to make this whole thing work so how do you use the state how do you leverage the statelessness but how do you also solve for sinfulness which is I mean a lot of applications in states and they need to be stateful so

let's start with part one and what this serverless thing is again so I referring to this universal wisdom that opinions are like butts everyone has one probably someone said this in the past I'll attributed to later Socrates and I'm gonna take that I'm gonna take you to the next level the serverless level that I think that the finishes of server lists are like butts every platform has one and that's me who by the way I

operate a platform so I have a lot to say about this so what's our definition of serverless I are the visual service is pretty uncontroversial so way back in the day a lot of you in this room used to just deploy applications by just writing a bunch of HTML files CSS files and some dynamic magic files like PHP files or Perl files yes you were doing that and

with that simple sort of heuristic we can imagine what our Minimum Viable serverless app would look like so in my opinion a the most minimum serverless app would have a static file and this is special service function or lambda file so static file is pretty uncontroversial we all know them this magic file is one that when a request comes in instead of being served

directly from the cache at the edge of a CDN for example it gets executed on the Manns it's a function I'll and the function typically called so for those of you that are familiar with the gem stack you can think of this as the am stack because there's no need for JavaScript to be inside the HTML file but we can also call it a gem stack as well so functions can be written in any programming language in this serverless

ecosystem in service world the only constraint is that they have to run to completion so when the request comes in the code runs it needs to do stuff and then it has to complete it doesn't keep running later on so that's a critical constraint and typically this release function looks like this just the most fundamental primitive that you could find in larger and larger frameworks so if you've been writing Express or things like that you always end up with something that is just a request Handler