When writing a new Spring web app, teams often have some nagging scaling doubts: - How many users can my app simultaneously handle? - How fast will my @RestControllers dash out those JSON responses? - How much memory, CPU, or I/O does my application need? - How much money do I need to spend on hosting? Surprisingly, there's very little advice out there on how to sensibly approach these questions in a practical way—apart from simply autoscaling random Kubernetes pods into oblivion. In this #almostnoslides session, we're going to use an IDE, a pen tablet, and a few libraries to get a deep, practical understanding of the following: - Throughput and latency: How to (reliably) find out how many users your Spring app can handle - CPU/memory/IO: How much (or how little) your app actually needs - Hosting: What server your app needs By the end of this talk, you'll have learned solid load-testing processes and skills that make you never worry about scaling your Spring web apps again. Speaker: Marco Behler, Developer Advocate, JetBrains

1. Why you don’t need to worry
about scaling your Spring web
app
Twitter: @MarcoBehler - YouTube: MarcoCodes

2. Thoughts
● Absolute Numbers vs Real User Journeys (StackOverflow)
● Whole Infrastructure Tests (Weakest Link, Distributed Flamegraphs)
● Expectation Management (Normal Life vs Black Friday vs PS5)

3. Further Reading
● Code: https://github.com/marcobehler/high-performance-java
● Jetty-Perf: https://github.com/jetty-project/jetty-perf.git
● Krzysztof Ślusarski:
https://krzysztofslusarski.github.io/2022/12/12/async-manual.html
● @MarcoBehler Twitter / YouTube / www.marcobehler.com

4. Thank you!