$ cat post/the-rollback-succeeded-/-the-logs-held-no-answers-then-/-the-socket-still-waits.md
the rollback succeeded / the logs held no answers then / the socket still waits
Title: Debugging the Demons of DORA
November 18, 2024
Today marks another day in the life of a platform engineer, but this time I’m finding myself reflecting on the chaos and clarity that comes with it. The tech world is abuzz with AI/LLM infrastructure explosions, FinOps battles, and DORA metrics everywhere you turn. Let’s dive into some of the challenges we faced in our recent project—specifically, how we managed to debug a complex issue involving server-side WebAssembly and FinOps pressure.
A Tale of Two Systems
We were building a new feature for one of our flagship products using WebAssembly (Wasm) on the server side. This was all part of a broader initiative to reduce cloud costs while increasing performance. The idea was simple: move some heavy lifting from the client to the backend, leveraging Wasm’s powerful capabilities.
However, as soon as we deployed it in a staging environment, the logs started painting a grim picture: high memory usage and slow response times. This wasn’t just an inconvenience; it meant we were hitting our FinOps budgets harder than planned. Time for some serious debugging!
The Debugging Begins
The first step was to gather all relevant information from the server-side Wasm logs, which weren’t as straightforward to read compared to traditional logs. We spent a few frustrating hours parsing through these logs before realizing that we needed better visibility into what our Wasm functions were actually doing.
We integrated a custom logging solution to capture more detailed data about memory allocation and function execution times. This gave us the insight we needed to start identifying the bottlenecks. Turns out, one of our core functions was being called way too often, leading to excessive memory consumption.
The Root Cause
After isolating the problematic function, it became clear that there was an issue with how data was being passed between JavaScript and Wasm. We were inadvertently creating unnecessary copies of large objects, which ballooned our memory usage. Once we optimized this by passing references instead of copies, the memory usage dropped significantly.
But the real kicker came when we realized that we had a race condition in another part of the codebase. This was causing frequent crashes and adding to the overall load. After implementing a proper locking mechanism, things started running much more smoothly.
FinOps Frenzy
Meanwhile, our FinOps team was watching the budget metrics with bated breath. We needed to ensure that we were meeting our cost targets without compromising on performance or functionality. This meant constant communication and collaboration between DevOps and engineering teams.
We leveraged DORA (DevOps Research and Assessment) metrics to keep track of lead time, deployment frequency, and mean time to recovery. These metrics helped us identify areas for improvement in our CI/CD pipeline and incident response processes. We also introduced a new tool that allowed us to more accurately forecast resource usage, giving us better visibility into cloud spending.
The Lesson Learned
The whole experience was a baptism of fire for everyone involved. It taught us the importance of having robust logging mechanisms, proper optimization practices, and strong communication with FinOps teams. Debugging Wasm is no walk in the park, but when you have the right tools and an open mindset, it becomes manageable.
In the end, we shipped a more stable and cost-effective solution than initially planned. It’s always rewarding to see the hard work pay off, even if it means staying up late into the night debugging code and optimizing budgets.
Looking Forward
As I sit here reflecting on this journey, I’m reminded that every challenge is an opportunity for growth. The tech landscape continues to evolve at breakneck speed, but as long as we embrace these challenges and learn from them, we’ll be better engineers and platform managers tomorrow than we are today.
Stay tuned for more adventures in the world of server-side WebAssembly and FinOps!
That’s where I’ve been this month. What about you? Have you faced similar challenges or had any exciting tech moments to share?