I just faced a whopping $3,200 bill due to a misconfigured AWS Lambda function that got stuck in a loop, triggering itself over and over whenever an S3 write happened. I had no idea until I checked the billing dashboard days later, and it was a huge shock. AWS support did manage to forgive part of the bill, but I've been left wondering how to avoid such issues in the future. Does anyone know of tools or practices to catch usage anomalies in real-time, rather than just relying on monthly budget alerts? What safeguards could have prevented this disaster?
5 Answers
Setting an alarm with a kill switch could be a smart move. You can trigger another function to cut off permissions if funding goes over a specific threshold, which sounds like a solid safety measure.
Don’t forget about the recursion guardrails that AWS has in place for Lambdas. By default, it stops after 16 recursive invocations. Setting up reserved concurrency can also cap the number of concurrent executions, which is a good safety net. Plus, keep an eye on your execution metrics after deployment to catch any weird spikes.
Those metrics are crucial! It’s part of responsible Lambda management.
I had a similar experience back in 2018 when I ran up a $10k bill. AWS was pretty lenient and forgave it, but now I always set up billing alerts, just as a precaution. It can happen to anyone!
You should definitely set up billing alerts right when you create your AWS account. They can at least notify you before things get completely out of hand. Also, there are some advanced tools like cost anomaly monitors that can help with real-time monitoring of usage spikes, which is super helpful.
Totally agree! Those anomaly monitors are a lifesaver. I wish AWS made these alerts easier to set up for new users.
Right? It feels like something so critical should be highlighted during account creation!
It’s important to confirm how recursion is being managed. If your Lambda’s triggering method is misconfigured, it could overlook the recursive limits. AWS has docs about how to handle recursion properly, so make sure to check those as well for better practices in the future!
Definitely! Keeping an eye on documentation can save a lot of headaches.
Exactly, I always refer back to the docs whenever I’m unsure about any function setup.
That's good to know! I thought the guardrails were just a suggestion. I'll definitely set concurrency limits next time.