Kubebuilder provides tooling to help get you started quickly writing operators for Kubernetes, and builds on top of controller-runtime. I’ve been looking at how errors are handled in a couple of Kubebuilder projects recently. I’d seen a couple of GitHub issues that mentioned that controller-runtime has back-off behaviour for errors so started looking through the docs to find out more, but didn’t find anything. If I get chance, I’d like to find a suitable place to send a PR to add some details in the docs, but for now I’m collating my notes here as a reference for future me!
[Read More]Connection re-use in Golang with http.Client
Just before Christmas I was working with Eliise and Lawrence and we observed port exhaustion during load testing of a Golang application that makes HTTP requests against an API. I hoped for a quick win and had a quick scan of the code but that confirmed that the was correctly reading the Body and calling Close - time to dig a bit deeper.
After some head-scratching we noticed that the code creates a new http.Client for each request. Not only that, when it creates the http.Client it also assigns a Transport instance. This last piece is very important - the docs for Transport state: