podcast: Cup o' Go — Instrumentation and Blast Radius
Jonathan Hall and Shay Nehmad had me on Cup o’ Go for episode 167, straight after their GopherCon US recap. We spent about forty minutes on instrumentation: what an APM tool is actually measuring, and the three ways you can get telemetry out of a Go program without asking every team to rewrite their handlers. The part I enjoyed arguing about most was blast radius. Manual instrumentation is precise and tedious, and it never finishes. eBPF buys you one agent covering every language on the box, at the cost of running code in the kernel, where a bad program can take the whole host down with it. Compile-time instrumentation rewrites the syntax tree behind go build through the -toolexec hook, which keeps failures scoped to one service and works anywhere Go compiles. People love this dark magic, which I find either reassuring or alarming depending on the day. ...