Definition
Plain language
A control rule that ramps up gently and cuts back hard when it spots trouble — the same idea that paces internet traffic.
As stated in the literature
Additive Increase Multiplicative Decrease, a feedback control discipline that grows a limit linearly under healthy conditions and slashes it multiplicatively under stress.
Why it matters: AIMD is a remarkably robust way to share a contested resource fairly without central coordination, which is why it shows up far beyond networking.
For example, a TCP connection slowly raises its send rate until a packet is dropped, then immediately halves it.
Heard on the show
“The second piece of the middle layer is the one that controls how much new work gets admitted at all, and it uses AIMD.”Episode 016 — Why Your Coding Agent Stalls While the GPU Runs Hot