In the previous post, we placed the time-bound gate behind the last point where delay accumulates, and from that we earned a structural guarantee: any request that goes out is, without exception, at or below the residence-time bound.
In real-time bidding, a response that misses tmax is worth zero. No matter how sophisticated the bidder, a bid that arrives after the deadline is simply thrown away. So the number I chased was not the average but the tail latency. This post is the record of tracking down one such tail.
In the last post we told the story of moving the time-bound gate that cuts aged requests behind the last aging point. This post is about what *kind* of guarantee that gate gives.
In the previous two posts we talked about the time-bound gate that blocks requests whose residence time has grown too long. One question remains: "What is the compute cost — the overhead — of passing through that gate?"
