The 50m ceiling on the kubernetes-* script ops is justified by a comment
enumerating what the failure path can spend, and the enumeration was
both incomplete and reassuring in the wrong direction. It listed some
collectors, said nothing about the node-join diagnostics or the
image-cache diagnosis, carried a figure for the guest Talos capture that
was half its real cost, and closed by asking the reader to keep the op
above the sum, which no ceiling can do because the sum runs past what is
left of the op on its own.
It now names the phase budget as the thing that keeps the snapshot
reachable and lists the collectors this ceiling covers, in the order the
phase spends it. It states no sums and no per-collector figures. Why the
budget is that number is derived once, beside the budget, and pointed at
from here: a figure repeated across three files is a figure that drifts,
and the drift is what the reader trusts.
It also says what the ceiling does not promise. The budget bounds when a
collector may start rather than when the phase ends; several collectors
on this path carry no wall-clock bound at all; and the bringup's own
waits already exceed this op on ceilings before a single diagnostic
runs. So no worst case is claimed, because none can be stated while that
holds.
Assisted-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>
Aleksei Sviridkin
9278702018