Only tries a build node holds count toward the 4 at once; tries waiting for a node are bounded
apart at 8, and the refusal names both counts (issue 1890: at 19:53 four tries queued behind 44
checks for up to 47 minutes refused every further try).
The checker wrote a try's asks only at its end, so a 31-minute try could not be told queued from
running (issue 1890). The try's record now names each ask as it is put, then the node that took
it, its state and the phase its step says, written on the step key's own changes. build_usage
names a running try's asks and takes a build module's capacity.<node> (configured bounded by its
node's build CPU, issue 1806's follow-up) when it is current with mesh-config.
The operator's question (how much are the build nodes used, is ace eligible) took six calls over four tools.
build_usage reads it from the bus's states: seats held (have), capacity (mesh-config resolved), pauses, the
build modules' steps by kind with left-running keys, the last hour and day with total and median time and time
at capacity, the running tries, and the backlog the view program reads from the seats' streams. A try now names
the asks it put, and the checker announces its tries readable, so the view tells a try's asks from a check's.
The waiter moved to mesh-sdk buildrun (fix/734-lost-ask, d96b9fd6), where every asker of the build seats shares it.
The builder hears DEAD_LETTERS for the go, node and image seats and asks a given-up part of a build again at once, with
the seat's words as why, instead of waiting for the check bound. The checker keeps what it does with a lost ask (a try
ends as error, a check is asked again) and its verdict words.
A check ask handed out five times during a bus reload was given up into DEAD_LETTERS and no build node wrote a step for it,
so try-1793017340003993788 stayed running for ever, held one of the four try places, and checker_try of its head kept
answering its id. The checker now hears the copies DEAD_LETTERS keeps of the build seats' given-up asks (an ordered
consumer from its start; the grant is mesh-sdk/mesh-controller DeadLetterReads, branch fix/734-lost-ask) and ends the
step it waits for: a try ends as error saying why, a check is asked again under its claim, up to three times, then fails
as not heard. A try whose ask no node takes within the step bound ends the same way (a check's backlog stays no fault,
ADR 0525 §9). checker_try_end ends a try by hand, freeing its place and stopping its judging.
The checker stopped reading a level's test results at the first that did
not pass and kept only its first failure, so a check named one fault per
round. It now reads and counts every result and writes every failed test
with its first line into the verdict's Failures and the try's failed
list (at most 50, then how many more); Failed keeps the first one's
words whole (issue 1901). Pins mesh-sdk fix/1921-every-failure.
builder_stuck, checker_kept, checker_verdicts, checker_status, checker_previews, checker_pull and checker_try listed a
bucket of thousands of keys and read each value (builder_stuck also its history) one round trip at a time before
filtering, so they timed out at 30 s. Now keys are narrowed by what the key carries first, history is read only for rows
kept, values are read sixteen at a time, at most 1000 a call with the answer saying it was cut, steps newest first, a new
try reads only the newest 64 tries, and each tool logs the values read and the time taken. Same kind as the view's fix
(PR 52); the helper is copied, not put in mesh-sdk, as a few lines do not earn a group delivery.
mesh-controller's try asked build-agent, which leaves the checking at R4e. A try is now a key in the checker's state
tries: the checker judges the head merged onto its trunk as it judges a pull request's head, through the same
judge, places and holds, writes its end in the key and owes the forge nothing (no status, no preview, no verdict).
One try per head, at most four at once; hq and a repository whose trunk the gate does not name are refused with
"no level of <repo> is checked by the checker".
jschoubben