Two controllers could both act (issue 204), a reconcile's report could
overtake the apply after it and the digest decided (issue 267), and a grant
could make a second writer of a machine's report.
- The lease (internal/lease, ADR 0229): mesh-controller_lease key `holder`,
15 s age, renewed every 5 s by compare-and-set; the epoch is the revision
it was taken at. The gate is the clock (stops 3 s before expiry); a refused
renewal is a loss and the process exits; a holder that stops gives it back.
serve takes it before asserting the bus. Epochs kept in the store
(migration 0068 controller_epoch) as a floor: a bucket raised from nothing
is compacted past it. Unleased (no epoch, S12 urgent) only when nobody
holds it and the bus will not let it be written. A shell command acts
under the holder's epoch, or its own lease when none.
- Declarations carry `epoch` inside the signed envelope, only to a machine
whose latest account carried a report_sequence (mesh-host #35); would-send
is composed with the epoch last sent. Allot and the send both pass the gate.
- Reports: contract in internal/link/order.go (epoch, sequence,
report_sequence, older_than, refused_older). Accounts kept by epoch, then
sequence, then report sequence; older refused, counted; unordered reports
keep the digest rule. Plans by compare-and-set on a revision, with epoch.
Conditions and calls carry the epoch and are not written off the lease.
- S12 and S13 (naming the writer by epoch) watched, D5 run; reset of the
bucket said. Writers table compiled in and enforced in PermissionsFor; the
controller no longer publishes mesh.control.>. A contract per consumed
kind, and the empty-on-error lint over the repository.
- mesh-host pinned to its main with the epoch in the validator (D1 validates
the envelope as sent).
Needs mesh-host's genesis lock with the lease grant (mesh-host PR) for
TestTheInstallersFirstUserListIsWhatTheControllerWouldCompose.
A named push flushed every other machine whose declaration differed from
what it was last sent (hq ADR 0083). Under an upgrade policy of `record`,
or a plan still waiting on its first machine (ADR 0218), every machine
running the module differs, so `push <one>` sent the held build to all of
them (hq issue 259).
Each send now records which build of each module it carried
(node.sent_builds, migration 0061). The cascade, and the bus holder added
to a named push, skip a machine any of whose modules would move to a
build its policy records or an open plan has not sent it, and say which
module, which build, why, and that `push <node>` sends it. A machine
whose last send was not recorded is held until it is named. The named
machine itself, a whole-mesh push and `push --behind` are unchanged.
jochen