The guarantee is the same and the mechanism is simpler — a nak with a
delay, no parked list, nothing lost when the controller restarts. It costs
one thing: a naked message comes back whatever happened meanwhile, so an
older report is redelivered after a newer was applied. A report already
carries the digest of the declaration it answers, so supersession becomes a
check rather than memory — ordering settled by what a message says, not by
when it arrived.
Two things. A paragraph from the superseded 0117 survived beside the 0119
correction that reversed it, so §5 said both that the amqp interface
retires and that it does not. The stale one is gone.
And the framing. §1 opened with "the bus carries five kinds of traffic
today, and this design keeps the five", with a column mapping each to the
queue it used to be — which describes the mesh's nervous system as a port
of something that did a fraction of this. It now says what the bus is: a
role addressable without knowing its holder, the mesh's own state, work
that queues until somebody can do it, and permissions derived from what a
module declared. Conditions, observation and a person's client land there
too as they are built.
Glossary gains `bus` and `the deprecated broker`, with a note on why not to
say "compatibility broker" or name it after a protocol — the second invites
exactly the backwards framing this commit removes.
0117 went a step further than it had grounds for. It was right that the bus
is the only bus, and wrong that the amqp interface must therefore retire —
because it conflated two reasons to want a broker. Using one to reach
another module is a second bus and stays refused. Needing an AMQP broker as
a backing service, the way something needs a database, is ordinary, and
forbidding it would make the mesh unable to run normal software while
calling that architecture.
So the broker becomes a plain provider module: no seat, not foundation,
never raised at genesis, no retirement condition. lavinmq now claims nothing
and provides amqp; nats claims mesh-broker and provides nothing.
The rule that survives is about direction, not software: inter-module
communication goes over the bus. A module may hold a broker for itself; it
may not use one as a channel to another module. That is a review judgement
where 0117 could have used a parser, which is the honest cost.
0106's progressive insight was itself wrong and is corrected by a second one
there — nothing moves off the old broker, so its "one purpose" sentence does
not become true, it is just not what that server is.
The insight check needed two fixes it found itself: a date may carry
trailing words, and a bold run with a link is discussing an insight rather
than marking one. All four bad shapes still fire.
29 put a module's events and tools in one namespace, 25 kept mesh.events.*
and mesh.tools.*. One namespace is right — a module's authority over its own
name becomes a single pattern the server enforces — but it needs a kind
token, because a stream is a subject filter and mesh.mod.*.> would persist
every tool call in the mesh. Tools stay on core NATS for the reason 25
already gives.
So: mesh.mod.<module>.event.<name>, .tool.<name>, and seats the same shape.
Found composing the first real configuration. Scoping every inbox to its
owner is right and leaves a responder unable to reply, because the answer
goes to the caller's inbox. The fix is not a wider grant but the server's
own allow_responses: one reply to the subject of a message the user actually
received. Without it every tool call times out while the permission list
looks correct.
Issue 115 is resolved and converted four modules away from named volumes;
the bus's own data is not the place to bring one back. Also: NATS carries
TLS on the client port rather than beside a plaintext one, so there is no
5671/5672 pair to mirror.
A module does declare requirements the provisioner fulfils — but the broker
it gets that way is a private vhost, the analog of a database, not the
mesh's bus. Two modules of the new mesh depend on it, so the compatibility
broker was never single-purpose and its retirement would have stranded them.
NATS is the heart: one bus, a module's messaging is subjects on it scoped by
what it declares, and no module is handed a server of its own. The seat
delivers nothing; the interface retires with the broker. Also closes the
EVENTS question — one stream, on the bootstrap argument, not preference.
Designs 25 and 28 go in-progress: step 1 is starting.
The insight check caught a false positive on its own first real use — its
bold-run pattern crossed newlines and joined an unrelated `**` to the
marker. Constrained to one line, still catching all four bad shapes.
PR #133 landed a different 0115 while this branch was open. The bus record
is now 0116, with every citation in designs 19, 25, 28 and the index
following it.
Note: cycle.py and records.py both fail on main as merged, on that record —
nothing cites it, and it rests on 0112, which is still proposed. Both
pre-date this branch and are left for their own change.
A record can assert a fact that goes stale while the decision it supports
stays right. Superseding for that buries a sound record under a second one
and makes every reader work out which is live. So a correction of fact is
now made in place, marked and dated, with the old wording quoted — bounded
by three conditions and checked by records.py, which fires on an unmarked,
undated or back-dated note. Judgements still supersede.
Applied to 0115: no conformance suite exists to recapture, and the full
genesis bed cannot run until the links exist. Designs 25 and 28 follow.
Counting the surface first changed the plan twice: the genesis bed cannot run
until the links exist, so it belongs to step 4, and there is no conformance
suite to recapture — step 3 builds one against the current bus before moving
it. Both corrections are recorded in the breakdown rather than edited into
ADR 0115. Also indexes design 25, which was never listed.
The NATS change was recorded as one undivided item, which hid three gaps:
a mesh already running had no adoption path, the protocol specification did
not know its transport was being replaced, and nothing was runnable until
everything was. Dividing it is what surfaced them.
Fixes, each named where it was wrong:
- reload-on is a service field; a container only has restart-on, which
recreates. Cited precedent (registry-trust-reload) is a service resource,
not a container. Fix: nats-server's own SIGHUP reload, triggered by an
in-image entrypoint watching a directory-mounted config file (issue 103's
recreate-on-change applies to a directly-mounted file, not a directory's
contents) -- asks nothing new of the host.
- A JetStream-delivered message's Reply field is already claimed by the
consumer's own ack address, so a responder using it answers nobody. Fix:
every CONTROL message needing a reply carries its reply subject in its own
payload; the controller publishes there explicitly, never via Respond().
Enrolment is the case this design actually depends on, so it's fixed there
too, not just noted.
- The listed permissions never granted publish on a durable consumer's own
ack-reply subject -- a module could receive but never ack, so every
message redelivers forever. Fixed with a scoped grant per module's own
consumer.
- One account (a deliberate choice, kept) means inbox privacy is the
permission list or nothing. The design granted 'its reply inbox' without
scoping it, which read as any user reaching any inbox. Fixed: each user's
inbox prefix is derived from its own identity and its permissions name
only that prefix.
New open question from this revision, not closed: whether the in-image
watch-and-SIGHUP shape belongs in mesh-sdk if a second module ever needs it.
Checks pass (records.py, cycle.py, index.py).
jschoubben