jschoubben
53b94c51bb
Three records were left describing a mechanism a new record had moved, and a reader arrives at them by following a citation: 0066 still said a routed name is written into every container after 0148 replaced that with resolution; 0016 still read as though the lab were the test bed after 0149; and issues 109 and 135 said nothing about 0148 ending the copying that 135's own fix made comparable. Each was a citation leading to the wrong answer in a record that was not wrong about anything it decided. This is the second time in one session. The playbook rule I added last round did not stop it, so the convention is now written where the record conventions live, with the shape to use and three worked examples — and with the honest note that it is NOT machine-checked and cannot be from `extends:` alone: 102 records extend another, 87 have no back-reference, and that is correct, because extending usually means building on a context. Making it mechanical means a record declaring the relationship in frontmatter, which is a schema change and is not mine to decide. Also: designs 18 and 20 claimed `updated:` dates from before I edited them, and 117's `fixed-by` gained the commit beside the record.
5.0 KiB
status, opened, located-in, fixed-by, amended-design
| status | opened | located-in | fixed-by | amended-design | |
|---|---|---|---|---|---|
| resolved | 2026-09-28 |
|
mesh-host — a container's mesh names are part of the spec digest the host compares, sorted so the digest does not move for a reordering. A container whose names moved is now recreated like a container whose image moved, and the test fails against the previous behaviour. |
135 — A container's mesh names are not compared, so a moved address is never noticed
What was observed
One container on this mesh had been restarting every thirty seconds for five days — 2286 times — and the mesh reported the machine as doing what it was told.
Its logs said its database connected and then a query timed out. The database was reachable: the same
query from the same network, with the same credential, answered in milliseconds. What differed was the
name. Inside that container, novox.internal resolved to 10.42.0.1; in every other container on the
machine it resolved to 10.10.0.1. The mesh's overlay range had moved, and this container still held
the old one:
umami created 2026-09-23 novox.internal:10.42.0.1
mesh-catalog created today novox.internal:10.10.0.1
A container resolves other machines and public names through the entries the mesh gives it when it is created, and nothing re-reads them afterwards. The host compares a container against what was declared by a digest of its spec — image, name, environment, ports, volumes, arguments, resolver, address, and what it reads — and the mesh's names were not in it. So this container matched what was declared, was left alone, and kept an address that had not existed for five days.
Forty-eight other containers had current names. Not because anything corrected them: each had been recreated for some other reason — a new image, a changed file — and picked up the current roster on the way. This one's image is an upstream release that had not moved, and nothing else about it changed, so nothing ever recreated it.
Why it matters beyond this instance
It is the exact fault issue 045 named, in the one field that was left out. That issue is why the digest carries what a container reads: "a container whose configuration had since been rewritten compared equal and was left alone — running values the machine no longer holds, while every check reported success." The same sentence describes this, with names in place of files.
The failure is invisible in exactly the way that matters. The container runs, so the machine reports it applied. It restarts, but a restarting container is a normal sight during an upgrade. The only account of the fault is inside the container's own log, in the words of the application rather than of the mesh — and what it says is that a query timed out, which points at the database.
And it is most likely to bite what changes least. Every container that is rebuilt often repairs itself by accident. The victim is the module whose image is stable — which is to say, the module that was working fine.
What was done
The mesh's names are part of the digest, sorted so the digest does not move for a reordering nobody made. A container whose names moved is now recreated exactly as one whose image moved.
The first apply after this recreates every container that carries mesh names — one restart each, already the price the mesh pays for any image update — because their recorded digests predate the field.
What is still true
The mesh gives a container its names at creation and has no way to change them in place. That is the container runtime's shape, not a choice; the answer is to recreate, which is what this does. A module that would rather re-read a roster from a file can already ask for one as a fact (ADR 0120) and restart on it.
What replaced this fix (2026-09-30)
The fix here — putting the mesh's names into the digest the host compares, so a container whose names moved is recreated like one whose image moved — worked, and cost more than it was worth. It made the roster part of every container's identity, so one name moving replaced every container in the mesh: a module assigned on one machine restarted the store, the registry, the edge and mail on another (issue 151).
ADR 0148 goes at the cause this record only described: a copy taken at creation is stale the moment the roster moves, and detecting that is not as good as not copying. A container resolves the mesh's names through its machine's resolver, at the moment it asks, so the fault this record reports cannot occur rather than being noticed a restart later.
Recorded here because this is where somebody arrives to find out why the digest carries names, and the answer is that it did, for two days short of a month, and stopped.