NATS subjects

All traffic for a LabJack source lives under one prefix built from its identity:

<root>.<site_id>.<box_id>.<source_id>.<purpose>...

The root is avenars. Every token is lowercased, spaces, . and / are turned into -, and anything other than letters, digits, - and _ is dropped, so a name can never add a level to the subject or introduce a wildcard. For site i69, box i69-mu1 and LabJack i69-lj2:

Channel numbers are zero-padded to two digits: channel 3 is ch03.

Live subjects are plain NATS subjects, forwarded to central NATS over the leaf connection, so anyone with access can subscribe centrally:

nats --server nats://nats1.oats:4222 --creds apt.creds \
  sub 'avenars.i69.i69-mu1.i69-lj2.live.>'

Configuration keys

Configuration is not published on a subject you subscribe to. It lives in the key-value bucket avenabox under <site_id>.<box_id>.<source_id>.config. Use nats kv get and nats kv put rather than the bucket’s internal $KV.… subjects.

Missing identity fields

If a configuration has a structured root but lacks a field, the tokens fall back to unknown-site and unknown-box. The source token falls back to the LabJack name and then to asset<NNN>, the same way for live channel subjects, the stream wildcard, the export subject and the configuration key. An empty string counts as missing. unknown-source is used only when there is no asset number either. Setting site_id, box_id and source_id explicitly is still the clearest choice.

Legacy subjects

Configurations from before the structured layout, with a root other than avenars and no identity fields, publish on <root>.<asset>.data.<chNN>, for example avenabox.1456.data.ch11, with the asset number padded to three digits. They are still read correctly. New configurations should use the structured layout; it identifies the box without a separate lookup, and asset numbers are not unique across boxes.

Why one prefix per source

Putting site, box and source in the subject lets NATS permissions and subscriptions work at any level: avenars.i69.> is a whole site, avenars.i69.i69-mu1.> one box. It also lets central NATS route an export request to exactly one edge node without any lookup, because only that node’s exporter subscribes to its request subject.