- `service` node type: command, port, worker label, health path, env and
weights (an artifact digest the worker fetches as {weights}). Its flow
starts it; it restarts with backoff, reads degraded while starting or
without a worker and down after three starts that never got healthy, and
publishes http://<worker>:<port> once /health answers 200, "" when it ends.
- Worker protocol 3: a `serve` call, every call in its own process group,
killed when the engine ends the call, the socket drops or the agent gets
SIGTERM. `--service-host` overrides the address the engine sees.
- Services and compiles take no `--parallel` slot, and a flow's detail is
built off the event loop, so a save no longer stalls the engine.
C4: a device's `viewers` (superusers by default, or members) covers the
image and video messages its ports publish. Anyone else gets none of their
values on the socket, in the catalogue or a flow's state, 403 for their
history, for the frames they hold (the last 8 included) and for TURN
credentials, no bytes when asking for them, and `bye: forbidden` for a live
view. A device credential stays bounded by its dashboards. The device page
sets it in its Camera section, and a tile the viewer may not see says
"No access to this camera" and asks the camera for nothing.
C3:
- A volatile upload is held to MAX_FRAME_BYTES (4 MiB, 413 above it, read
without extra copies), and so is a frame on a device's socket.
- A frame the engine holds in memory is written to the ring directory
before a local worker is handed it, so load_artifact finds it.
- A socket the bus dropped events for catches up with a snapshot, demand
included, and a device's credential is checked again per frame, cached by
the flow store revision and its nonce, so a lost event never keeps an
unpaired device's frames coming.
- A report is at most 64 KB once its named config_schemas are put in place.
- A device away for 60 s has its true bool messages set to false.
- Refused frames are logged by fixed keys, a frame is named after its
message, `fluksio serve` waits 5 s for open connections, a tile with a
stream URL creates no demand, the 8-name cap keeps the newest names.
- Every container's log rotates (json-file, 3 x 10 MB).
- Volatile frames are held in memory with a byte-bounded queue instead of
the /dev/shm ring scanned on every put; workers keep writing to the
directory, which is trimmed on a timer. A volatile upload no longer spools
to disk. ARTIFACT_VOLATILE_BYTES=0 turns the ring off.
- A device sends camera frames as binary messages on its socket, held and
published in one step and credited to its device node; refused frames are
logged and dropped. Its snapshot carries demand and the uplink (binary, or
http through the portal).
- One demand registry for every socket's wanted media, the tunnel's
included, plus what running flows read, mapped onto on-demand ports and
published as device_demand; at most 8 media names per socket.
- Per-message deflate off in serve and dev; a device may fetch the last 8
digests of a message; published dashboards cached per store revision; a
revoked device socket is closed with 1008.
- Media tiles want bytes only while on screen; the Devices tab previews a
wired camera; the device node warns when a flow reads an on-demand port.
- POST /devices/pair answers a 2-character `check`, listed by /devices/pending
and shown beside each waiting entry; five codes a minute per address, and at
50 waiting the oldest gives way instead of a 429
- portal-minted device tokens are asked for with the device's nonce (`pnc`) and
held against it, so unpair and delete revoke them; one without `pnc` stands
only while the nonce is 0
- a device credential acts as the device (`device_principal`), not as the
approving superuser, so deleting that account unpairs nothing
- the report is validated port by port: unknown enum values read as `unknown`,
unreadable ports and sections are left out and logged, `config` may name an
entry of `config_schemas`; 422 only for no schema 1 or no object
- devices.json is parsed once per change (cached by stat), delete drops the
report and keeps the nonce, a busy recheck runs in the background
- scope and io only from enabled flows (start/stop tells the devices), a port
bound twice gives one io row
- the Devices tab's saves cancel and hold back device refetches until settled
- A device credential that cannot be checked now (device store not running,
nonces unreadable) raises DeviceUnavailable: 503 over HTTP, and the
/flows/ws handshake and the tunnel stream accept and close with 1013.
1008 (a 403 before accepting) stays for a revoked or invalid one
- Device files are written through a temporary file, so a read mid-save no
longer looks like a deleted device
- The first report turns Touch friendly on only for a device paired since
pairings are noted (DeviceState.paired_at), so devices paired before keep
the switch they were given
- NodeDef reads `device`/`device_policy` from older clients as the worker
label, for a release
- Tests: transient vs revoked socket, the touch default, the old worker keys,
and a restart with a device node and a node_health rule sending no push
A device reports its board, screen, camera and ports from its own
credential (16 KB, schema 1, replacing the last report), and the flows
are validated against it again. The node panel turns a reported port's
config schema into a form, a reported screen is a canvas preset and a
touch screen's first report turns Touch friendly on. An offline device
node is degraded: amber on the canvas, a warning on Home, never a fault.
- NodeDef `device`/`device_policy` become `worker`/`worker_policy`, the
issue `ignored_device` becomes `ignored_worker`, and the SDK's `@node`
takes `worker=` and `worker_policy=`
- FlowStore._migrate renames the keys in published and draft documents
once, bumping their version; a queued run's `needs` reads the old key
- placement passes the label as `label`, client regenerated
- docs: worker placement wording, MCP issuer without DOMAIN, device rows in
the CLI data directory and the API table, device links in compose comments
- flow/nodes/device.py: `device` node with params `device` and `config`;
provides the device's `in` ports, requires its `out` ports without
waking anything, never run (Node.passive), down "Offline" from presence
- DeviceDef.io and DevicePort go; GET /devices/{id} computes `io` and
`bindings` from the device nodes of published flows, in a fixed order,
cached by FlowStore.revision; the credential's scope comes from them
- issues `unknown_device` and `device_port` (wired twice; against a report
the wrong direction or dtype, or unlisted as advisory), rechecked when a
device is created or deleted; ValidationIssue.advisory is a field
- a device publishing on a bound port is credited to its node by the
server; the panel endpoint kind is gone from `_endpoints` and the canvas
- a rebuild that moves a device's bindings sends `dashboard_changed` with
an empty name, which the firmware refetches on
- startup moves each device's `io` rows into device nodes in the flows
declaring their messages, draft and published, one commit; rows no
flow declares are logged and left out
- frontend: Device node settings (device, Publishes, Follows, a port
picker from a report), palette shortcuts per reported port, DeviceDetail
lists bindings with "Use in flow" in place of the I/O editor
- docs: devices, flow editor, node types, issues, API
- flow/devices.py: DeviceDef in FLOWS_DIR/_devices/<id>.json, committed under
the flow store's write lock, 409 on a stale version; nonces in DEVICES_FILE
outside git; in-memory presence announced as device_status
- api/routes/devices.py: CRUD, pairing with an optional {name, board,
firmware}, a pending list adopted without a code from the LAN only, unpair;
/panels/pair, /panels/pair/{code} and GET /panels/{id} kept as aliases,
PUT /panels/ gone
- _device_may replaces _panel_may, JWT claims unchanged
- panels.json moves into devices once at startup, then .migrated
- MCP list_devices, get_device; search category device
- Devices tab (list, detail with presence, pairing, ordered dashboards,
touch, I/O), PanelsDialog removed, serialised optimistic saves
run_coroutine_threadsafe refused it and it was never awaited, a RuntimeWarning
under pytest 9. The cancel still logs that it could not reach the worker.
Its entries are the cards present, and a local child's allocation is
named through them, so under =2,3 card 0 is device 2. Remote workers
keep mapping against their own mask.
DELETE /flows/library/{name} still answers 409 while nodes use the source.
With detach=true each of them keeps a copy of the code, in the published
flow and the draft, the source is deleted and the running users rebuild.
mqtt and http take websocket's vocabulary: their Mode is LISTENER/SENDER,
default names read mqtt_listener_… and http_listener_…, and mqtt's
publish_queue_size is send_queue_size. No alias stays behind, so the flow
store rewrites the old setting in every published and draft mqtt node when it
opens, in the same migration as trigger → debounce. Every mqtt and http
setting carries a one-line description for the editor, and the node-types
reference uses one wording for direction and says that an http sender
publishes a JSON object response on its outputs.
A push session that failed before it listened left only a task_crashed
event. The wrapper in _run_supervised now reports down with the exception,
unless the loop already said why it is down.
The store rewrites `"type": "trigger"` to `debounce` in every published and
draft flow when it opens, bumps the version and commits once. No alias stays
behind, so `trigger` is now an unknown type.
ws:// and wss:// URLs dial out and hold a supervised connection; a path is
served under /hooks/<flow>/ with an optional secret. Outputs only listen,
inputs send. Frames are JSON keyed by port, with json_key and on_connect.
The generated batch script exported nothing and passed `--token`, which
any user on a shared compute node reads from `ps`. It now exports
FLUKSIO_WORKER_TOKEN after `prerun`, which the worker already reads.
fluksio-worker now refuses ws:// and http:// engine and artifact URLs unless
they are loopback or --insecure is given; the engine still accepts both.
An artifact reference must be sha256: plus 64 hex digits before it is joined
into a path, and node code gets the host environment through the engine's
credential denylist instead of all of it.
The session db fixture now disposes the engine before deleting the file, since a
module under a no-op db (tests/sdk, tests/flow) may have connected first; the
sdk import tests forget the study packages they import; the supervision tests
keep the real quarantine length so it cannot expire mid-assertion.
A worker over FLOW_WORKER_MAX_RSS_MB (--worker-max-rss) when its node
returns is retired instead of kept warm, in the shared pool and in every
declared one; 0, the default, keeps them all. The engine now accounts its
own memory (FLOW_RAM / --ram, else the box or the cgroup limit less 1 GB),
so a node's `ram` declaration holds locally. A declared environment the
shared pool already has is that pool rather than a duplicate set of warm
workers.
A connector that misses one poll turned the health badge amber and the node
on the canvas red until it recovered. `LoadedNode.health_since` marks when the
status last actually changed — a rotating error detail under an unchanged
status does not move it, or a connector retrying with a different errno each
poll would never debounce — and `unhealthy_nodes` applies a 60 s floor to it.
The floor is on the surfacing, not on the transition: the stored health is the
truth the moment a node reports it, so a flow reading node health is never
told a stale story. Only going down is held back; recovery clears at once.
Home's "recently modified" order was a proxy — drafts first, then the
version counter, then the name. Both summaries now carry `updated_at`,
read as the mtime of the working copy: every write in the store commits
immediately, so a file's mtime is its commit time, and `git log -1 --
<path>` costs ~990ms across this instance's 15 documents (it walks the
history back to the last commit touching each one, so it is slowest for
the stalest) against ~1.8ms for the stats. No cache needed.
`DashboardSummary` also carries `footprint`: each widget as its type plus
the placement a panel resolves, which is the whole of what the mosaic
draws. That drops the document fetch per tile and with it the cap of
eight, past which tiles showed a name and nothing else. Verified against
this instance's 8 dashboards: the blocks are identical to what the old
client-side derivation produced.
A python node's ports and settings arrive as keyword arguments, so a declared
name its `process` does not take was a TypeError on every call — and a node
that loads fine and fails every time it runs is the quiet kind of broken: the
hosted demo did it 720 times an hour for two days and the health badge read
ok throughout. `_build_node` now reads a written body with `ast` and refuses
the mismatch at load, so the node is an error on the canvas and an issue on
publish. Skipped for `**kwargs`, a decorated or absent `process`, and the
template a new node opens with. The SDK's generated shim always takes
`**settings`, so synced flows are untouched.
`/observability/summary` names a node that has failed in the last fifteen
minutes and reads degraded while it does, which is what would have made the
badge amber. `nodes.failing` carries the count.
Each was a loose end recorded under `### SDK` in the notepad.
`serve` takes its own pidfile down on SIGTERM. uvicorn restores the handler it
found and re-raises the signal it stopped on, so the default handler ended the
process without unwinding and the `finally` never ran — which is what a stop
sends, and what left `serve.pid` behind.
`serve.log` is cut back past 5 MB by the engine rather than by the screen that
started it, so an adopted engine is bounded too. Gated on its own stdout being
an appended regular file, which is what makes the cut safe: the kernel then
puts the next write at the new end.
Cards are counted from `/dev/nvidia[0-9]*`, so `FLOW_GPUS`/`--gpus` of 0 means
"work it out" the way `FLOW_CPUS` always has. The engine counts, not the
accountant — a remote worker builds one of those from its own inventory, and
detecting there would hand it the engine host's cards. The worker counts last:
what a batch job says it was granted still wins.
`GET /runs/metrics/names` is the distinct over a selection that `--list` and
the terminal's metric picker were approximating by reading the newest run that
had measured anything, which missed a name only an older run ever wrote.
`MetricSink` announces each batch it has written (`run_metric`, carrying the
names). Not a per-point event: one covers up to 500 points or two seconds of
them, and the rows stay the record. The terminal comparison fills in as the
first readings land instead of staying blank until reopened, and the browser
refetches the run and any comparison rather than the list behind them.
`retry --group` pages the list route by `before` instead of stopping at 500.
The terminal dashboard takes the terminal's colours (`ansi-dark`), and the web
UI can re-pair from Settings without disconnecting first.
The rate the media dtypes could carry was one frame every second or two: each
was a file on the data volume, an event on the socket, and a request back for
the bytes. This closes both halves of that, and they are one feature.
`save_artifact(..., volatile=True)` writes to a `VolatileStore` — the same
content-addressed store, in `/dev/shm`, bounded by size with the oldest falling
out (`ARTIFACT_VOLATILE_BYTES`, 48 MB under the container's raised `shm_size`).
Nothing sweeps it: a frame nobody kept is not worth walking the store to find.
`ArtifactStore.path` falls through to it, which is what lets a volatile frame be
an ordinary reference everywhere else — the dtype check, a panel's digest scope,
`load_artifact` in a node, and the widget's own fetch all work on one unchanged.
`adopt` copies one into the store when a run records it, so "returned media is
kept, emitted media is not" stays true.
The bytes then go down the flows websocket as a length-prefixed binary frame,
sent just ahead of the `message_value` naming them, so a tile has the frame when
it hears the value moved. Nothing is pushed unasked: a client names the messages
it is drawing (`{"type":"media","names":[…]}`), a panel's list is intersected
with the scope it already had, and only the newest frame per name in a batch is
sent — a client that fell behind is not handed frames it would draw over. The
tunnel relays text only, so a screen reached through a portal falls back to
fetching, which is why the rate table now has two rows.
Around the edges: the remote worker's fetch cache is bounded at last
(`FLUKSIO_ARTIFACT_CACHE_BYTES`), since content addressing means nothing in it
ever expires and a media stream fills it with chunks nothing asks for twice; a
port carrying an image draws the frame in the node panel rather than only
saying `image/png · frame.png · 1.79kB`; and an edge chip says that much instead
of a line of hash. The media screenshot stops waiting for `networkidle` — a
camera is a socket that never goes quiet, which is the point of it.
Follows the portal: the noun is "instance" everywhere the app says it —
UI strings, CLI output, error details, docs and comments. The wire keys
(`instance_id`, `instance_token`) and the hub route this calls move with it.
An existing cloud.json is adopted rather than refused: without the key
alias the dataclass fails to parse, which the caller swallows and reads as
"never enrolled" instead of "reconnect".
`instance_key` on a node type becomes `target_key`. It means the outside
thing a node points at, which is a different sense of the word, and keeping
both would put two meanings of "instance" in one codebase.
The log tee wrote through to the real stream unguarded, and the worker
pool tees a returned call's logs there after reading its result and
before handing it back — so a dead stdout, which `fluksio serve` makes
possible by running the engine as a child of the dashboard holding that
pipe, failed the node with its outputs already in hand. The capture half
runs first, so swallowing the write loses nothing.
Also: `flow_events` catches the RuntimeError a peer leaving mid-send
raises, which is a disconnect by another route, and the remote agent no
longer raises out of the task when its subprocess died before it could
be written to — the read below reports that and ends the call.
Melvin Strobl
stroblme