Five concurrent training nodes, each sizing its thread pool to every core,
left the engine's own event loop unscheduled: the API stopped answering
within 10 s and every client died. The same shape on a GPU deadlocked a run
for 21 minutes at 0% utilisation with nothing failing and nothing to read --
it just sat in `running`.
@node(resources={"cpus": 2}) is the declaration. The engine holds that much
for the length of the execution, so more of them than the machine has room
for wait their turn rather than oversubscribing it, and a `gpus` node holds
its card exclusively. FLOW_CPUS defaults to every core but two, and those two
are what keeps the engine answering.
Because a thread cap is read when the process imports the library, a warm
worker cannot be told a different one -- so an environment gets a pool of its
own and nodes deriving the same one share it, rather than paying a cold start
per call on exactly the nodes whose imports are slowest. XLA_FLAGS is never
derived: it is a composed, version-dependent string, so it travels in
resources.env where it is visible.
A node that declares nothing is not accounted for and behaves as it always
did -- it just gets FLOW_CPUS/FLOW_MAX_WORKERS as a thread cap, which is the
half of this that fixes the reported incident without anybody declaring
anything. An operator who set OMP_NUM_THREADS themselves still wins.
Resources are claimed strictly before a worker slot, so the two blocking
waits cannot deadlock. A node queued for them publishes node_queued and shows
on GET /workers/resources, because waiting and hanging looked identical.
Accounted, not enforced: no cgroups, no rlimits. Scheduling across machines,
flavours and enforcement are the next steps.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Three faults with one root: the stored body of a code-defined node is an
import shim, and nothing that mattered was ever read from the code itself.
- The run stamp could not identify what ran. The shim imports whatever is on
disk when the worker starts, and an uncommitted tree stamps <commit>-dirty
for every run it ever produces. Run.code_digest hashes the repository's .py
files, memoized on their stat state, and it is read again when the run is
actually claimed -- so a sweep queued for hours records the code each of its
runs executed, not the code that was there when it was submitted.
- The stage cache adopted code that was too new. The fingerprint hashed the
shim, which is invariant under any edit to the imported function or anything
it calls into, so a re-run was served from cache and answered without the
outputs the edit added. It now carries the repo digest and the node's
declared ports. Every fingerprint changes once, which invalidates the
existing cache; a canvas flow has no repository and keys as before.
- An interrupted sync looked like a hand-edited canvas. The engine answers a
new-node template for a node with no stored body, and the template carries
no marker, so the drift check read "somebody edited this" and demanded
--force -- for the one state that re-running the sync is the fix for.
NodeSource.missing states the fact, and sync skips those and reuses the
bodies it read instead of asking for each one twice.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A driver script died of one slow answer: httpx.ReadTimeout out of
RunHandle.refresh() with a 30 s read timeout and no retry anywhere, which
cost a sweep 78 of its 84 runs.
- Split the timeout (5 s connect, 120 s read): a wrong URL fails at once,
and a busy engine gets longer than the slowest thing it does on purpose
(a 60 s compile, a 15 s rebuild wait).
- Retry idempotent calls three times on a transport error or 502/503/504.
503 is the engine's own "ask again" — it is what RebuildBusy answers.
- Submit carries a key the engine stores with the run, so a retry after a
timeout returns that run instead of starting a second. A sweep keys every
entry, so a half-created one recreates only what is missing.
- wait() and --follow tolerate five failed polls in a row; a 404 still stops
at once, because that is an answer rather than a gap.
- CLI says "engine not answering" and names the run still on the engine,
instead of printing a traceback.
- runs: clamp the params column to 80 characters; events() takes the
flow/since/until the endpoint already had; RunHandle.failures answers
"what killed this run" from the run's own node rows.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A code node in a batch run is now fingerprinted by its source, its raw
settings and the values it reads — an artifact input counting as its digest,
which is what the content addressing was always for. A run that finds the key
restores what the earlier one returned and skips the node, recorded as
`cached`. The run history is the cache: `run_node.outputs` beside the
`cache_key` the schema already had, no second store. On for code nodes, never
for the built-in and connector types that have side effects; off per node with
`@node(cache=False)` and per run with `--no-cache`.
Emissions are not replayed on a hit, so a cached training node returns its
result without redrawing its curve. Recorded in NOTEPAD.md with the two other
deliberate limits.
`fluksio run --local` boots the real app in the command's own process and
drives it through its ASGI interface behind the ordinary client, so a run no
longer needs a `serve` terminal beside it — same data directory, same history,
and the cache carries between the two. It always waits, because the engine it
starts lives exactly as long as the command.
Also: `fluksio sweep --param lr=0.1,0.01` for the product of the lists,
`run --follow` for a run's numbers as they arrive, Ctrl-C cancelling a waited
run rather than abandoning it, coloured statuses on a terminal, and `name`
made optional on the metrics endpoint so a follower can ask for every series.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
**The portal link puts itself back up.** It already retried a connection that
raised, but a session that ended *cleanly* — a portal restarting, a proxy
closing an idle socket — returned normally and went straight back round the
loop with no wait at all, so an engine could spin against a portal that was
merely saying goodbye politely. Every ending now reconnects on a delay, and
the delay turns on whether the attempt got as far as attaching: one that stood
up and dropped is a network event and retries at once, one that never stood up
waits longer each time. Jittered, so a portal coming back is not met by every
installation it serves in the same instant. Ping timeouts are named rather
than defaulted, since they are what bounds how long a suspended laptop's dead
socket looks alive, and the keepalive task is awaited so the reason a link
went reaches the log instead of the garbage collector.
**`fluksio enroll <code>`** is the whole command now; hub.fluksio.com is the
default and `--portal` names another. The one command run before anything
works should not need two flags.
**`fluksio run` syncs first.** The reason a run exists is usually the edit
before it, so remembering to sync was remembering to do something the computer
could do — including the worker refresh, which is what makes an edit to your
own package take effect at all. `--no-sync` opts out for a tight loop.
That last one needed discovery fixed: it only ever looked at top-level `*.py`,
so a repository whose code is in a package — the ordinary shape — found
nothing from its own root. It now descends into the packages it holds.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU
Two things a local install should not have asked for.
`fluksio serve` now signs you in. Logging in to your own machine was a
formality — the password was printed by the same process that would have
checked it, and the database it authenticates against sits in the directory
the token goes into — so `serve` mints the token itself and says where it put
it. `fluksio login` is left for an engine somewhere else.
And an installation is `.fluksio` beside the code, found the way `.git` is,
rather than one `~/.fluksio` for the machine. A repository with its own venv
was already getting its own engine; it now gets its own flows, run history and
token too, instead of three repositories sharing one database and fighting
over one port. `--global` asks for the shared one, `--data-dir` still names
any directory, and when both exist the banner says which you are looking at
and how to reach the other.
The directory ignores itself from within — a `.gitignore` of `*`, the way uv
writes one into `.venv` — because it holds a credential and a database, and
neither belongs in anybody's history. The token is written mode 600. A login
an older version wrote to ~/.config/fluksio is still read, so nothing that
worked stops working.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU
The workflow this serves: make a venv, install what you work with, then `pip
install fluksio` into the same one. Building a second environment beside it
was exactly wrong — the packages the nodes need are already here, and the
Modules screen was asking for them a second time.
`NODE_VENV=auto` (the default) adopts that venv. It declines in the three
cases where adopting would be wrong: `managed` says otherwise, a managed venv
already exists and may hold packages somebody installed on purpose, or the
engine is not running from a venv at all. The images set `managed`, since the
venv in them holds the app and nothing of anybody else's.
An adopted venv is never written to. `uv pip sync` makes a venv hold exactly
the manifest, so pointed at somebody's own environment it uninstalls their
work and the engine with it — `sync()` refuses outright and `reconcile()`
returns before it can be called at startup, which is where that would have
happened first. The Modules screen lists what is installed and drops its
editor; `pip` is how that environment changes.
`fluksio serve` now names the interpreter node code runs on, which is the
thing a data scientist most needs to know at that moment. `fluksio-worker`
already defaulted `--python` to its own interpreter, so a GPU box works the
same way — that was only ever undocumented.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU
A data scientist keeps their code where it is and decorates it: `@node`
declares a function's ports beside the function, `Flow(name, nodes=[...])`
says which of them make a flow, and `use(fn, wire=..., **settings)` rebinds
one for a single flow. `fluksio sync` uploads the document plus a generated
import shim per node, so the store still holds a complete, runnable,
git-versioned definition while the code it imports stays theirs.
`fluksio login|run|runs` and `flow.submit().wait()` are the client half, over
the run endpoints that already existed. Runs record the user repository's
commit beside the store's, so "what code produced this number" is answerable
on the side that now holds the code.
- `fluksio/sdk/`: ports, decorators, the flow builder and its checks, the shim
generator, an HTTP client and sync. Standard library only at import, so
`from fluksio import node` in a training script pulls in no engine.
- `FlowDef.origin` marks a flow code-defined; `Run.origin_commit` carries the
repository's commit; `POST /modules/refresh` retires the workers without an
install, which every sync calls — a worker holds the imported package in
memory, so an edit to it is invisible until the process goes.
- The canvas shows a generated body read-only and names the repository to edit
instead; a body edited there stops the next sync rather than being discarded.
- The worker's reporter carries inert `Port`, `node`, `use` and `Flow`, since
the shim imports a module whose first line declares them.
- `examples/myresearch` is the worked example, `make sync-example` uploads it.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012ue1tkFWB1bcGy3aWhCKpU
"What it can import is what the Modules screen installed" was true and
read as a wall: every example is a self-contained file, and a function
that imports half a repository looks unsupported. It is not — the
manifest is handed to `uv pip sync` verbatim, so `-e /home/you/repo`
installs the project you already have and a node becomes a three-line
wrapper over it. The code stays in your own repository, under your own
version control, importing its own siblings.
Two caveats that are easy to lose an afternoon to, so both are written
down: an editable install reaches the venv without a reinstall but not
into a worker that already imported it — the engine's workers are
long-lived, and Apply is what retires them, while an attached worker
starts a process per call and is always fresh. And the path is resolved
on whichever machine runs the node, while the manifest is committed to
the flow repository, so a laptop path means nothing in a container.
Verified rather than assumed: `uv pip sync` takes `-e`, the shim body
loads through the real `load_function`, an edit is live in a fresh
process and stale in a reused one.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The guide asked for a hostname and served the interface on
`app.${DOMAIN}` with the API on `api.${DOMAIN}` — which is not what
someone with a box in a cupboard sets up, and could not be made to work
by typing an address into a browser. `compose.lan.yml` already solves it
for the dev stack; the same file layers onto the production one, so the
guide now opens with that and keeps the hostname as the other option.
The reference gained the setting behind it. `VITE_API_URL` is a build
argument of the frontend image rather than something the stack reads,
which is worth saying once: empty means the interface addresses the API
relative to whatever origin served it, so one image answers on an
address, a hostname and an ssh tunnel alike, and no CORS list has to be
kept in step.
Verified against the production compose layered with `compose.lan.yml`:
the page, `/api` on the same port, a cross-origin-free login, the flow
websocket upgrading through nginx, and `/docs` still refused there.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A zensical site under docs/, served by a new `docs` compose service behind
Traefik, built with --strict in CI. Same pattern the sibling n3xd workspace
uses.
Getting started splits the way the landing page does — one path is
`pip install fluksio` and a training script, the other is a Docker stack and
an afternoon in the browser — because the two audiences will not spend the same
amount of time. Everything after that is shared: the concepts, the web
interface (app and portal), the CLI and the API, and a reference for node types,
payload types and configuration.
The three flow guides move here from the docs submodule rather than being
copied, so there is one version of them.
Styling mirrors DESIGN-GUIDELINES.md: the app's token palette remapped onto
Material's variables in both schemes, Inter, the 16px panel radius, and the one
terracotta accent spent on the facility lane of the audience split.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M7Xv3cJEW5c8AXxn2hoojV
stroblmeandClaude Opus 5