The API embeds every query it serves, so it held its own copy of the model:
~890 MB it never needed. EMBEDDINGS_DELEGATE_TO_WORKER (on by default) sends
the text to the Celery worker instead and gets the vector back, taking an API
process from 1176 MB to 285 MB with no ONNX Runtime imported at all. The client
embeds locally when it finds itself inside a worker task, so the worker never
dispatches to itself -- the same self-deadlock DOCUMENT_PARSE_QUEUE avoids on
the parsing side. EMBEDDINGS_BASE_URL still wins over it, and remains the right
answer for production.
ensure_vector_schema was constructing the embeddings instance purely to read
.dimension off it, loading several hundred MB of ONNX into every API and worker
process at import. For a model the registry describes that is a lookup; only an
unregistered name now falls back to loading.
EMBEDDINGS_BATCH_SIZE was sizing two unrelated things: chunks per store
transaction (and per remote embed request) and documents per ONNX forward pass.
Each pass pads every input up to its longest, and that waste grows with the
square of chunk length, so at the 1250-token default a batch of 32 peaked at
6.6 GB and took 326s where a batch of 1 peaked at 2.9 GB and took 90s. The
forward pass is now sized by EMBEDDINGS_MODEL_BATCH_SIZE, defaulting to 1;
storage and remote batching are unchanged at 32.
reembed embeds in-process: a batch job that walks the whole index should not
round-trip every chunk through a broker, and loading the model there reports a
real failure instead of timing out against an empty queue.
Also drops the mpnet zip download from the docs and the devcontainer, which
pointed at a SentenceTransformers export with no ONNX graph and had been inert
since the FastEmbed swap; corrects the claim that any sentence-transformers
model works; and settles the Configuring/Settings pages on what the registry
and the repository metadata actually decide.
Follow-up review pass over the embeddings branch.
- Fold an oversized header back into the body, and drop header duplication
when it would leave under a quarter of the chunk budget. A header at or
over max_tokens collapsed the body budget to one token, so a document
became one chunk per body token, each still over the cap: a 95 KB file
produced 20k chunks of 2563 tokens against a 1250 cap. Also clamp
max_tokens to at least 1, as the strategy chunkers already do.
- Emit a header-only document as its own chunk. With no body piece to
attach it to, splitting returned nothing and the document was dropped
from the index with no error and no log line.
- Skip add_custom_model for a repository FastEmbed already ships. It
rejects a name it knows, so configuring any of its ~30 built-ins
(MiniLM, bge, e5, gte, ...) failed every embed call and every query.
- Decide "the user chose this model" by comparing against the field
default rather than model_fields_set, which is true for anything read
from .env. Every setup script has always written EMBEDDINGS_NAME, so an
upgraded remote-embeddings install inherited mpnet's 384-token window
and silently clipped ~80% off every chunk.
- Cut tiktoken splits at character offsets instead of decoding each token
window. A multi-byte character straddling a boundary decoded to U+FFFD
on both sides, destroying one character at roughly one boundary in five
on CJK text -- including at the default max_tokens of 2000.
- Let the re-embed script open a FAISS index whose width does not match
the configured model. That mismatch is the main reason to run it, and
the error recommending the script was raised by the script itself, so
the advice failed on every source.
- Re-embed graph_nodes.name_embedding when GraphRAG is enabled. Those
vectors seed every traversal and share the chunk vectors' width, so a
same-width model swap left the graph retrieving from the old space with
nothing to report it.
- Prefetch the models before copying the application source, so editing
any file no longer re-downloads ~780 MB of artifacts on every build.
- Mirror the setup.sh embedding menu into setup.ps1: granite default,
legacy mpnet as an explicit option, and both engine flows updated.
Windows users were otherwise stranded on mpnet with no granite path.
- Drop the unused EmbeddingsWrapper.tokenizer property.
Follow-up to the embeddings work, from a review pass over the branch.
- Route the OpenAI/Azure key handling through the model registry instead of
matching the canonical name literally, so the `text-embedding-ada-002`
alias the registry now accepts also reaches the Azure deployment name
rather than failing every embed with DeploymentNotFound.
- Fall back to a default width where the embeddings model reports no
dimension. A model outside the registry returns None rather than no
attribute, so `getattr` with a default did not catch it and the width
reached the DDL as `vector(None)` / `list_size=None`.
- Point HF_HUB_CACHE at the prefetch directory. Chunking loads the tokenizer
through `tokenizers`, which reads the hub cache, so a fresh container
fetched over the network on first ingest and an offline one silently fell
back to cl100k.
- Charge a token that collapses a long unbroken run by its character span.
WordPiece emits one [UNK] for any word over its character limit, which made
base64 and minified content count as near-zero tokens, so nothing split it
and oversized chunks reached the embedding server.
- Preserve chunk ids and honour --batch-size when rebuilding a FAISS index.
Fresh uuids orphaned GraphRAG's graph_node_chunks rows, and the whole index
went out in a single embed call on remote servers.
- Document that granite runs an int8-quantised graph, and scope the
SentenceTransformer parity claim to mpnet's fp32 graph, which is where it
was measured.
- Correct the embeddings docs: a matching dimension is not a matching model,
so a same-width swap raises nothing and silently degrades retrieval.
Alex