Will Jones
285add40dd
Bridges Lance's internal `metrics`-crate instrumentation (object store request counts, bytes, latency, errors, and throttles) into OpenTelemetry, in both the Python and Node bindings, with a shared adapter in the Rust core. This is the LanceDB counterpart to lance-format/lance#7537. ## Rust core (`rust/lancedb`) Two new, **off-by-default** features: - `metrics` — re-exports the [`metrics`](https://docs.rs/metrics) crate as `lancedb::metrics` and turns on Lance's object-store instrumentation. Install any `metrics`-compatible recorder to collect them. - `metrics-otel` — adds `lancedb::metrics_otel`, a pull-based adapter that installs a process-global recorder aggregating into lock-free cumulative storage and exposes a snapshot/catalog API (`register_metrics_recorder`, `metrics_catalog`, `snapshot_metrics`, `MetricPoint`/`MetricValue`/`MetricKind`/`MetricDescription`). Both bindings build on this. ## Python `lancedb.otel.instrument_lancedb_metrics()` registers each metric as an OpenTelemetry observable instrument on the given (or global) `MeterProvider`. Available via the `otel` extra (`pip install lancedb[otel]`), which pulls in only `opentelemetry-api` — the application supplies and configures the SDK. ## Node `instrumentLanceDbMetrics()` provides the equivalent wiring against `@opentelemetry/api`. This is the only public entry point; the underlying recorder/catalog/snapshot functions stay internal. Because OpenTelemetry has no asynchronous histogram instrument, histograms are exported Prometheus-style as `<name>_bucket` (with an `le` attribute), `<name>_count`, and `<name>_sum`. Only `_sum` carries the histogram's unit; `_bucket` and `_count` observe cumulative counts and are unitless. The adapter is enabled by default in the Python and Node builds, and off by default in the Rust crate. ## Notes - Requires Lance ≥ `v9.0.0-beta.19`, which ships the object-store metrics APIs (upstream lance-format/lance#7537, now merged). `main` is already on beta.19, so this is a single feature commit with no dependency bump. - Tests: 8 Rust unit tests, 3 Python tests, 2 Node tests, all covering the end-to-end object-store-metrics → OpenTelemetry path. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
LanceDB Documentation
LanceDB docs are available at docs.lancedb.com.
The SDK docs are built and deployed automatically by Github Actions
whenever a commit is pushed to the main branch. So it is possible for the docs to show
unreleased features.
Building the docs
Setup
- Install LanceDB Python. See setup in Python contributing guide.
Run
make developto install the Python package. - Install documentation dependencies. From LanceDB repo root:
pip install -r docs/requirements.txt
Preview the docs
cd docs
mkdocs serve
If you want to just generate the HTML files:
PYTHONPATH=. mkdocs build -f docs/mkdocs.yml
If successful, you should see a docs/site directory that you can verify locally.
Adding examples
To make sure examples are correct, we put examples in test files so they can be run as part of our test suites.
You can see the tests are at:
- Python:
python/python/tests/docs - Typescript:
nodejs/examples/
Checking python examples
cd python
pytest -vv python/tests/docs
Checking typescript examples
The @lancedb/lancedb package must be built before running the tests:
pushd nodejs
npm ci
npm run build
popd
Then you can run the examples by going to the nodejs/examples directory and
running the tests like a normal npm package:
pushd nodejs/examples
npm ci
npm test
popd
API documentation
Python
The Python API documentation is organized based on the file docs/src/python/python.md.
We manually add entries there so we can control the organization of the reference page.
However, this means any new types must be manually added to the file. No additional
steps are needed to generate the API documentation.
Typescript
The typescript API documentation is generated from the typescript source code using typedoc.
When new APIs are added, you must manually re-run the typedoc command to update the API documentation. The new files should be checked into the repository.
pushd nodejs
npm run docs
popd