mirror of
https://github.com/simonw/datasette.git
synced 2026-09-03 15:14:08 +02:00
1052dc5c7b
The span reference itself is generated from the registry, so this adds the prose the generated list cannot supply: how to actually see a span, what is deliberately never recorded, and where the instrumentation stops short. The "how to turn it on" part is the part people get wrong. Core installs no provider, so OTEL_TRACES_EXPORTER=console against a plain `datasette` process emits nothing at all - that variable is read by the SDK auto-configuration which only runs under `opentelemetry-instrument`. Documented as a warning because it reads like a bug when you hit it. Two more measured facts get the same treatment: the SDK's BatchSpanProcessor default schedule delay is 5000ms (checked, not assumed - `BatchSpanProcessor._default_schedule_delay_millis()` on opentelemetry-sdk 1.44), so nothing appears for five seconds; and without OTEL_SERVICE_NAME the default resource reports service.name=unknown_service. Privacy properties are stated positively rather than left implicit: SQL truncated at 2048 characters, parameter values never recorded, no actor identifiers, table names only from an explicit `table=` argument. The last of those is now documented on db.execute() itself, since it is public API. The limitations section claims only what was measured. An earlier draft said two traces per process are orphaned by the register_output_renderer and asgi_wrapper hooks; measuring it showed a default install emits zero spans from either, because Datasette queries no database there - it is a plugin that would produce the orphan. Corrected to say that. It also deliberately does NOT say an embedder must install its provider before Datasette's first span or get nothing. That claim is false: ProxyTracer._tracer returns the no-op tracer without caching it when no provider is set, so early spans are dropped and nothing is poisoned. The telemetry.py docstring said no-op spans "cost approximately nothing". The benchmark for this diff does not support a claim that strong - a table page emits ~58 spans - so it now states the measurement instead: median 9.80ms to 9.98ms across 15 runs, inside a 1.4ms run-to-run spread. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> |
||
|---|---|---|
| .. | ||
| _static | ||
| _templates | ||
| .gitignore | ||
| authentication.rst | ||
| auto-build.sh | ||
| binary_data.rst | ||
| changelog.rst | ||
| cli-reference.rst | ||
| codespell-ignore-words.txt | ||
| conf.py | ||
| configuration.rst | ||
| contributing.rst | ||
| csv_export.rst | ||
| custom_templates.rst | ||
| datasette-0.51.png | ||
| datasette-logo.svg | ||
| deploying.rst | ||
| ecosystem.rst | ||
| events.md | ||
| facets.rst | ||
| full_text_search.rst | ||
| getting_started.rst | ||
| index.rst | ||
| installation.rst | ||
| internals.rst | ||
| introspection.rst | ||
| javascript_plugins.rst | ||
| json_api.rst | ||
| json_api_doc.py | ||
| Makefile | ||
| metadata.rst | ||
| metadata_doc.py | ||
| pages.rst | ||
| performance.rst | ||
| plugin_hooks.rst | ||
| plugins.rst | ||
| publish.rst | ||
| settings.rst | ||
| spatialite.rst | ||
| sql_queries.rst | ||
| telemetry_doc.py | ||
| template_context.rst | ||
| template_context_doc.py | ||
| testing_plugins.rst | ||
| upgrade-1.0a20.md | ||
| upgrade_guide.md | ||
| writing_plugins.rst | ||
