Option
trace of project
Which traces of the app are kept, and where they are sent out. A trace is the tree of timed spans of one thing that happened: a request, a press on a page with all it set off, a run, a task on a worker.
Value
{ share, otlp }. share is the part of the traces that is kept where nothing in them asks it, from 0 to 1, chosen by the id of the trace, so that every machine keeps the same ones: 0.1 on live data and 1 on test data where it is left out. A trace that holds an error, or a span longer than limits.slowSpan (500 ms), is kept whole whatever the share says. Spans are kept for limits.traceKeep (7 days), in the table spans of the log.
otlp names an address that takes the OpenTelemetry protocol over HTTP, { url, headers? }, each a text, a setting or a secret. The engine sends the spans it keeps there in batches, to <url>/v1/traces, and the lines and errors of the log to <url>/v1/logs, each with its trace, through the guarded fetch. What cannot be sent stays in the log, and is not tried again once it is older than limits.traceKeep.
A span holds names, counts, sizes, times and codes, and never an input, an answer, a value of a row, a secret, a token or a cookie, so a trace may be sent where the data of the app may not.
Example
export const shop = project('shop', {
trace: { share: 0.2, otlp: { url: setting('otlpUrl'), headers: { authorization: secret('OTLP_TOKEN') } } },
})Errors
code.T1014: a share that is no number from 0 to 1.