Published: 27 Jun 2023
opentelemetryshould be used to instrument your code and possibly libraries. It doesn't communicate with anything except a backend (default: dummy backend)
opentelemetry-client-ocurlis a backend that communicates via http+protobuf with some collector (otelcol, datadog-agent, etc.)
[x] basic traces
[x] basic metrics
[x] basic logs
[ ] nice API
[x] interface with
[x] sync collector relying on ocurl
[x] batching, perf, etc.
[ ] async collector relying on ocurl-multi
[ ] interface with
logs(carry context around)
For now, instrument manually:
module Otel = Opentelemetry let (let@) f x = f x let foo () = let@ scope = Otel.Trace.with_ "foo" ~attrs:["hello", `String "world"] in do_work(); Otel.Metrics.( emit [ gauge ~name:"foo.x" [int 42]; ]); do_more_work(); () let main () = Otel.Globals.service_name := "my_service"; Otel.GC_metrics.basic_setup(); Opentelemetry_client_ocurl.with_setup () @@ fun () -> (* … *) foo (); (* … *)
The library is configurable via
Opentelemetry.Config, via the standard opentelemetry env variables, or with some custom environment variables.
OTEL_EXPORTER_OTLP_ENDPOINTsets the http endpoint to send signals to
OTEL_OCAML_DEBUG=1to print some debug messages from the opentelemetry library ide
OTEL_RESOURCE_ATTRIBUTESsets a comma separated list of custom resource attributes
This is a synchronous collector that uses the http+protobuf format to send signals (metrics, traces, logs) to some other collector (eg.
otelcol or the datadog agent).
This is a Lwt-friendly collector that uses cohttp to send signals to some other collector (e.g.
otelcol). It must be run inside a
The optional library
opentelemetry.trace, present if trace is installed, provides a collector for
trace. This collector forwards and translates events from
opentelemetry. It's only useful if there also is also a OTEL collector.
Not supported yet.