feat: implement tracing without composition #30
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Tracing with composition is tricky for OONI because we sometimes have a DoH resolution (so two HTTP round trips) before a real HTTP round trip when we're using a DoH resolver. In such a case, tracing with composition complicates attributing the correct connection to the request that's using it. This happens because the whole chain of operations is using the same context.Context, so we end up attaching three traces to the context (one per round trip). Conversely, if traces do not compose, each round trip gets its own Trace and we should be able to bind connections and requests. Because ooni/oohttp is experimental and will always be experimental, I don't feel bad about adding this API for experimentation and for our own sake. The original API is still there, so it all feels ~fine. I will revert this commit if the experiment fails 😬. Reference issue: ooni/probe#2220
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Tracing with composition is tricky for OONI because we sometimes have
a DoH resolution (so two HTTP round trips) before a real HTTP round trip
when we're using a DoH resolver.
In such a case, tracing with composition complicates attributing the
correct connection to the request that's using it. This happens because
the whole chain of operations is using the same context.Context, so we
end up attaching three traces to the context (one per round trip).
Conversely, if traces do not compose, each round trip gets its own
Trace and we should be able to bind connections and requests.
Because ooni/oohttp is experimental and will always be experimental, I
don't feel bad about adding this API for experimentation and for our
own sake. The original API is still there, so it all feels ~fine.
I will revert this commit if the experiment fails 😬.
Reference issue: ooni/probe#2220