feat(nodejs): minimize out-of-the-box supported propagators to reduce coldstart delay #1664
Conversation
| process.env.OTEL_PROPAGATORS.trim() === '' | ||
| ) { | ||
| return new CompositePropagator({ | ||
| propagators: [ |
There was a problem hiding this comment.
Could you clarify why the default propagators will not match the ones listed here? https://github.com/open-telemetry/opentelemetry-lambda/blob/main/nodejs/packages/layer/scripts/otel-handler#L12
Also if the defaults are already set in otel-handler, is there any reason to also set it here? (I actually prefer that to be here instead)
There was a problem hiding this comment.
@pragmaticivan Because this is the existing behavior.
Currently, propagators are taken from here in the @opentelemetry/auto-configuration-propagators package and hence I used the impl/logic there.
There was a problem hiding this comment.
But the defaults of this project are tracecontext,baggage,xray instead. This env variable will always be overwritten by that file, so the code will never hit that block
There was a problem hiding this comment.
- without this PR, default propagators (tracecontext,baggage,xray) are set by the
otel-handlerscript - with this PR, still default propagators (tracecontext,baggage,xray) are set by the
otel-handlerscript
So, this keeps the existing behavior. No need to put the same default list into the newly introduced getPropagator method too. otel-handler script is responsible for setting the defaults.
There was a problem hiding this comment.
I really don't understand the issue here. This PR keeps the existing behavior for propagators by default because it uses the existing impl code. Why it was OK before, and NOT OK now?
There was a problem hiding this comment.
I guess you are trying to replicate the other package behavior here when you might not need this code block. All good, though. I understand that this was the default from the other package, yet this is a block of code that will never be able to be reached in this package, which makes it dead code out of the gate
There was a problem hiding this comment.
No one can guarantee that this is dead code even though otel-handler is in place.
Because users might put their own initializers and activate it through the NODE_OPTIONS env var. And in this case, their initializers will run before our wrapper. So, potentially, they can clear the OTEL_PROPAGATORS env var in their initializer code, hence wrapper should take care of empty OTEL_PROPAGATORS env var too.
There was a problem hiding this comment.
Makes sense, I guess I see the point of this code, but don't see the point of keeping that code in otel-handler 😂
There was a problem hiding this comment.
If you are still interested in removing that code block, you can send another PR for it and we can discuss. But the main point of this PR is dropping b3 and jaeger propagator dependencies without changing existing behavior.
… coldstart delay (open-telemetry#1664) * feat(nodejs): minimize out-of-the-box supported propagators to reduce coldstart delay * add tests * feat(nodejs): get rid of `@opentelemetry/sdk-trace-node` package dependency * add more tests
3 participants
and additionally, this PR
@opentelemetry/sdk-trace-nodeto be not dependent to the@opentelemetry/propagator-b3and@opentelemetry/propagator-jaegerpropagator packages.@opentelemetry/sdk-trace-nodedependency) expands the required types can be passed to theconfigureTracerProviderandconfigureTracerfunctions. Since this is type expansion, it should not break backward compatibility, because lower types (NodeTraceProviderandNodeTracerConfig) can still be passed to these functions as is.