Clarify named tracers and meters #76
Conversation
Co-Authored-By: Christian Neumüller <[email protected]>
dyladan
requested review from
AloisReitbauer,
bogdandrutu,
c24t,
carlosalberto,
iredelmeier,
jmacd,
reyang,
SergeyKanzhelev,
songy23,
tedsuo,
tigrannajaryan and
yurishkuro
as code owners
dyladan
changed the title
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I would like to propose that we rename this feature something other than "Named" interfaces. As we have learned--a number of people mis-interpreted this feature to be about providing a namespace for the spans and metrics created through the "Named" interface. The intention of this feature is to supply the "library name" and optional version. While the library does have a name, the library name and version are used here for identification, not the form of naming that many implementors assumed. I would call this feature Obligatory Reporter Identification. |
I'm also fine with the 'Reporter' wording and we discussed a possible rename but we didn't want to create more confusion by renaming the thing while clarifying its intent. |
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@jmacd To me Obligatory Reporter Identification sounds a bit bulky but I see that it would certainly make the intent clearer than Named Tracer/Meter, even though the latter is already an established name for it. Would you prefer to rename the provided parameter from instrumentation library to either reporter or reporting library, or would you keep it as it is? I agree with @danielkhan's reasoning above. |
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I'd also slightly prefer to have this feature renamed to something other than Named Tracers. Approving, otherwise this looks great. |
Some other names were floated but nothing has really stuck. |
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@open-telemetry/specs-approvers Please review and offer feedback or approve. |
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| If no name (null or empty string) is specified, following the suggestions in ["error handling proposal"](https://github.com/open-telemetry/opentelemetry-specification/pull/153), a "smart default" will be applied and a default Tracer / Meter implementation is returned. | ||
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| ### Examples (of Tracer and Meter names) | ||
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| Since Tracer and Meter names describe the libraries which use those Tracers and Meters, their names should be defined in a way that makes them as unique as possible. | ||
| The name of the Tracer / Meter should represent the identity of the library, class or package that provides the instrumentation. | ||
| The name of the Tracer / Meter should represent the identity of the library, class or package that provides the instrumentation. |
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Just a small clarification, is the name the key that identifies the Tracer/Meter or name + version? What is the expected behavior when (I don't know how is it possible) there are 2 requests to the getTracer with same name and different versions?
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Currently unspecified. In the javascript version, you get a different instance of tracer per name-version pair, but you could conceivably get a new tracer every time getTracer is called. Do you think that needs to be specified? Since the tracer delegates all its configuration to the TracerProvider, it doesn't really matter if you make a new one per name, new one per name/version pair, new one every time, or just 1 instance of each tracer type (noop or working).
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My suggestion is to work on this detail in the actual Specification, as this OTEP has been approved and is ready to merge.
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I think it is important mainly for the metrics side. One important thing we need to ensure the name of the metrics are unique inside a "component" (instrumentation library), so if the component is identified by the name then I need to keep a list of all the registered instruments at the name level vs at the name+version level.
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Will close/reopen to re-trigger CLA check. |
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This is ready to merge, right? |
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Merged, thanks - as a further reminder, please address the last question by Bogdan (about name/version identity) when writing the actual specification side, as it might need further refinement. |
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@jmacd @carlosalberto I was not sure if this is ready since I raised one issue and I didn't hear back any comment. Not a problem that it is merged but was waiting for that response. |
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@bogdandrutu I see, I thought I was agreed this would be tackled when writing the specification side, my bad. Opened an issue to keep track of this when @dyladan (or anybody else) includes this OTEP into the Specification: open-telemetry/opentelemetry-specification#434 |
Based on conversations with SIGs, especially the specification, the overall motivations and use cases of named tracers seem to be poorly understood.
This change attempts to clarify the named tracer OTEP in order to address some of that confusion. It also adds a glossary of terms at the bottom in order to aid in that disambiguation.