🐛 [Bug]: OTeL duplicate and wrong counter metrics are generated infinitely about contrib

[pellared]

This is incorrect usage of Fiber.

See https://pkg.go.dev/github.com/gofiber/fiber/v2#Ctx.Params

Returned value is only valid within the handler. Do not store any references. Make copies or use the Immutable setting to use the value outside the Handler.

[efectn]

I think this issue can be moved to contrib repo.

[pellared]

Sorry I accidently send a comment when I was answering here open-telemetry/opentelemetry-go#4563 😉

Can you share the line you are referring to?

The issue is here: https://github.com/oliverdding/otel-test/blob/1bb67cf571d89d836d20b44f6278ae166a008d6b/cmd/server/main.go#L132-L136

You should make a copy of appID in the handler as the metrics are exported asynchronously.

appID = strings.Clone(appID)
requestCount.Add(c.UserContext(), 1, metric.WithAttributes(attribute.String("app_id", appID)))

[oliverdding]

Oh😢, it's my fault...

Thanks for pointing out @pellared

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[oliverdding]

@efectn I have reported an related issue there: open-telemetry/opentelemetry-go#4563

[ReneWerner87]

This is incorrect usage of Fiber.

See https://pkg.go.dev/github.com/gofiber/fiber/v2#Ctx.Params

Returned value is only valid within the handler. Do not store any references. Make copies or use the Immutable setting to use the value outside the Handler.

Can you share the line you are referring to?