Distributed Tracer Reservoir Limit Not Being Used

[tsmith-rv]

Reopened #600 as instructed since the latest Go Agent (v3.20.3) still has this issue:

Instead of the configurable distributed tracer reservoir limit, the defaultMaxSpanEvents is being used to determine whether or not to save a span event.

Description

go-agent/v3/newrelic/tracing.go

Line 416 in dd6e323

if len(t.SpanEvents) < defaultMaxSpanEvents {

When adding spans to a transaction, after you have added 2000 spans you are no longer able to add anymore, despite setting a higher reservoir limit using newrelic.ConfigDistributedTracerReservoirLimit(). This is because the defaultMaxSpanEvents constant is being used in the check, which is set at 2000. There is a note in the code expressing the need to replace this functionality.

go-agent/v3/newrelic/limits.go

Line 41 in dd6e323

// DEPRECATED: replaced with DistributedTracer.ReservoirLimit configuration value

Steps to Reproduce

Try to add more than 2000 spans to a transaction.

Expected Behavior

I would expect to see all the spans I instrumented in the code, up to the number I passed in to newrelic.ConfigDistributedTracerReservoirLimit().

[iamemilio]

Thanks for reporting, we are going to take a look at this and get a fix out as soon as we can.

[iamemilio]

A fix for this should be included in the 3.20.4 release.