Improve error message for distribution with no buckets [was: Stackdriver export is failing]

[census-ecosystem]

Improve error message for distribution with no buckets [was: Stackdriver export is failing]

[jeanbza]

Totally possible I'm trying to record time the wrong way. Is that the case? (related: census-instrumentation/opencensus-specs#44)

[odeke-em]

/cc @Ramonza @rakyll

[odeke-em]

@jadekler please firstly change this line https://gist.github.com/jadekler/5636acc62eb0048cad15206ef5587650#file-dupe_oc-go-L61
to

view.SetReportingPeriod(62 * time.Second)

to firstly rule out any hasty time series recordings as per #36 and census-instrumentation/opencensus-go#909

[semistrict]

@jadekler the problem is likely that you have no buckets in the distribution specified in the view.

[jeanbza]

@Ramonza What is a bucket? How do I get a bucket? Perhaps there's documentation that I'm lacking - if so, please feel free to link and close.

[songy23]

@jadekler The documentation is here: https://godoc.org/go.opencensus.io/stats/view#Distribution. The problem is although OpenCensus allows Distribution with no bucket bounds, Stackdriver doesn't support it.

Can you try modifying your view to something like:

func distView(m *stats.Int64Measure) *view.View {
	return &view.View{
		Name:        m.Name(),
		Description: m.Description(),
		TagKeys:     []tag.Key{subscriptionKey},
		Measure:     m,
		Aggregation: view.Distribution(0), // Should have at least one bucket bound.
	}
}

[jeanbza]

@songy23 Thanks for the pointers, I'll try this tomorrow or Monday. re:

The problem is although OpenCensus allows Distribution with no bucket bounds, Stackdriver doesn't support it.

Is it unreasonable to expect the stackdriver exporter to somehow raise an error, or panic, if that's the case?

[jeanbza]

Actually, we ended up going with a view with Aggregation: view.Sum(). I'll leave this open while we discuss the remaining question I had above.

[semistrict]

@jadekler to be fair, it did log an error, although I think we could certainly improve the error message by doing some basic validation client-side.

[jeanbza]

@Ramonza Actually, that's my fmt.Println heh. Is there a way to make opencensus verbosely log?

[semistrict]

The default if no OnError is provided should be to log the error, is this not happening? If not, could you send a PR with your changes to add the logging?

[jeanbza]

Ah, I was unaware of OnError. I'll leave y'all to decide if you want this issue as a placeholder for better docs, or if you'd like to just close it that's solid for me too.

[semistrict]

I think this could be handled by the same mechanism contemplated here: #19

[jeanbza]

SGTM