The start time must be before the end time for the non-gauge metric

[zargarpur]

The start time must be before the end time for the non-gauge metric

[zargarpur]

/assign @nilebox

[nilebox]

Looks like start and end times are the same, and Stackdriver rejects such counter?

AFAICT the start and end times are coming from the view.Data structure:

opencensus-go-exporter-stackdriver/stats.go

Line 249 in 1905f46

Points: []*monitoringpb.Point{newPoint(vd.View, row, vd.Start, vd.End)},

They are set in https://github.com/census-instrumentation/opencensus-go/blob/1901b56b9515b0c34f5d25a5bce982dfc543d64b/stats/view/worker.go#L352-L353

And there is a condition under which both Start and End will be set to "now":
https://github.com/census-instrumentation/opencensus-go/blob/1901b56b9515b0c34f5d25a5bce982dfc543d64b/stats/view/worker.go#L346-L349

This is likely what is causing the problem for you.

Potential ways to fix the issue:

• In opencensus-go: prevent setting both start and end times to "now" for non-gauges
• In opencensus-go-exporter-stackdriver: Implement some hack to add a nanosecond to make start and end times different - this may break the accuracy though
• In opencensus-go-exporter-stackdriver: Drop views which have equal start and end times - this leads to data loss

Not sure if there is a good way to fix that.

/cc @james-bebbington @rghetia

[ian-mi]

In opencensus-go, could start be set either during view registration or initial record?

[nilebox]

Currently, the startTimes map is initialized as empty and the initial startTime is set on the first export in https://github.com/census-instrumentation/opencensus-go/blob/1901b56b9515b0c34f5d25a5bce982dfc543d64b/stats/view/worker.go#L346-L349

We should be able to init start time when handling view registration in https://github.com/census-instrumentation/opencensus-go/blob/785d8992f1ac50097e9140accb05630e0eadfb5e/stats/view/worker.go#L295

[nilebox]

@zargarpur @ian-mi Feel free to send a PR with a fix to https://github.com/census-instrumentation/opencensus-go/ as described in #266 (comment), or I will get back to it myself within a few days.

[nilebox]

Released opencensus-go v0.22.4 with the bugfix.