Carbon receiver drops metrics with float timestamps

[jonnangle]

Component(s)

receiver/carbon

What happened?

Description

The carbon receiver expects an integer timestamp, and will raise an error if a float is provided:

collector-1   | 2024-02-16T12:08:20.276Z	debug	carbonreceiver@v0.94.0/reporter.go:60	Carbon translation error	{"kind": "receiver", "name": "carbon", "data_type": "metrics", "error": "invalid carbon metric time [my.metric 151 1708085258.254]: strconv.ParseInt: parsing \"1708085258.254\": invalid syntax"}

This is causing us some issues, as we have carbon clients that are providing a float timestamp. The carbon protocol does suggest that an integer Unix timestamp should be used, but there is some prior art for allowing a float (which is why this has been working for us up until now!):

• https://github.com/graphite-project/carbon/blob/66ebee19ece0e59d6a802d0ff77bead02191b7ab/lib/carbon/protocols.py#L196-L197
• https://github.com/go-graphite/go-carbon/blob/master/receiver/parse/plain.go#L41-L46
• https://github.com/prometheus/graphite_exporter/blob/8e5d197e521c0dac49bbb38b61e6197b3c28f947/collector/collector.go#L169-L173

Steps to Reproduce

Send a carbon plaintext metric with a float timestamp, e.g. my.metric 151 1708085258.254

Expected Result

The timestamp is accepted as if it were an int.

Actual Result

An error is raised and the metric is dropped.

Collector version

0.94.0

Environment information

Environment

Using opentelemetry-collector-contrib docker image

OpenTelemetry Collector configuration

No response

Log output

collector-1   | 2024-02-16T12:08:20.276Z	debug	carbonreceiver@v0.94.0/reporter.go:60	Carbon translation error	{"kind": "receiver", "name": "carbon", "data_type": "metrics", "error": "invalid carbon metric time [my.metric 151 1708085258.254]: strconv.ParseInt: parsing \"1708085258.254\": invalid syntax"}

Additional context

No response

[github-actions]

Pinging code owners:

• receiver/carbon: @aboguszewski-sumo

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[crobert-1]

Resolved in #31313