Since v0.75.0, the hostmetricsreceiver emits metrics with empty string attribute values

[jacobmarble]

Since otelcol-contrib v0.75.0, the hostmetrics receiver is emitting metrics with empty string attribute values, such as device = string(""). I've confirmed that this behavior started in v0.75.0.

I'm not certain that empty attribute values are disallowed in the otel spec, but the influxdbexporter has rejected empty attribute values since it has existed.

Originally posted by @jacobmarble in #21474 (comment)

Steps to Reproduce:

otelcontribcol config:

receivers:
  hostmetrics:
    collection_interval: 1s
    scrapers:
      cpu:
      memory:
      filesystem:
      paging:
      process:
        metrics:
          process.cpu.time:
            enabled: false
          process.memory.utilization:
            enabled: true

exporters:
  file:
    path: /tmp/metrics.json

service:
  pipelines:
    metrics:
      receivers: [hostmetrics]
      exporters: [file]

Run for a few seconds, then stop and search the resulting metrics:

$ jq '.. | select(type == "object" and has("key") and has("value") and .value == {"stringValue": ""})' /tmp/metrics.json
{
  "key": "device",
  "value": {
    "stringValue": ""
  }
}
{
  "key": "device",
  "value": {
    "stringValue": ""
...

Where "stringValue": "", the influxdbexporeter fails. (After #21526 is merged, the influxdbexporter will drop the offending attribute and emit a Debug log.)

[jacobmarble]

/label receiver/hostmetrics

[atoulme]

Do you have a reproduction scenario? That would help to see where the bug is.

[jacobmarble]

Do you have a reproduction scenario? That would help to see where the bug is.

Of course! Updated the original comment.

[github-actions]

Pinging code owners for receiver/hostmetrics: @dmitryax. See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• receiver/hostmetrics: @dmitryax

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• receiver/hostmetrics: @dmitryax

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.

[evilr00t]

hostmetrics with the process exporter still sends out empty labels, Thanos ain't happy about it - would suggest to re-open?