Infiniband collector produces error noise

[SuperQ]

Host operating system: output of uname -a

Linux mrhankey 5.0.0-31-generic #33~18.04.1-Ubuntu SMP Tue Oct 1 10:20:39 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

node_exporter version: output of node_exporter --version

node_exporter, version 0.18.1 (branch: pr/1489, revision: 9f5225456d1312fa7720eda87f407cfcb2687466)
  build user:       ben@mrhankey
  build date:       20191008-12:51:33
  go version:       go1.13.1

node_exporter command line flags

./node_exporter

Are you running node_exporter in Docker?

No

What did you do that produced an error?

curl -s http://localhost:9100/metrics

What did you expect to see?

No errors

What did you see instead?

ERRO[0006] ERROR: infiniband collector failed after 0.000063s: error obtaining InfiniBand class info: failed to list InfiniBand devices at "/sys/class/infiniband": open /sys/class/infiniband: no such file or directory  source="collector.go:132"

[SuperQ]

Probably related to the refactor in #1396

[pgier]

Looks like #1396 changed the behaviour when there are no metrics available. Instead of returning nil, the error is returned. I can submit a PR to ignore missing data, but this seems to conflict with the proposal in #1323?

[SuperQ]

Good question, we should probably have a chat about how to deal with #1323.

[ww156]

how to resolve it?

[pgier]

As a workaround, you can just disable the infiniband collector.
--no-collector.infiniband

[AvengerMoJo]

@pgier so what is the final decision on the #1323 , should I just return nil without error? or return nil e.g. if the kernel module is not enable etc.

[pgier]

@SuperQ How common is it to use the infiniband metrics? I'm wondering if it should be disabled by default, and then enabled only by users that actually collect metrics for it.

[dswarbrick]

The contents of /sys/class/infiniband are not strictly limited to actual InfiniBand devices. On a few systems here, I also see i40iw devices there (Intel Ethernet X722 iWARP). I would also expect RoCE devices to appear there - basically anything that implements some flavour of RDMA.