[inputs.win_perf_counters] skip PdhCstatusNoInstance error

[hiroshi-iim]

Use Case

I plan to collect processes metrics on Windows host using configuration like below.

[agent]
  round_interval = true
  precision = "5s"
  interval = "5s"

[[inputs.win_perf_counters]]
  UseWildcardsExpansion = true

[[inputs.win_perf_counters.object]]
  UseRawValues = true
  ObjectName = "Process"
  Instances = ["OUTLOOK*", "python*"]
  Counters = [
    "ID Process",
    "% Processor Time",
]    

[[outputs.file]]
  files = ["stdout"]
  data_format = "csv"
  csv_timestamp_format = "2006-01-02T15:04:05Z07:00"

I tested this configuration with the following steps.

1. Start outlook and run python -c "while True: i=1".
2. Then start telegraf with above configuration.
3. Wait until telegraf outputs records for 1st interval.
4. Then Quit outlook.

Expected behavior

Telegraf continues to output records of running processes (matching "python*" in this case).

Actual behavior

Telegraf outputs error logs shown below and stops to output records until counters are refreshed.

E! [inputs.win_perf_counters] Error in plugin: error during collecting data on host "localhost": error while getting value for counter "\\\\{my computer name}\\Process(OUTLOOK)\\ID Process": The specified instance of the performance object was not found.

Additional info

I temporarily modified isKnownCounterDataError function to return true when errorcode is PdhCstatusNoInstance and ran same senario. In the case telegraf outputs warn logs shown below but continues to output records of python instance which has consistent value.

W! [inputs.win_perf_counters] Error while getting value for counter "\\\\{my computer name}\\Process(OUTLOOK)\\ID Process", instance: OUTLOOK, will skip metric: The specified instance of the performance object was not found.

Actually I have to set Instances = ["*"] in real case. In that case there are more chances to see PdhCstatusNoInstance error.

This is derived from #14486

[powersj]

@hiroshi-iim

Thanks for filing the second issue.

My only open question is if we should make this change opt-in, via a config setting. I don't think there is any harm in adding this and users would only be getting additional data, not less.

I have put up #14570 which incorporates both PRs. Could you confirm it gets the data for you?

Thanks!

[hiroshi-iim]

Hi @powersj

I don't think there is any harm in adding this and users would only be getting additional data, not less.

I completely agree with you.

I have put up #14570 which incorporates both PRs. Could you confirm it gets the data for you?

The new module works perfectly as expected.

Thanks!