Telegraf cloudwatch inputs throws errors like *E! [inputs.cloudwatch]: Error in plugin: no metrics found to collect*

[hflamboauto1]

Relevant telegraf.conf:

[[inputs.cloudwatch]]
  region = "eu-west-1"
  interval = "5m"
  namespace = "AWS/RDS"
  period = "1m"
  delay = "0s"

System info:

Telegraf 1.11.5

Steps to reproduce:

1. ... Add cloudwatch input to a region / namespace that has no activity e.g AWS/RDS with no running instances from a while.

Expected behavior:

Error message should be a WARN and not an ERROR and logged message would be great to have more info(s) like the relevant namespace and region of target cloudwatch input

I n case warn is found to not be useful .. then info would be great

Actual behavior:

Current

E! [inputs.cloudwatch]: Error in plugin: no metrics found to collect

Also would be very useful to output on message the relevant input namespace .eg AWS/RDS

Wanted

W! [inputs.cloudwatch]: Error in plugin: no metrics found to collect from namespace: AWS/RDS

Additional info:

2019-09-02T12:15:00Z E! [inputs.cloudwatch]: Error in plugin: no metrics found to collect

[glinton]

@danielnelson would this be better as a debug log?

[danielnelson]

Yes. For the extra logging info we should stick to the the new alias feature, since otherwise we would potentially need to add the entire plugins configuration in order for it to be identified.

[nwneisen]

I'd like to help with this.

I found where I can change this to a debug log and append the namespace before the error string is returned from the plugin. I'm now getting the desired output mentioned above.

@danielnelson can you explain what you meant by the new alias feature?

[danielnelson]

Can you open a pull request with the change you made?

On the alias feature, it is a new feature in 1.12 though isn't fully implemented on all plugins, might need master for this plugin. It works like this: set the alias using the alias option that works on all plugins:

[[inputs.cloudwatch]]
  alias = "myfavoriteplugin"

This will cause the logger to mention the alias, from memory it looks like:

E! [inputs.cloudwatch::myfavoriteplugin] Error in plugin...

It also adds a tag to the internal metrics from the plugin.

[nwneisen]

Thanks for explaining. Would you like to stick with the alias rather than adding the namespace to the error string?

PR is on the way. My first contribution to telegraf and I still need to go through the PR setup.

[danielnelson]

Yeah, let's use the alias rather than including the namespace. My thinking is that we don't want to get in the business of printing out the value of configuration option in order for it to be tied back to the plugin instance.

[nwneisen]

PR is in. I checked and alias is already implemented on this plugin.