Custom Plugin Graphing Exponents and Calculations

Checkmk Exchange
,
1

CMK version:
OS version: CentOS 7

Creating a plugin with some metric data and struggling to find the correct method to handle a few items.
Given metric data coming from an agent like this:

<<<broadworks_as:sep(0)>>>
{"ValidResponses":26787,"AuthChallenges":26961}
<<<>>>

In a metric configuration file located in $OMD_ROOT/local/share/check_mk/web/plugins/metrics/ I have defined metric_info:

metric_info["AuthChallenges"] = {
    "title": _l("Auth Challenges"),
    "unit": "count",
    "color": "34/a",
}
metric_info["ValidResponses"] = {
    "title": _l("Valid Responses"),
    "unit": "count",
    "color": "34/b",
}

AND graph_info

graph_info["bw_as_auth_challenges"] = {
    "title": _l("BW AS Auth Challenges"),
    "metrics": [
        ("AuthChallenges,60,*", "line", _l("Auth Challenges per Minute")),
        ("ValidResponses,60,*", "area", _l("Valid Responses per Minute")),
    ],
    "scalars": [
        ("ValidResponses,AuthChallenges,/,100,*", _l("Percentage")),
    ],
}

Trying to mimic a legacy cacti graph like this
image

In the Check_MK graph configuration I have a few questions I can’t figure out.

  1. I can’t seem to find the right placement to specify the scale of the number as the “K/1000” like I see as an option in the units.py file. Currently checkmk is showing it as exponential value.
  2. Is a scalars the appropriate way to add a metric not on the graph? e.g. Percentages
  3. Can a comment be added to the graph similar to the vertical “Challenges per Minute” on cacti image?
  4. General question, is defining a metric_info considered good practices since I did figured out I can specify color and title inline with the graph_info:metrics values.

Current CheckMK Graph (dark mode)

image
image789×324 17 KB

Sincerely,
Scotsie

2

Not a dev, so can’t help on the concrete topics. @mschlenker is typically a good resource for such knowledge or good input for him for our dev guide.

Regarding 4) We are implementing a Graphing API at the moment, which will therefore also set best practices. This will come in 2.3, which will be released early 2024.

3

Thanks for the tagging and looking forward to the new guide. I did see the 2.2 breadcrumb mentioning ‘coming soon’.

It’s a bit frustrating because some other graphs under the same service are scaling and abbreviating the numbers as expected with nothing different between the configuration.

image
image789×359 17.9 KB

I imagine it’s due to the value size on the graph rendering but don’t know what I can do about it.

Sincerely,
Scotsie

4

Upon further review, I realized that in mimicking the cacti graph, the value is being multiplied by 60 to provide a /minute display value.

But there is a “1/s” (per second) unit available. I have modified the metric_info from

to

metric_info["AuthChallenges"] = {
    "unit": "1/s",
}

And removed the `,60,*’ from the graph_info metric line items.
That seems to be displaying a more readable unit of measure. Now to see if my internal customer demands the ‘per minute’ displayed value.

Sincerely,
Scotsie