topic How to display 100% degradation in SLO? in Dashboarding

How to display 100% degradation in SLO?

vvasudev — Thu, 22 May 2025 07:33:57 GMT

Hi,

I'm new to Dynatrace and I'm currently working on setting up monitoring in non production environment that will eventually move to production. Currently, I'm trying to create a SLO for a span that we intentionally ran to have a failure rate of 100%. However, the SLO is not able to evaluate it.

DQL that I'm using:

fetch spans | filter matchesValue(endpoint.name, "<endpoint_name>") AND matchesValue(entityAttr(dt.entity.process_group, "tags"), "*APISECCluster*") | fields start_time, end_time, Tier, span.name, duration, span.status_code, endpoint.name | makeTimeseries { EPM = countIf(span.status_code == "error", default: 0), CPM = count(default: 0) }, by: { API=endpoint.name } | fieldsAdd sli=(((CPM[]-EPM[])/CPM[])*(100)) | fieldsAdd API

Since its a 100% failure rate - sli=(((CPM[]-EPM[])/CPM[])*(100)) will be 0%, which is not being displayed correctly and not being reported in the 'Problems' app in DT. Is there a way to handle this scenario where 100% degradation (which resoluts in 0% sli) will be recognized by DT? Thanks in advance!

Re: How to display 100% degradation in SLO?

Michal_Gebacki — Thu, 27 Nov 2025 15:25:20 GMT

Hi, @vvasudev!

Is this documentation page helping to resolve challenge you've described above: add a service-level objective (SLO) tile to a dashboard?

Please let us know, thank you in advance!

Re: How to display 100% degradation in SLO?

t_pawlak — Fri, 28 Nov 2025 15:05:28 GMT

Hi,
You’re running into two things at once: DQL behavior and SLO evaluation rules.
Try this DQL so the SLI is always a valid number (no division-by-zero edge cases):

fetch spans | filter matchesValue(endpoint.name, "<endpoint_name>") | makeTimeseries { EPM = countIf(span.status_code == "error"), CPM = count() }, by: { API = endpoint.name } | fieldsAdd sli = if(CPM[] > 0, then: ((CPM[] - EPM[]) / CPM[] * 100), else: 0)

In the SLO configuration, enable the option that allows evaluation when SLI = 0% (wording like “evaluate SLO even if SLI equals 0%” / “don’t suppress zero-value SLI”).

Once that’s set, a 100% failure rate → SLI = 0% will be treated as a valid SLO breach and will show up in Problems.