Epic Goal

• Offer the option to double the scrape intervals for CMO controlled ServiceMonitors in single node deployments
• Alternatively automatically double the same scrape intervals if CMO detects an SNO setup

The potential target ServiceMonitors are:

• kubelet
• kube-state-metrics
• node-exporter
• etcd
• openshift-state-metrics

Why is this important?

• Reduce CPU usage in SNO setups
• Specifically doubling the scrape interval is important because:

1. we are confident that this will have the least chance to interfere with existing rules. We typically have rate queries over the last 2 minutes (no shorter time window). With 30 second scrape intervals (the current default) this gives us 4 samples in any 2 minute window. rate needs at least 2 samples to work, we want another 2 for failure tolerance. Doubling the scrape interval will still give us 2 samples in most 2 minute windows. If a scrape fails, a few rule evaluations might fail intermittently.
2. We expect a measureable reduction of CPU resources (see previous work)

Scenarios

1. RAN deployments (Telco Edge) are SNO deployments. In these setups a full CMO deployment is often not needed and the default setup consumes too many resources. OpenShift as a whole has only very limited CPU cycles available and too many cycles are spend on Monitoring

Acceptance Criteria

• CI - MUST be running successfully with tests automated
• Release Technical Enablement - Provide necessary release enablement details and documents.
• ...

Previous Work (Optional):

1. https://issues.redhat.com/browse/MON-1569

Open questions:

1. Whether doubling some scrape intervals reduces CPU usage to fit into the assigned budget

Non goals

• Allow arbitrarily long scrape intervals. This will interfere with alert and recoring rules
• Implement a global override to scrape intervals.