Checkmk vs Jenkins

Yes, Checkmk Community edition is free forever and supports up to approximately 100 hosts for basic infrastructure monitoring with no cost.

When the build needs something hosted runners cannot give you: physical hardware, an air-gapped network, a node-locked commercial tool licence, or an unusual platform. If none of those apply, hosted CI is usually less work to own.

Checkmk uses service-based pricing where each monitored aspect (file system, hardware sensor, switch port, metric) counts as one service. On average, there are approximately 30 services per host.

Not in the open source distribution, which runs a single active controller. High availability and active-active controllers are features of CloudBees' commercial products. Open source deployments mitigate it with fast restores and, sometimes, multiple independent controllers.

Pro tier at 190 EUR/month includes advanced analytics and 8x5 support, while Ultimate at 275 EUR/month adds full-stack observability, advanced compliance features, and upgradable 24/7 support.

This is the main operational risk. Many plugins have a single volunteer maintainer, and Jenkins publishes security advisories for unmaintained plugins where no fix exists. Auditing which plugins you depend on and who maintains them should be a periodic task, not a one-off.

Yes, Checkmk CloudAI is a fully managed SaaS tier at 240 EUR/month with 99.5% uptime SLA and support for up to 50000 services.

For declarative pipelines you can go a long way without it. Anything involving shared libraries, conditional logic or custom steps is Groovy, and it runs in a sandboxed, transformed environment where standard Groovy idioms sometimes behave unexpectedly.

The software is free under the MIT licence. The cost is infrastructure and staff time to run controllers, agents and upgrades, plus a CloudBees subscription if you want high availability, support or centralised management of many controllers.