ClearML vs Jenkins

The open-source version is free and self-hostable. Hosted and enterprise tiers are paid.

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.

Very little — adding a couple of lines to an existing training script captures parameters, metrics and environment automatically.

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.

It covers MLflow’s tracking and adds orchestration, remote execution and data versioning. Whether that breadth is an advantage or extra weight depends on whether you need the rest.

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.

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.