Prometheus promises API stability within a major version, and strives to avoid breaking changes for key features. Some features, which are cosmetic, still under development, or depend on 3rd party services, are not covered by this.
Things considered stable for 2.x:
Things considered unstable for 2.x:
As long as you are not using any features marked as experimental/unstable, an
upgrade within a major version can usually be performed without any operational
adjustments and very little risk that anything will break. Any breaking changes
will be marked as
CHANGE in release notes.