By default this plugin is active on every project. But you can skip its execution on some of them by setting the sonar.buildbreaker.skip property to true at project level. This property can also be set at instance level.
Property sonar.buildbreaker.forbidden.conf can be used to specify configurations that would break the build. For example, if you set in sonar administration GUI property sonar.buildbreaker.forbidden.conf to "sonar.gallio.mode=skip", each analysis on .net projects that would be executed with gallio skipped would be "broken"