Hello Robert, You probably want to use the DS support  for the **NEW** _Condition Service Specification_ which was added in OSGi Compendium R8 (currently in the release process).
You can try this out with the current 2.2.0-RC1 of Felix SCR  on Maven Central. The Condition Service Specification lets you model your application conditions (as the name implies) using OSGi service filters.  https://osgi.github.io/osgi/cmpn/service.component.html#service.component-satisfying.condition  https://search.maven.org/artifact/org.apache.felix/org.apache.felix.scr/2.2.0-RC1/bundle On Tue, Oct 12, 2021 at 5:50 AM Robert Munteanu <romb...@apache.org> wrote: > Hi, > > I have written a couple of small OSGi apps where if a single top-level > DS component, let's call it T, cannot start then the application should > shut down immediately. One example are HTTP services where the HTTP > server port cannot be bound to. > > The causes of failures I have seen are: > - T activation fails > - the bundle providing T fails to resolve > - a dependency of T fails activation > - a dependency of T cannot be provided because the bundle providing it > failed to staret > > I can think of several ways of approaching the problem, but none of > them perfect: > - using the Felix Health Checks, that seems wrong since it's a > polling-based approach and we very likely know when a dependency fails > and stop immediately > - using the SCR introspection API , which is again based on polling > - waiting for the framework to start and then looking up the service; > but we don't know when the SCR has 'settled' > > Are there any patterns or libraries that I can use to approach this > problem? > > Thanks, > Robert > > : > > https://felix.apache.org/documentation/subprojects/apache-felix-healthchecks.html > : > https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.component.html#service.component-introspection > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@felix.apache.org > For additional commands, e-mail: users-h...@felix.apache.org > > -- *Raymond Augé* (@rotty3000) Senior Software Architect *Liferay, Inc.* (@Liferay) OSGi Fellow, Java Champion