automatic restart of services
After installing security updates, it is necessary to restart the affected services to get rid of the vulnerabilities present in previous versions of the packages. Currently, apk provides no means for doing this automatically. A decent implementation of this functionality would take shared library dependencies into account.
One possible implementation finds the transitive closure of the updated packages, where the transitive relation follows the package dependencies in the reverse direction. Then each init script owned by any package in the closure is invoked with the restart command if the respective service is running.
(from redmine: issue id 2251, created on 2013-09-12, closed on 2019-06-19)