Project: mesos
Issue MESOS-3934: Libprocess: Unify the initialization of the MetricsProcess and ReaperProcess
Related to this [TODO|https://github.com/apache/mesos/blob/aa0cd7ed4edf1184cbc592b5caa2429a8373e813/3rdparty/libprocess/src/process.cpp#L949-L950]. The {{MetricsProcess}} and {{ReaperProcess}} are global processes (singletons) which are initialized upon first use. The two processes could be initialized alongside the {{gc}}, {{help}}, {{logging}}, {{profiler}}, and {{system}} (statistics) processes inside {{process::initialize}}. This is also necessary for libprocess re-initialization.
Story points: 3