Project: mesos
Issue MESOS-3132: Allow slave to forward messages through the master for HTTP schedulers.
The master currently has no install handler for {{ExecutorToFramework}} messages and the slave directly sends these messages to the scheduler driver, bypassing the master entirely. We need to preserve this behavior for the driver, but HTTP schedulers will not have a libprocess 'pid'. We'll have to ensure that the {{RunTaskMessage}} and {{UpdateFrameworkMessage}} have an optional pid. For now the master will continue to set the pid, but 0.24.0 slaves will know to send messages through the master when the 'pid' is not available.
Story points: 5