Created by: TomorrowIsAnOtherDay
This PR:
- solves the compatibility issue in MacOS/python 2.7.
- fixes a bug that will hang the worker. This bug will happen when the worker creates a large number of jobs at the same time.
- alleviates the issue of too much request of CPU at the master. Now the client instead the actor will sleep 1s and try to submit the job again, when there is no available CPU resource in the cluster.
- prevent the Python library
Popen
from printing warning logs in Python 3.6+.