Improve scheduler throughput

[junyuanZhang-cb]

Does anyone have idea what is the max throughput of st2scheduler?

With one scheduler, I found the rps is round 7.
And multiple schedulers will lead to collisions:

INFO [-] [628547931e90748fa93e12a7] Item "628547936e7e006b1003f65f" is already handled by another scheduler.

With 5 schedulers, the rps is around 10. Is there any way we can improve the throughput of schedulers?