When result_workers > 1, race condition exists causing threads to be not labeled properly for debugging. Example output when result_workers=4:
[2016-05-26 12:04:59][17802][TRACE] worker 3 started
[2016-05-26 12:04:59][17802][TRACE] worker 3 started
[2016-05-26 12:04:59][17802][TRACE] worker 4 started
[2016-05-26 12:04:59][17802][TRACE] worker 4 started
When result_workers > 1, race condition exists causing threads to be not labeled properly for debugging. Example output when result_workers=4:
[2016-05-26 12:04:59][17802][TRACE] worker 3 started [2016-05-26 12:04:59][17802][TRACE] worker 3 started [2016-05-26 12:04:59][17802][TRACE] worker 4 started [2016-05-26 12:04:59][17802][TRACE] worker 4 started