Add retry limit when get trainer job errors, improve error logging.
Add retry limit when get trainer job errors, improve error logging.

gongweibao/cloud,PaddlePaddle/cloud,PaddlePaddle/cloud,gongweibao/cloud,gongweibao/cloud,PaddlePaddle/cloud,gongweibao/cloud,gongweibao/cloud,PaddlePaddle/cloud,PaddlePaddle/cloud