the mongodb-consistent-backup is blocked

[yangzan66]

why the mongodb-consistent-backup is blocked in "Stopping the balancer and waiting a max of 300 sec" and cann't continue? the log as follows:

[2019-10-07 09:39:02,790] [INFO] [MainProcess] [Main:run:299] Running backup in sharding mode using seed node(s): 172.20.0.87:27017
[2019-10-07 09:39:02,793] [INFO] [MainProcess] [Sharding:get_start_state:68] Began with balancer state running: True
[2019-10-07 09:39:02,916] [INFO] [MainProcess] [Sharding:get_config_server:189] Found sharding config server: configRS/IDCV-Mongo1:27019,IDCV-Mongo2:27019,IDCV-Mongo3:27019
[2019-10-07 09:39:02,951] [INFO] [MainProcess] [Sharding:stop_balancer:150] Stopping the balancer and waiting a max of 300 sec