所以我试图通过stdout在mongodump上转储一个集合，这样我就可以直接管道并gzip了。但它给了我错误。
当我这样做时：
mongodump --db test -u username -p Password -h mymongodatabase.onthecloud:12888 -vvvvv --collection posts --out -
显示以下错误：
Wed Feb 29 21:48:13 creating new connection to:mymongodatabase.onthecloud:12888
Wed Feb 29 21:48:13 BackgroundJob starting: ConnectBG
Wed Feb 29 21:48:13 connected connection!
connected to: mymongodatabase.onthecloud:12888
Wed Feb 29 21:48:13 nextSafe(): { $err: "unauthorized db:test lock type:-1 client:10.3.55.10", code: 10057 }
Wed Feb 29 21:48:13 User Assertion: 13106:nextSafe(): { $err: "unauthorized db:test lock type:-1 client:10.3.55.10", code: 10057 }
assertion: 13106 nextSafe(): { $err: "unauthorized db:test lock type:-1 client:10.3.55.10", code: 10057 }
但是当我试图包含'--out - '时，它会将收集转移得很好（不会给我一个错误的错误）。发生了什么事？