为什么群不清洗旧的容器

在docker swarm update --image newImg容器更新图像之后docker swarm update --image newImg我已经检查了容器列表docker swarm update --image newImg docker ps -a ，看到许多容器仍然存在，但停止

 4d4753bbbc68 serviceA@sha256:81333c059f81340dcfad01ad4f09498956cdc9eadc0552f22b8b323554ec2ced "service.py" 9 minutes ago Up 9 minutes serviceA.5.pya3ka5j1hfrt8h3ip47alx6k bc777058b504 serviceA@sha256:81333c059f81340dcfad01ad4f09498956cdc9eadc0552f22b8b323554ec2ced "service.py" 9 minutes ago Up 9 minutes serviceA.1.k59s3dd3r7h7yf5so035ddr87 7fdfcbd0251e serviceA@sha256:81333c059f81340dcfad01ad4f09498956cdc9eadc0552f22b8b323554ec2ced "service.py" 9 minutes ago Up 9 minutes serviceA.3.w8dsvjjkw5bwolka9s7pa7j4g b50ac059d801 serviceA@sha256:81333c059f81340dcfad01ad4f09498956cdc9eadc0552f22b8b323554ec2ced "service.py" 10 minutes ago Up 9 minutes serviceA.2.223vk9hrd0ozjwpmdv0uk16fp f9dfb2478cf8 serviceA@sha256:81333c059f81340dcfad01ad4f09498956cdc9eadc0552f22b8b323554ec2ced "service.py" 10 minutes ago Up 10 minutes serviceA.4.27lgp5wakt1m9as1l8g4ypdxu 27ff904c13a3 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 12 minutes ago Exited (137) 9 minutes ago serviceA.1.sd3gh12r5y33gpqualv787u8n aff08c144eea serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 12 minutes ago Exited (137) 9 minutes ago serviceA.2.koede0ww0nqz3mowiltomtl1v 2fb7b54255c1 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 12 minutes ago Exited (137) 10 minutes ago serviceA.4.hpatzok3cbaiz3vea6jl8rt31 77746f0fd9a1 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 13 minutes ago Exited (137) 9 minutes ago serviceA.5.usucdxxobjlozpqqb7qmfhcyj 1e42aea4d1b1 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 13 minutes ago Exited (137) 9 minutes ago serviceA.3.pi6ueashgsqncusgcmn651pl5 83ea51930352 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 8 days ago Exited (137) 12 minutes ago serviceA.5.7f9kl4vkp94nkfadsdk27ryb2 4cf61a758cbf serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 8 days ago Exited (137) 12 minutes ago serviceA.4.iplu7tjyhp3o52ksy6azft6ze 854a4805766c serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 8 days ago Exited (137) 12 minutes ago serviceA.2.ntcw5rgoce21n60rds5ncnflq 6ca327779108 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 8 days ago Exited (137) 12 minutes ago serviceA.1.yvv1o5fvnlugqd3e9f7hhj8em 298794d86090 serviceA@sha256:fb7a8f65d5f53fc18a101945d21cfe4cc94c8cb2ac4d5fdb43053c492b2e2b22 "service.py" 8 days ago Exited (137) 13 minutes ago serviceA.3.zkyegkinmd2q5lr3q3k47n5od 

我希望群清理旧的，但没有。
为什么？ 这是一个function吗？ 似乎它节省了一些快速回滚的集合，但自1.31 API版本，我不知道。

我必须自己清理过时的容器吗？