unreachable error when add or delete node

[JohanOu]

Organization Name:

Short summary about the issue/question:
when i try to delete a node,i miss the error like the figure.But I can ssh the master in the dev-box container,how to solve?Thanks

Brief what process you are following:

How to reproduce it:

OpenPAI Environment:

• OpenPAI version:v1.8.0
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Hardware (e.g. core number, memory size, storage size, GPU type etc.):
• Others:

Anything else we need to know:

[Binyang2014]

Can you run the script with -vvvv, this flag will print the verbose log which will help to debug