Knowledge map advanced must read: read how large-scale map data efficient storage and retrieval>>> 
The solution is to edit the domain name profile
$ vim /etc/resolv.conf
Add a domain name resolution server
nameserver 8.8.8.8
Knowledge map advanced must read: read how large-scale map data efficient storage and retrieval>>>
The solution is to edit the domain name profile
$ vim /etc/resolv.conf
Add a domain name resolution server
nameserver 8.8.8.8