My website was pointing to a shared hosting server in Godaddy, it is managed by cPanel. Recently I bought a Godaddy managed VPS. After I had WHM/cPanel installed on it I moved my website to this VPS. What I did was:
1) create a new cPanel account associated with a temporary subdomain(temp.mystie.com) in the new VPS
2) After I transfer files and databases over from the old hosting, I test it and make sure temp.mysite.com is good for visit.
3) I then change the A record of mystie.com to the IP of the new VPS.
4) Then I add mysite.com as an alias of temp.mysite.com in the new cPanel (yes I am lazy)
5) Then I go to the old cPanel and remove mysite.com from it (it was listed as an addon domain)
Now after all this, some of my clients complain that when they try to open the site, they got an error saying the IP of mysite.com can't be found while I myself have no problem opening up the website. I believe if they open it in incognito mode there should be no problem. Please be noted this happened 24 hours after I changed the DNS and I can't tell all of my clients to use incognito mode.
So I'm wondering if I can do anything to prevent this from happening, and I need to learn more about this cache thing. Apparently not only files like .js .css .jpg are cached, but also some other information is also being cached, like DNS information and, seemingly to me in other cases, PHP execution mode. So what kinds of information are being cached exactly? And on my end, can I do anything to prevent my client to get an error when they try to open my website as usual after I recently did some major change to my website?