On Wednesday, everything worked as it should, the site was loaded in 3 seconds, it now takes between 15-20 seconds and very often there is a 504 problem. I'm wondering what the problem is because you've completed server maintenance? Whether the problem is to the site, but I did not change anything significantly from the Wednesday, I added one page and that's it. Yesterday and today just throws out 504 error especially when I want to log in to the control panel.
After logging in, I get out the error on the home page of the control panel related to the database. If you can help me with this because I really do not know anything about the databases