On shared hosting, many websites share one server. Each site is monitored so that one busy site can't slow down the others. The limits cover:
- simultaneous connections to the web server;
- CPU use, as a share of what the server sets aside for websites;
- memory use, on the same basis;
- simultaneous processes;
- simultaneous database connections;
- database queries per hour.
If your site reaches them
A site that regularly hits these limits slows down, and heavy scripts may be stopped. Common causes, in order of likelihood:
- A plugin or script running a slow query on every page — a caching plugin often fixes it.
- Automated traffic: bots, scrapers, or an attack on the login page.
- Genuine growth.
For genuine growth, the site needs resources of its own. Cloud hosting grows without moving; a VPS or dedicated server gives you a machine — or a slice of one — for your site alone.
Tip
Not sure which it is? Open a ticket naming the site. We can see which limit is being hit and tell you what's using it.