Limit of concurrent connections! What is considered as "safe"?

Hello, I have a plan with a hosting company and I just discovered that I have a limit on the number of concurrent connections.I will get "503 Service Temporarily Unavailable" error if I ever reach this limit. Therefore I was wondering what is considered as "safe"? I know that this "depends" on the type of website, but I was wondering if there where some good statistics on which I could base my reasoning.

My problem is that I only got to know about this limit now and therefore do not know if I have to worry or not. At the moment my limit is set to 100 concurrent connections.

The concurrent connection limit isn't exactly a safety limit, it exists to prevent the web server from becoming overloaded. What you can set it to depends on how powerful the web server hardware is and how resource intensive loading your web site is. The only way to really properly set it is through trial and error. If your server is hitting the limit and still has plenty of resources left then it can be raised; if your server is bogging down before hitting the limit then it should be lowered.

If the limit is optimized and you're still hitting it, it means you either need a more powerful server or just more servers.