What would be the most efficient way to push updates to an Apache server without shutting down?

What would be the most efficient way to push updates to an Apache server without "shutdown" (a.k.a. redi开发者_开发百科recting everyone to a maintenance page) in a simple LAMP server.

One of the idea I had is to use a .htaccess that redirects all requests to a single PHP script that just wait until they can response the requests but all connexions will remain active for that time. I don't know how much consecutive connection that server could handle.

Any tips?

Thank you

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If you really need to do that without downtime - create high available schema with at least 2 replicas of every resource you have (webserver, db server, etc).

So when you need to update all - just detach one webserber and one database server from your load balancer and update them. After you have done that - attach them back and repeat the same steps with the servers that haven't been updated yet.