Apache: How to increase the maximum client connection?

By default Apache only allows up to 150 connections , if you want more, you need to change the MaxClients parameter in apache.conf or httpd.conf . Apache also limit the max clients to 256 , if you want to override this value, you need to add ServerLimit.

Here is an example to increase the max clients to 600.

# prefork MPM
# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# MaxClients: maximum number of server processes allowed to start
# MaxRequestsPerChild: maximum number of requests a server process serves

    StartServers        5
    MinSpareServers     5
    MaxSpareServers     10
    ServerLimit 600
    MaxClients          600
    MaxRequestsPerChild 0

After you update the configuration file, you must stop the apache and start it again , restart doesn’t apply the change.