MinSpareServers and MaxSpareServers – Each virtual server on Apache uses its own set of child processes. With these settings, you can control how many spare processes Apache will run while waiting for more requests. When a child process reaches its maximum requests, the spare processes will be used. On a server with more than 2GB of RAM, you can use a higher number of spare servers to increase speed. If you do not have much RAM to spare, setting the max too high can cause problems.
MaxRequestsPerChild – This is the maximum number of requests a child process will receive before it is killed. Make sure this setting is not too low, or it will create unnecessary load on Apache when it restarts the child.
MaxRequestsPerChild 1000 (for 1GB of RAM, 10,000 for 2GB)
KeepAlive and MaxKeepAliveRequests – This determines how long TCP connections are kept open for requests. Setting this higher will speed up HTML and Image downloading, but it can also add stress to the server. Whether or not to use KeepAlive depends on the purpose of your server. For a hosting server with shared hosting accounts, KeepAlive will probably just add too much CPU intensive stress. For a server with a single site that serves a lot of documents and demands speed (something like a wiki), you might want to keep it on.
KeepAlive off (or on – your choice)