It is a bit misused term error if "maxclients REACHED server setting, consider raising the maxclients setting. "Is more a Notification Server administrator is warned limit exceeded" maxclients. "It is true that exceeding this limit leads to instability server Apache operating problems and automatically web sites hosted on the server.
Maxclients this Directive Apache that sets limit the number of requestsSites that can be served simultaneously. All queries (requests) that will be made over this limit will be put on hold until a total value established by Directive ListenBacklog. If servers using prefork, Maxclients translates into the maximum number of processes launched to serve requests sites. S default limit of concurrent request set by the 'maxclients "is 150 . If we increase this limit, we must also consider increasing the value of the directive ServerLimit (Sets the maximum value for the life processes Apache). ServerLimit default is set to 256 . Increase value maxclients must be directly proportional to ServerLimit.
However, increasing attention because these two limits far beyond the default setting may prevent start Apache server and operating system instability. The higher the value ServerLimit is higher, the more additional memory (shared memory) will be assigned.
If you encounter error "[Error] server REACHED maxclients setting, consider raising the maxclients setting"(Visible in Apache Error Log) And you decide to change the values that we talked about above, you can do this in two ways.
1. Using the WHM you can change the values of Main >> Service Configuration >> Apache Configuration >> Global Configuration (Applies to servers that have installed cPanel / WHM)
After you change the values in httpd.conf, restart apache server. (service httpd restart).
Stealth Settings - Fix Apache Error: server setting REACHED maxclients.