Buy Cheap VPS support often receives inquiries about optimizing the Apache service. This article offers simple yet effective ways to optimize Apache based on VPS resources. By default, Apache uses the "prefork" module, where each process handles one request. These processes need to be defined with precise numerical values to prevent Apache from using excessive VPS resources.
To optimize Apache, four main variables are used:
- StartServers: The number of child server processes created at startup.
- MinSpareServers: The minimum number of idle child server processes.
- MaxSpareServers: The maximum number of idle child server processes.
- MaxClients: The maximum number of simultaneous connections Apache will handle.
The optimal values for these variables can be calculated as follows:
- StartServers = RAM / 128
- MinSpareServers = RAM / 256
- MaxSpareServers = RAM / 64
- MaxClients = RAM / 32
Note: RAM refers to the total Random Access Memory of your server.
For example, on a VPS with a 4 GHz CPU, 4 GB of RAM, 50 GB of storage, and 4 TB of bandwidth:
- StartServers = 4096 / 128 = 32
- MinSpareServers = 4096 / 256 = 16
- MaxSpareServers = 4096 / 64 = 64
- MaxClients = 4096 / 32 = 128
To adjust these variables, edit the Apache configuration file by running:
nano /etc/httpd/conf/httpd.conf
Locate the variables mentioned above and update them according to the calculated values. If they are not found, add the following lines at the end of the file:
</IfModule>
KeepAlive Off
<IfModule prefork.c>
StartServers 32
MinSpareServers 16
MaxSpareServers 64
MaxClients 128
</IfModule>
After making the changes, restart the Apache server:
service httpd restart
