On our new CentOS 7 VPS, we have noticed that the RSS memory usage of httpd processes are quite high as compared to our other CentOS 6 VPS. On average, the memory used by httpd on CentOS 7 is almost 3-4 times the httpd memory usage on CentOS 6. Both the VPS currently have around 12-15 cPanel accounts each. In terms of website load, both the systems have fairly identical traffic.
How do I find out what is triggering the higher httpd memory usage on CentOS 7?
High Apache memory usage on CentOS 7
Re: High Apache memory usage on CentOS 7
First explanation is of course that the Apache versions of CentOS 6 and 7 differ.
When you get a VPS, it usually comes with a configuration that has been trimmed to the amount of resources (memory, CPU, disk space) that the VPS has. It is likely that at the time you got the CentOS-6 VPS it came was less memory than your CentOS-7 VPS had when you got that. So the Apache setups may have been trimmed differently.
There are many factors that may effect the memory footprint of Apache. To name a few:
- Number of modules loaded.
- Number of worker threads started.
- Are scripts executed within an Apache module or by external processes.
- Pre-allocation of resources.
When you get a VPS, it usually comes with a configuration that has been trimmed to the amount of resources (memory, CPU, disk space) that the VPS has. It is likely that at the time you got the CentOS-6 VPS it came was less memory than your CentOS-7 VPS had when you got that. So the Apache setups may have been trimmed differently.
There are many factors that may effect the memory footprint of Apache. To name a few:
- Number of modules loaded.
- Number of worker threads started.
- Are scripts executed within an Apache module or by external processes.
- Pre-allocation of resources.
Re: High Apache memory usage on CentOS 7
memory is to be used, if your system is swapping then you take care