Why MPM ITK recommended?

[vision1234]

Hi!

We operate with Cloudlinux 7.2 and configuring EA4. We often work with Shopware, which is a onlineshop software from Germany. So I read their performance guide:

To do this, Apache uses one of several existing Multi-Processing Modules (MPMs), a module responsible for deciding how each concurrent request is handled. While several different MPMs exist, Prefork and Worker are the most commonly used. While usually considered faster, Worker is also not thread safe, meaning it does not meet the requirements to execute Shopware. As such, you need to use Prefork to run Shopware.

In other words, in EA I can choose between MPM Prefork and MPM Prefork + MPM ITK (module) as described in cPanel documentation:

EasyApache selects the MPM Prefork by default. Unless you have the CloudLinux™ operating system, we recommend that you use this MPM for stability

If you use the CloudLinux operating system, we recommend that you select the MPM ITK option in EasyApache.

Now I just have a few questions:

1) Why do you recommend to use MPM ITK when using Cloudlinux? Because in all benchmarks I found, it's much slower than MPM prefork. What is the technical reason? (not for being slower; for choosing MPM ITK)

2) I already enabled CageFS. As I read a big plus of MPM ITK is the separating of the vhosts directly in Apache, while CageFS creates a virtualized file system and cages scripts done by apache. But is it necessary to use both techniques? How do they work together?

3) Choosing MPM ITK, in cPanel CGI (not FastCGI) is the only available handler, right?

4) Cause I'm using CGI instead of suPHP it's fully compatible to OPCache and APC, right?

Thanks in advance!

 

[cPanelMichael]

Hello,

1) Why do you recommend to use MPM ITK when using Cloudlinux? Because in all benchmarks I found, it's much slower than MPM prefork. What is the technical reason? (not for being slower; for choosing MPM ITK)

The document you have referenced is now updated for EasyApache 4, and no longer includes that recommendation:

Multi-Processing Modules - MPMs - EasyApache 4 - cPanel Documentation

2) I already enabled CageFS. As I read a big plus of MPM ITK is the separating of the vhosts directly in Apache, while CageFS creates a virtualized file system and cages scripts done by apache. But is it necessary to use both techniques? How do they work together?

You shouldn't have to use both options, but the two are compatible based on the information at:

CloudLinux Documentation

3) Choosing MPM ITK, in cPanel CGI (not FastCGI) is the only available handler, right?

Yes, that is correct. This is documented at:

Apache Module: MPM ITK - EasyApache 4 - cPanel Documentation

4) Cause I'm using CGI instead of suPHP it's fully compatible to OPCache and APC, right?

Opcode caching programs are not compatible with the suPHP or CGI PHP handlers. The caching program either does not function, or functions incorrectly. This is documented at:

PHP Options - EasyApache 4 - cPanel Documentation

Thank you.