What is your value for php memory_limit. I read on internet "Golden rule, give to php what is he consume not more not less".
We have four web server with 8Go ram for each instance. We have very hight traffic. Actualy we have set the memory_limit to 128 Mo and we plan to raise to 512 Mo.
I think it's to much, few pages consumes memories (export data, import data, upload image....), i'm not sure that increasing the memory for the whole php scripts is in good approach.
I would like to have your views on the issue.