[04-Aug-2013 12:28:17] WARNING: [pool admin] server reached 
max_children setting (4), consider raising it

This error happens when the maximum number of PHP processes has been reached. The maximum number of PHP processes that can be run on an instance depends on the size of the pack that you have chosen.

Here are the details for each pack:

• S: 2
• M: 4
• L: 8
• XL: 16
• XXL: 32

If you encounter this error frequently, then we recommend that you upgrade to a higher pack that will be able to handle more PHP processes.