Increasing PHP memory_limit. At what point does it become insane?

Question

In a system I am currently working on, there is one process that loads large amount of data into an array for sorting/aggregating/whatever. I know this process needs optimis

Answer 1

Given that you know that there are memory issues with your script that need fixing and you are only looking for short-term solutions, then I won't address the ways to go about profiling and solving your memory issues. It sounds like you're going to get to that.

So, I would say the main things you have to keep in mind are:

• Total memory load on the system
• OS capabilities

PHP is only one small component of the system. If you allow it to eat up a vast quantity of your RAM, then the other processes will suffer, which could in turn affect the script itself. Notably, if you are pulling a lot of data out of a database, then your DBMS might be require a lot of memory in order to create result sets for your queries. As a quick fix, you might want to identify any queries you are running and free the results as soon as possible to give yourself more memory for a long job run.

In terms of OS capabilities, you should keep in mind that 32-bit systems, which you are likely running on, can only address up to 4GB of RAM without special handling. Often the limit can be much less depending on how it's used. Some Windows chipsets and configurations can actually have less than 3GB available to the system, even with 4GB or more physically installed. You should check to see how much your system can address.

You say that you've increased the memory limit several times, so obviously this job is growing larger and larger in scope. If you're up to 1.5Gb, then even installing 2Gb more RAM sounds like it will just be a short reprieve.

Have others encountered this kind of issue? and what were the solutions?

I think you probably already know that the only real solution is to break down and spend the time to optimize the script soon, or you'll end up with a job that will be too big to run.