Absurdly wrong PHP settings (part 1): Memory Limit = -1

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Absurdly wrong PHP settings (part 1): Memory Limit = -1

Post by sozzled » Wed Jun 07, 2023 9:50 pm


The following guide for PHP settings with J! appears below:


What does Memory Limit = -1 mean?

See https://serverfault.com/questions/81706 ... p-ini-file.

The PHP memory limit should be set to a specific number; it should not be left "undefined" or set to a ridiculously large value (e.g. greater than 4Gb).

If the memory limit is undefined then J! will encounter problems (particularly when running the Joomla! Update component).

What is the value of the PHP Memory Limit used by your J! website

There are several ways:
  • Go to System » System Information » PHP Settings and search for "Memory Limit".
  • If you have access to you web host's cPanel (or something similar with a PC-hosted AMP stack like Wampserver) look for PHP settings with the version of PHP you're using.
  • Run the Forum Post Assistant and post the [BBcode] report if you have a question for this forum.

Set or change the value of Memory Limit to a "reasonable" value. As a minimum, I recommend trying 512M as a "reasonable" value. For the reliable operation of a J! 4.x website, do not use a value less than 256M (there's no good reason to be a miser here); while it normally doesn't cost anything to increase the memory limit over 512M, don't go "overboard" and set a ridiculously high value (e.g. greater than 4096M).

Setting a "reasonable" value for Memory Limit may require some trial and error. There is no one-size-fits-all solution so you have to be patient and experiment. The value of Memory Limit depends on the number of concurrent user sessions you have running, what third-party extensions you have installed, the effective performance of the machine that is hosting your website, and whether the memory allocated by PHP to your website is dedicated to the site or whether the value is pooled (i.e. shared between other websites on the server).

Known problems

An "undefined" memory limit (i.e. Memory Limit = -1) is known to cause problems with Joomla. If it did not cause problems I would not have written this post on the forum. My advice is to check the PHP setting for Memory Limit and set it, or change it, to a specific value. If more people carried out this simple check then we would probably see fewer questions about the same kinds of problems that we often see. 8)

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