Magento + APCu caching issue. Site is slow and there is more cache misses than hits

By | January 12, 2018

I have a Magento installation running on LEMP Stack; Nginx + PHP-FPM (PHP v5.5.6 w/ APCu v4.0.2) + Percona.

I’ve configured my magento to use APCu caching like this:



and the APC is configured like this:


apc.enabled          = 1
apc.shm_segments     = 1
apc.shm_size         = 512M
apc.ttl              = 7200
apc.user_ttl         = 7200
apc.num_files_hint   = 10240
apc.mmap_file_mask   = /tmp/apc.XXXXXXX
apc.enable_cli       = 1
apc.cache_by_default = 1
apc.max_file_size    = 10M
apc.stat             = 1

and here’s the apc info page displaying the huge miss to hit ratio:

enter image description here

Any idea what might be wrong?


We had the same problem. After days of changing things it was a simple solution.

In the local.xml file you have used


for some reason Magento & APCu will only accept alphanumeric characters in the prefix so we found that dropping the underscore “_” solved our problems


APC settings seems to be fine. You can do next:

1) Clear var/cache in Magento web root folder.

2) Check, do you have enabled eAccelerator? If yes – disable it.

Btw, APC is not a good tool for Magento caching because Magento use built-in Zend-based cache.

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