I made the decision to set up APC to accelerate the website which i work with. Sadly, I discovered it had been installed and enabled(The developer who first done the servers has managed to move on).

I Quickly made the decision to determine the use of it to ascertain if it requires more memory allotted into it or otherwise. This is where I came across something strange. An easy file with this particular code:

<?php
    print_r(apc_cache_info());
?>

It wouldn't work when offered from apache. I recieve Error 320 (net::ERR_INVALID_RESPONSE): Unknown error. And there's nothing within the error log. In the cli around the server, it really works fine. However it only states that my check_apc.php file is cached(title from the script which i was running).

Therefore it appears like APC hasn't fully/properly been setup. Anyone understand what the issue might be?

Items in /etc/php.d/apc.ini:

; Enable apc extension module
extension = apc.so
; Options for the apc module
apc.enabled=1
apc.shm_segments=1
apc.optimization=0
apc.shm_size=32
apc.ttl=7200
apc.user_ttl=7200
apc.num_files_hint=1024
apc.mmap_file_mask=/tmp/apc.XXXXXX
apc.enable_cli=1
apc.cache_by_default=1

The server is running CentOS

Has anybody upgraded the version of php around the server since apc.so was produced? It might be that apc.so was put together against another version of php.

If at all possible, try re-producing apc.so from the current version of php. Or if you work with a package manager, try getting rid of the apc package entirely and re-install it.