The problem is that after a apache2 graceful the apc won't work correctly. There is an error message in the apache error.log with "cannot redeclare class bughandlerabstract.
Normaly there is a class with this name, but the correct name ist BugHandlerAbstract.
After a apache2 restart it will work again.
I've tried some changes in the apc.ini, but nothing work right now. I tried also to exclude the BugHandlerAbstract.php from apc with apc.filters, but the problem was not solved.
Then i've done a Zend_Session::writeClose(); in our shutdown handler but also not solving the problem.
Here are the settings of the apc:
apc.cache_by_default 1
apc.canonicalize 1
apc.coredump_unmap 0
apc.enable_cli 0
apc.enabled 1
apc.file_md5 0
apc.file_update_protection 2
apc.filters BugHandlerAbstract.php
apc.gc_ttl 3600
apc.include_once_override 0
apc.lazy_classes 0
apc.lazy_functions 0
apc.max_file_size 1M
apc.mmap_file_mask
apc.num_files_hint 1000
apc.preload_path
apc.report_autofilter 0
apc.rfc1867 0
apc.rfc1867_freq 0
apc.rfc1867_name APC_UPLOAD_PROGRESS
apc.rfc1867_prefix upload_
apc.rfc1867_ttl 3600
apc.serializer default
apc.shm_segments 1
apc.shm_size 768M
apc.slam_defense 1
apc.stat 1
apc.stat_ctime 0
apc.ttl 0
apc.use_request_time 1
apc.user_entries_hint 4096
apc.user_ttl 0
apc.write_lock 1
General Cache Information
APC Version 3.1.7
PHP Version 5.3.3-7
APC Host app6.xxxxxxxxxxxx.de
Server Software Apache/2.2.16 (Debian)
Shared Memory 1 Segment(s) with 768.0 MBytes
(mmap memory, pthread mutex Locks locking)
Start Time 2011/05/20 11:18:48
Uptime 34 minutes
File Upload Support 1
Thanks
I had the same problem in my development box and to be honest I wasn't able to fix it with any proposed solution .
APC is very good but i guess there is no solution to this issue .
I guess its bug in APC so I would advise you to convert your cache host app6.xxxxxxxxxxxx.de to xcache and you would be able to convert to it easily in less than 1 hour , so save your time .