APC - "503 Service Unavailable"

Discussion in 'Install/Configuration' started by MikeDVB, Jan 14, 2011.

  1. MikeDVB

    MikeDVB Well-Known Member

    Upon rebuilding PHP 5.2.14 via LSWS's control panel and building in APC support, when enabling apc.so we get 503 errors:
  2. webizen

    webizen Well-Known Member

    Is there anything in stderr.log when this happens? What's your server environment?
  3. MikeDVB

    MikeDVB Well-Known Member

    I didn't check the stderr.log, but I can watch it when I enable apc to see if anything hits it.

    Beyond that, it's a CentOS 5 OpenVZ VPS.
  4. skippybosco

    skippybosco Member


    In reading through the forums here I tested updating the php.ini with:
    apc.enabled = 1
    apc.shm_size = 48
    apc.include_once_override = 1
    apc.mmap_file_mask = /tmp/apc.XXXXXX
    This made things a little better in that it is not consistently throwing 503 , but still seeing them >30% of the time so I ended up having to disable the APC extension.

    Aside from the server states Michael provided above, the website itself is a Wordpress 3.0.4 installation running WP Super Cache.

    PHPINFO() suggests the APC bundled with LITESPEED is the beta version (3.1.4). Other threads in this forum suggest that was the root of their 503 errors and reverted to 3.0.9 stable.

    That being said, looks like 3.1.6 is the the latest STABLE of APC.

    Regarding stderr.log the consistent errors being thrown are:

  5. skippybosco

    skippybosco Member

    After a bit of research (and much effort by Mike) we may have this sorted out.

    Even after using 3.019 of APC we were still seeing issues, turns out a conflict with ZEND was the culprit in this case. Once the ZEND extension was disabled everything has been running pretty smooth.

    I'll monitor over over the next couple of days to ensure it is stable.. After which we can revisit if we should a) Move to LITESPEED bundled 3.14 beta b) Move to 3.16 STABLE c) Be thankful and leave well enough alone :)

  6. csdco

    csdco Member

    Thanks for posting your info. Please post back if you have any updates. We need Zend & APC, so disabling APC may be the only route we can take :(
  7. skippybosco

    skippybosco Member

    Disabling APC did not work for us, it was necessary to disable Zend. APC is working without issue for us.


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