Since we moved to PHP 5.5 and it’s built in zend opcache, we decided to stop using APC.

Since zend opcache filled opcaching need only, we needed something for data-cache. There is one APC fork trying to extract data-caching code on Github. But we wanted something stable and mature so we choose to go with memcache.

I always hated presence of php5-memcache and php5-memcached – two solutions for similar needs. I read this and this and many more threads but could reach a conclusion.

Actually for our trivial needs both extensions should work fine. But we (forced) to choose php5-memcache as w3-total-cache doesn’t support only this!


apt-get install memcached php5-memcache
service php5-fpm restart


Increase Max Memory memcache can use

By default, its 64MB. You may need more.

  1. Open /etc/memcached.conf 
  2. Look for value -m 64
  3. Change it to -m 1024
  4. Restart memcached  service memcached restart

Move PHP’s session storage to memcache

Open /etc/php5/mods-available/memcache.ini

Add following lines:

session.save_handler = memcache
session.save_path = "tcp://localhost:11211"

Extra: Since memcached can works in multiserver mode, you can share session across server. Google for more info on this. I will post our config when we will write one! 😉

Changes in w3-total-cache plugin

In w3-total-cache plugin you need to choose memcache as backend for object-cache and database-cache.

Web-based Stats Viewer for Memcache

There are many but we choose phpmemcacheadmin

cd /var/www/
mkdir mem && cd mem
tar -xvzf phpMemcachedAdmin-1.2.2-r262.tar.gz
chmod +r *
chmod 0777 Config/Memcache.php


16 responses to “memcache”

  1. Hi, as soon as I set session.save_handler = memcache (and restart php5) I get PHP Internal Server Errors all around… I cannot for the life of me figure out why ;(
    Can anyone share some tips on debugging this?

  2. I’m using also php5.5 with the zend optimiser. I’ve got issues each time I save the settings in W3TC. I think the setting page is cached by the zend optimiser (not by nginx) so the only way to see the changes is to force a browser refresh. Weird. Any way to force the zend optimiser to check the cache for each request? (like apc stat 0)

  3. So, i use php 5.3…and want use memcached also
    when i uncomment memcache.ini

    session.save_handler = memcache
    session.save_path = “tcp://”

    my WP not work, blank page
    memcached server is starting of course…and config to -l

    • Yes. It seems redis is faster but did not proper support for redis in wordpress & nginx world. So for now using memcache.

      Also difference is too small to matter for WordPress/content sites.

  4. Just to add that if installing all this you need to do service php5-fpm restart so w3-total cache will recognize the install

  5. Hello!
    When i’m trying connect to memcache-server using connect – all work very good. But when i trying use addServer – I all time see error timeout connect to server.
    Can you help?

  6. Hi, really like your posts about wordpress and nginx setup
    how can I make sure I’m using memcache right?

    I install the phpmemcacheadmin, but all the status is 0 ??


    • Run service memcached status
      You should see: * memcached is running

      Also, make sure you have configured WordPress/W3-Total-Cache plugin to use database-cache/object-cache.