Memcache: /usr/sbin/httpd: symbol lookup error: /usr/lib64/php/modules/memcached.so: undefined symbol: memcached_last_error_errno

Question

I'm getting the above error as soon as I enable Memcache at my Drupal application.

• Memcache is within the same environment as Apache
• PHP version 5.5.0
• "extension=memcached.so" added to php.ini
• Error doesn't appear on local dev environment
• Error doesn't appear on another VPS

This issue may be related to an outdated libmemcached version: https://serverfault.com/questions/456300/upgraded-php-to-5-3-19-and-memcached-stopped-working

Is there anything I can try?

Answer 1

As you can see from the attached picture, extension has a name memcache.so (also, there are several additional extension versions in the modules folder), so it is necessary to specify in the php.ini correct file name. Please, change the name and try if it works.