2.8.15. Session store handler

Storing sessions in Memcache(d) or Redis can speed up the site to some extent due to the fact that the data will not be stored on disk, but in RAM, where the data access speed is higher.

The session.save_handler parameter is responsible for the session storage handler. It defines the name of the handler that is used to store and retrieve data associated with the session.

Change

  1. Open the "PHP settings" section.
  2. In the "session.save_handler" field, select the desired handler and save the changes:
    • "Store sessions in files" — sessions will be stored in files in the standard system directory (default value).
    • "Store sessions in Memcache" — sessions will be stored in cache in RAM (available if you have ordered extra service Memcache(d) or on business hosting plans).
    • "Storing sessions in Redis" — sessions will be stored in cache in RAM (available if you have ordered extra service Redis or on business hosting plans).
  3. Wait 10-15 minutes for the changes to take effect.

Possible problems

When storing sessions in Memcache or Redis, the site code should not contain the commands session_save_path('/tmp') and ini_set('session.save_path', '/tmp') that override the session storage path, or they should contain path to socket from the page of the corresponding extra service instead of /tmp.

If the session storage path is not specified correctly, the site will have these errors:

  • In older versions of PHP:
    PHP Fatal error: session_start() [function.session-start]: Failed to initialize storage module: memcache (path: /tmp)
  • In newer versions of PHP:
    Warning: session_start(): Failed to write session lock: CONNECTION FAILURE
Warning: session_start(): Failed to write session lock: SERVER HAS FAILED AND IS DISABLED UNTIL TIMED RETRY
Warning: session_start(): Unable to clear session lock record
Warning: session_start(): Failed to read session data: memcached (path: /tmp)
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