Magento front-end session timing out too soon

Problem:Magento site is timing out faster for users than your current “Cookie Lifetime” setting (default is 3600 seconds), PHP’s session.gc_maxlifetime parameter may be the problem.

Firstly, check your “Cookie Lifetime” setting to ensure it is set correctly by logging in to the Magento Admin Panel and navigating to System → Configuration and clicking “Web” under “GENERAL” in the left side menu. Look under “Session Cookie Management” for “Cookie Lifetime” and make sure that it is set as intended (in seconds).

Assuming that this was not the issue, open your sites php.ini file and look for “session.gc_maxlifetime”. If this is set to a smaller total number of seconds than your Magento “Cookie Lifetime” setting, PHP will clear the session data before Magento has the chance.

To fix this simply set “session.gc_maxlifetime” to a number greater than or equal to “Cookie Lifetime” and save your php.ini file.