session_gc_maxlifetime

Name: Session Garbage Collector Max Lifetime
Type: String
Default: 604800
Available In: Revolution 2.1.1+

Age in seconds after which modSessionHandler may delete a session row during PHP session garbage collection. Default 604800 is seven days. MODX also applies this value to the PHP session.gc_maxlifetime ini setting when it starts the session.

GC only runs when PHP’s session.gc_probability / session.gc_divisor allow it. On many Debian/Ubuntu hosts probability is 0, so this setting never takes effect until you fix the server or add a cron. See Session Garbage Collection.