The MEMCACHED_SERVER_TTL value, in seconds, is the duration for which the cached information is valid (or retained) in Memcached before it is invalidated or removed from Memcached. Enter the TTL (time to live) duration, in seconds, for the MEMCACHED_SERVER_TTL token if and only if you have set the ENABLE_CACHING_WITH_MEMCACHED token to true.
Time duration, in seconds.
600 (seconds)
Updates to TeamForge authorization rules such as PBPs, roles and role assignments, user restrictions, enabling or disabling users and so on can take up to N seconds to take effect, where MEMCACHED_SERVER_TTL=N (seconds). In other words, the mod_authnz_ctf module uses the cached information available with Memcached irrespective of the most recent changes, if any, on the TeamForge side. This implies that having a long TTL duration, while improves the response time, can also result in cached information being out of sync with TeamForge, especially on large sites that are prone to frequent RBAC changes.
See Install Memcached for more information.