Recommended session extension timeout - Liferay

portal-session-ext.properties

#
# Specify the number of minutes before a session expires. This value is
# always overridden by the value set in web.xml. NOTE: the <session-timeout>
# attribute in the web.xml files overrides these values. Comment them out. 
#
session.timeout=5

#
# Set the auto-extend mode to true to avoid having to ask the user whether
# to extend the session or not. Instead, it will be automatically extended.
# The purpose of this mode is to keep the session open as long as the user's
# browser is open with a portal page loaded. It is recommended to use
# this setting along with a smaller "session.timeout", such as 5 minutes,
# for better performance.
#
session.timeout.auto.extend=true