If you are not familiar with SSO and LTPA, check out our getting started article.
By default, the LTPA timeout is 120 minutes. If you change the timeout, the cell (dmgr, nodes, application servers) will need to be restarted for this change to take effect.
When the LTPA token expires, the following event will be found in the SystemOut.log.
SECJ0371W: Validation of the LTPA token failed because the token expired with the following info: Token expiration: Sun Nov 11 06:51:00 CST 2018 current Date: Sun Nov 11 20:12:40 CST 2019 Token attributes: username=user:defaultRealm/uid=root,o=defaultWIFFileBasedRealm