If you have not already done so, in the Change Center of the Administration Console, click Lock & Edit (see Use the Change Center).
Expand
Compatibility Security > Caching
Realms and click the name of the Caching realm.
Expand
Configuration >
Authentication and check Enable
Authentication Cache.
Set the size and duration attributes for the Authentication
cache.
Click
Save to save your changes.
To activate these changes, in the Change Center of the Administration Console, click Activate Changes. Not all changes take effect immediately—some require a restart (see Use the Change Center).