There are a few known issues which can crop up on XNAT installations when users log in. Most of these are rare, and some can be addressed or mitigated by updating to the latest XNAT release.
Problem: Login process is very slow, or times out
JIRA Issue XNAT-5528 - Login Page is slow to load on XNATs with many users and guest account enabled
JIRA Issue XNAT-4798 - Login process can be very slow for non-admin users who have permissions on hundreds of projects
XNAT 22.214.171.124 addressed a severe performance issue related to logging in that affected "super-users" who did not have Admin access, but who have any kind of access to hundreds of projects. This is a rare situation, but for these users the login process could take minutes, prior to upgrading. If you see issues like this on the latest version of XNAT, please report them.
Problem: User does not appear to have access to data types or projects that were recently updated
JIRA Issue XNAT-5804 - Allow user to clear their own data type cache
New in XNAT 126.96.36.199, performance of page loads and data listing display have been improved overall by caching data type listings on Tomcat startup. This cache should be updated for all users whenever a new data type is installed, or project permissions are changed. However, if a user logs in and it appears that this user does not have access to data that they should, it may be that the user needs to refresh this user cache. After the user logs in, follow these steps:
- Click on your user name in the right side of the top toolbar
- On the "Manage User Login and Profile" page, click on the "Manage Cached Resources" tab
- Click the "Reset Access Cache" button
The user may need to log out and log back in to see project access changes. Data type listings should come back right away.