As a starting point I suggest you look at the WebSphere Application Server logging options. User logins and page requests are handled by WAS.

WebSphere logs don't bring much to the party in my experience and WebSphere suffers from not logging any ID in the NCSA Http Logs ( even with http server in front ).   There are audit facilities in WebSphere which might be useful to determine authentication.  A line might look like:

Seq = 923191 | Event Type = SECURITY_AUTHN | Outcome = SUCCESSFUL | OutcomeReason = SUCCESS | OutcomeReasonCode = 5 | SessionId =
 null | RemoteHost = ccm_server | RemoteAddr = 1.2.3.4 | RemotePort = 57081 | ProgName = null | Action = formlogin |
AppUserName = ccm_userid | ResourceName = POST | RegistryUserName = ccm_userid | AccessDecision = authnSuccess |
ResourceType = web | ResourceUniqueId = 0 | PermissionsChecked = null | PermissionsGranted = null |
RolesChecked = null | RolesGranted = null | CreationTime = Fri Aug 26 09:42:42 EDT 2016 | GlobalInstanceId = 0 |
 EventTrailId = null | FirstCaller= tdscalm | Realm = default | RegistryType = LDAP | AuthnType = challengeResponse |
Provider = WebSphere  | ProviderStatus = providerSuccess

Tomcat, when configured with an Access Valve would emit the user ID as part of the log entry.

I've written scripts to collect license information from each of our JTS and collect trends.  This uses repotools-jts -listIssuedFloatingLicenses, which would be useless of your JTS has static licenses.

There are also user feeds that can be collected.   These would be the same information as seen in RTC Eclipse, right click a given user and choose "Show Recent Events", but those are recorded when user makes changes, not when viewing work items, etc.