Secure Store Service application is not accessible

Question

I have a SharePoint 2016 farm running on 4 Windows 2016 servers (1 web, 1 app, 1 Office Server, 1 SQL).

Approximately once a week, we are experiencing an outage that requires an IIS Reset to resolve. Checking the event logs, it appears that the secure store service is failing. I get a lot of 7557 errors in the application event log:

The Secure Store Service application Secure Store Service is not accessible. The full exception text is: The HTTP service located at http://localhost:32843/SecurityTokenServiceApplication/securitytoken.svc/actas is unavailable

I also see a lot of 8306 events:

An exception occurred when trying to issue security token: An error occurred while receiving the HTTP response to http://localhost:32843/SecurityTokenServiceApplication/securitytoken.svc

After the IIS Reset, the token service url works fine. I'm trying to find the root cause of these errors. I've had a look in the HTTPERR logs. There are a lot of Connection_Dropped and Connection_Dropped_List_full errors around the same time as the outages. However, I don't know where to go from here.

Any suggestions?

Answer 1

It may have something to do with the unloading forcibly profiles. I have mainly seen it on the FBA sites. and IIS reset has resolved for me as well. If your case is the same you need to:

You need to change the GP policy: Computer Configuration->Policies ->Administrative Templates->System-> User Profiles 'Do not forcefully unload the user registry at user logoff'

REF: https://social.technet.microsoft.com/Forums/en-US/88b75db9-3046-4d7c-8e30-5f2ec31e86ff/drawbacks-of-enabling-do-not-forcefully-unload-the-user-registry-at-user-logoff-in-group-policy?forum=winserverGP

After applying this you will receive those errors:

Windows cannot unload your registry file. The memory used by the registry has not been freed. This problem is often caused by services running as a user account. Try configuring services to run in either the LocalService or NetworkService account

But at least things are working as expected.