Hi Team
We have recently migrated Business Central to Cloud. It has two Web server in Backend.
1.We started with ALB for Load Balancer, However the First Problem we encountered was Authentication which was going on Loop and Client was presented with constantly being asked to re-authenticate(Reason being When a connection is made NTLM denies the connection and asks it to authentication), Which took us to Layer 4 “network” load-balancers Since Windows Authentication over the Layer 7 “application” load balancer is not possible.
2. After moving to NLB, Authentication Problem Resolved, However after sometime we encountered the session timeout started popping up intermittently while browsing the application.
"Sorry Your Session expired, Please refresh the page to continue"
3. Finally we moved to ELB , Which resolved both issues (Authentication & Session), At least so far we haven't heard any session timeout.
If anyone has encountered such issues. Please let me know what was the fix.
Also we looked at 3 things:
- "Active Sessions" table in database
- UAT Web server 1 IIS logs
- UAT Web server 2 IIS logs
We also discovered the following:Sequence of events:
- My session was established via Web server 1.
- My calls went through web server 1 for about 2 minutes and 40 seconds of operations/navigation.
- After that, my calls suddenly switched over to web server 2.... and at that point, the session expiry message appeared!
Regards
Partha Patnaik
