ffff888811282000: VS x.x.x.x:port (9): Connection Failed to x.x.x.x:port (111)
Customer facing issues that every 8am which is peak hours, when many users accessing the application LB through KEMP, they would face login issues.
Meaning users can reach to the login page during peak hours, then they would get server error 404 prompt.
As per checking by the application vendor, it was due to connection closed prematurely between 2 the login page web servers and the backend applications.
Both login page web servers and backend application servers are LB by KEMP.
Whenever this issue happens, customer would either:
1. Disable and Reenable all the RS on KEMP
2. Restart IIS on the RS servers.
Once done either of these steps, the issue would not happen again.
We checked on KEMP that there are no Down RS servers or even System Performance spike on KEMP during the issue happen.
|Steps to Reproduce:|
2023-04-03T08:18:05+08:00 lb100 kernel: L7: ffff888806575290: VS x.x.x.x:port (5): Connection Failed to x.x.x.x:port (111)
Customer configured all health checks to be icmp ping only.
ICMP ping is not good enough to check that the actual service hosted on server is not responding.
|Resolution:||Customer have changed the health check methods from Ping to TCP for customer’s KEMP.|