Why is traffic unbalanced after adding a third host to HAPROXY?

Question

HAproxy

Hello everyone,
added a third web host to HAProxy Load balancer configured for leastconn. Although some of the connections go to the third host, there are very few of them... 3-5%
The site with the balancer is used by our client, where they go from the internal network, so it's possible that the cookies remain old. How to check it? Could this be causing so few sessions to go to host No 3? All IP addresses are external, including the balancer and hosts.
good luck,
Vadim

Answer 1

maybe the cookies are old. How to check it?

I would try temporarily excluding the old servers - one at a time.