I am using HAProxy (Community Edition) for a Redis Server access (High Availability for a master-slave Redis setup).
It runs on a Debian Stretch (9.9) LXC container installed from the apt repository haproxy.debian.net.
After upgrading from HAProxy 1.9.8-1~bpo9+1 to 2.0.1-1~bpo9+1, I noticed a server connection issue: Server connections on Redis grew up from about 50 connections to 4000, making Redis Server unavailable under peak periods.
After downgrading to 1.9.8-1~bpo9+1, everything was back to its original state (server connections came back to around 50).
Usually, the number of client connections is around 50, but can reach 500 under certain circumstances.
Is there a change between 1.9.x and 2.0.x that could explain this problem?
Here is my HAProxy configuration file (same conf used for v1.9.8 and 2.0.1):
global log /dev/log local0 log /dev/log local1 notice chroot /var/lib/haproxy stats socket /run/haproxy/admin.sock mode 660 level admin stats timeout 30s user haproxy group haproxy daemon maxconn 32000 defaults log global mode http option httplog option dontlognull option dontlog-normal timeout connect 5000 timeout client 50000 timeout server 50000 frontend redis_master bind 10.2.1.100:6379,10.2.1.101:6379 option tcplog mode tcp timeout client 10s default_backend redis_master backend redis_master mode tcp balance first timeout connect 4s timeout server 10s option tcp-check default-server rise 1 on-marked-down shutdown-sessions server 10.2.1.3 10.2.1.3:6379 check #disabled server 10.2.1.4 10.2.1.4:6379 check disabled