HaProxy has the Loadbalancer for spring boot application - spring-boot

Question

i have configured haproxy as the load balancer for two containerised spring boot application
Below is the sample docker compose file configuration
version: '3.3'
services:
wechat-1:
image: xxxxxx/wechat-social-connector:2.0.0
container_name: wechat-1
ports:
- 81:8000
networks:
- web
#depends_on:
#- wechat-2
wechat-2:
image: xxxxxxxxx/wechat-social-connector:2.0.0
container_name: wechat-2
ports:
- 82:8000
networks:
- web
haproxy:
build: ./haproxy
container_name: haproxy
ports:
- 80:80
networks:
- web
#depends_on:
#- wechat-1
networks:
web:
Docker file
FROM haproxy:2.1.4
COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
HA Configuration file
global
debug
daemon
maxconn 2000
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
frontend http-in
bind *:80
default_backend servers
backend servers
mode http
option httpchk
balance roundrobin
server wechat-1 wechat-1:81 check
server wechat-2 wechat-2:82 check
when i am trying to access my endpoints using the port number 80 i always getting the service unavailable.
After debugging from the haproxy logs noticed the below error
Creating haproxy ... done
Creating wechat-2 ... done
Creating wechat-1 ... done
Attaching to wechat-2, wechat-1, haproxy
haproxy | Available polling systems :
haproxy | epoll : pref=300, test result OK
haproxy | poll : pref=200, test result OK
haproxy | select : pref=150, test result FAILED
haproxy | Total: 3 (2 usable), will use epoll.
haproxy |
haproxy | Available filters :
haproxy | [SPOE] spoe
haproxy | [CACHE] cache
haproxy | [FCGI] fcgi-app
haproxy | [TRACE] trace
haproxy | [COMP] compression
haproxy | Using epoll() as the polling mechanism.
haproxy | [NOTICE] 144/185524 (1) : New worker #1 (8) forked
haproxy | [WARNING] 144/185524 (8) : Server servers/wechat-1 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
haproxy | [WARNING] 144/185525 (8) : Server servers/wechat-2 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 0 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
haproxy | [ALERT] 144/185525 (8) : backend 'servers' has no server available!
from the logs i understand when haproxy is not able to connect the other two containers which are running perfectly with out any issues.
i tired to use the depends_on attribute(commented for time being) still the issue same .
Can some one help me in fixing this issue?

Answer 1

Please try the below configuration. Few changes in the haproxy.cfg
docker-compose.yaml
version: '3.3'
services:
wechat-1:
image: nginx
container_name: wechat-1
ports:
- 81:80
networks:
- web
depends_on:
- wechat-2
wechat-2:
image: nginx
container_name: wechat-2
ports:
- 82:80
networks:
- web
haproxy:
build: ./haproxy
container_name: haproxy
ports:
- 80:80
networks:
- web
depends_on:
- wechat-1
networks:
web:
Dockerfile
FROM haproxy
COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
haproxy.cfg
global
debug
daemon
maxconn 2000
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
frontend http-in
bind *:80
default_backend servers
backend servers
mode http
option forwardfor
balance roundrobin
server wechat-1 wechat-1:80 check
server wechat-2 wechat-2:80 check
Logs of HAPROXY
Attaching to wechat-2, wechat-1, haproxy
haproxy | Using epoll() as the polling mechanism.
haproxy | Available polling systems :
haproxy | epoll : pref=300, test result OK
haproxy | poll : pref=200, test result OK
haproxy | select : pref=150, test result FAILED
haproxy | Total: 3 (2 usable), will use epoll.
haproxy |
haproxy | Available filters :
haproxy | [SPOE] spoe
haproxy | [CACHE] cache
haproxy | [FCGI] fcgi-app
haproxy | [TRACE] trace
haproxy | [COMP] compression
haproxy | [NOTICE] 144/204217 (1) : New worker #1 (6) forked