Using HAProxy, I'm trying to (TCP) load balance Rserve(a service listening in TCP socket for calling R scripts) running at port 6311 in 2 nodes.
Below is my config file. When I run HAProxy, its statting without any issues. But when I connect to the balanced nodes, getting below error. Anything wrong with the config?
Handshake failed: expected 32 bytes header, got -1
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode tcp
log global
option httplog
option dontlognull
option http-server-close
#option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
listen haproxy_rserve
bind *:81
mode tcp
option tcplog
timeout client 10800s
timeout server 10800s
balance leastconn
server rserve1 rserveHostName1:6311
server rserve2 rserveHostName2:6311
listen stats proxyHostName:8080
mode http
stats enable
stats realm Haproxy\ Statistics
stats uri /haproxy_stats
stats hide-version
stats auth admin:password
Tried with below frontend-backend way of balancing as well. Same result.
frontend haproxy_rserve
bind *:81
mode tcp
option tcplog
timeout client 10800s
default_backend rserve
backend rserve
mode tcp
option tcplog
balance leastconn
timeout server 10800s
server rserve1 rserveHostName1:6311
server rserve2 rserveHostName2:6311
After struggling for a week for a solution to load balance R, below (full free/open source software stack) solution worked.
If more people are referring this, I'll post a detailed blog on installation to configuration.
Was able to load balance R script requests coming to Rserve via HAProxy TCP load balancer with the below config. Pretty much similar to config in question section, but with frontend and backend separated.
#Load balancer stats page access at hostname:8080/haproxy_stats
listen stats <load_balancer_hostname>:8080
mode http
log global
stats enable
stats realm Haproxy\ Statistics
stats uri /haproxy_stats
stats hide-version
stats auth admin:admin@rserve
frontend rserve_frontend
bind *:81
mode tcp
option tcplog
timeout client 1m
default_backend rserve_backend
backend rserve_backend
mode tcp
option tcplog
option log-health-checks
option redispatch
log global
balance roundrobin
timeout connect 10s
timeout server 1m
server rserve1 <rserve hostname1>:6311 check
server rserve2 <rserve hostname2>:6311 check
server rserve3 <rserve hostname3>:6311 check
If SELinux is enabled, the below command will enable remote connections for HAproxy
/usr/sbin/setsebool -P haproxy_connect_any 1
The firewall ports might need opening too:
firewall-cmd --permanent --zone=public --add-port=81/tcp
firewall-cmd --permanent --zone=public --add-port=8080/tcp
Also, enable remote connections in Rserve with remote enable in the Rserve config file.