If you need to spin up a quick environment for load balance Linux systems, Linux Virtual Servers is a good way to do it. It should be built into your Linux kernel, but you'll need the command line front end to configure it. In addition, you'll need two Linux servers to use as your pool of real servers along with a third server that will function as your load balancer (referred to as a director). Hint: virtual machines are great for this.
On your machine which functions as a director you'll need the command line utility for configuring LVS. Get it with:
$ apt-get install ipvsadm
Clone this project with:
$ git clone https://github.com/arcanericky/lvs-example.git
You'll be giving your director an additional IP address called an IP alias. Be sure to use one that's not already on the network. Choosing an IP address in the same subnet and adding 1 to the last octet will probably work. If you need help finding an available IP address on your subnet, LVS may not be for you.
Modify the lvs-director-setup.sh script to reflect the subnet and last IP octet of the IP alias you'll be using for your director along with the incoming port to balance.
DIRECTOR_SUBNET=192.168.139
DIRECTOR_ALIAS_OCTET=131
DIRECTOR_BALANCE_PORT=2202
Then modify the IP addresses and destination ports of your real servers.
REALSERVER1=192.168.139.132:22
REALSERVER2=192.168.139.129:22
Execute the script as root on your director and the last lines should look something like this:
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.139.131:2202 rr
-> 192.168.139.129:ssh Masq 1 0 0
-> 192.168.139.132:ssh Masq 1 0 0
Incoming connections are now balanced to your real servers but your real servers won't know how to talk back, so let's configure them next.
The real servers need to be configured with a route to get back to the director. Modify the lvs-realserver-setup.sh with the director's IP alias and execute as root. You should see something like this:
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.139.130 0.0.0.0 UG 0 0 0 eth0
Your connections should now be load balanced using round robin.
How to setup LVS:
https://dev.to/douglasmakey/how-to-setup-simple-load-balancing-with-ipvs-demo-with-docker-4j1d