How to load balance docker containers running a simple web application?
I have 3 web containers running in a single host. How do I load balance my web containers?
Put a load balancer, such as haproxy or nginx can even do the job.
Decent Haproxy Documentation
Nginx Howto
Either way, put the load balancer on the host or on a different server that can access the exposed ports on the containers. Nginx will probably be simpler for your needs.
To setup basic nginx load balancing:
http {
upstream myapp1 {
server CONTAINER_APP0_IP:PORT;
server CONTAINER_APP1_IP:PORT;
server CONTAINER_APP2_IP:PORT;
}
server {
listen 80;
location / {
proxy_pass http://myapp1;
}
}
}
Related
I am trying to configure nginx load balancer but with ip_hash method, nginx redirects users to only one server. Are there any other configurations to apply beneath the ip_hash method to distribute users to other unused servers?
We have 3 servers and backend with nginx load balancer that uses ip_hash as a method;
upstream backend {
ip_hash;
server IP:PORT;
server IP:PORT;
server IP:PORT;
}
We tried least_conn method to distribute users favourably but our application kicks users out after logging in for no reason. Tried to add a keepalive 10; but it did not work either.
I have 3 different VMs where 2 of them are running an application on Kubernetes (Minikube), on NodePort.
On the third server, I'm trying to use Nginx as a LoadBalancer but I cannot seem to reach the servers.
For that I am following the own Nginx guide using something like:
(I can access the application using NodePort on my PC)
http {
upstream backend {
server 192.168.1.1:31200;
server 192.168.1.2:31201;
}
server {
listen 80;
location / {
proxy_pass http://backend;
}
}
}
However when I connect to the LoadBalance, it cannot find the servers.
Am I configuring Nginx in a wrong way or by using a local server like Minikube it is not possible to Load Balance this way?
Turns out I had configured the DNS server wrongly, now it works as expected.
I have a nginx droplet with digital ocean acting as a load balancer.
My backend consists of a further 2 droplets (servers) which the Nginx load balancer forwards signals to vis a vis a fully qualified domain.
I wish to debug the application on the live server -- i.e. I want to keep having the customers going to one of the servers, while I debug and see what happens on the other.
The problem -- is that I do not know how to keep customers directed to the fully qualified domain while at the same time I can review the behaviour of the other IP.
My nginx is a very simple configuration:`
http {
...
upstream backend {
#server0
server IP address;
#server1
server IP address;
}
server {
server_name www.domain.com domain.com;
root /var/www/html;
# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
location / {
proxy_pass http://backend;
}
....
}
}`
Imagine that we have a web application that is running in three different servers. And we have a NginX server that has a load balancer and redirects requests to these three servers.
So what happens to requests when the NginX server is no longer running? Are they redirect to one of the servers? If not how could we redirect them to one of the servers?
If one of the load balancing instances is down, requests will still get routed to that server, because nginx has no way of knowing upstream instance is failing. You'll get 502 Bad Gateway for one out of three requests.
To avoid down servers getting requests, you can use nginx's health checks.
NGINX and NGINX Plus can continually test your upstream servers, avoid the servers that have failed, and gracefully add the recovered servers into the load‑balanced group.
In your app, you can have a path /health_check that responds with 200 Status Code if the instance is OK and use this configuration.
http {
upstream backend {
server backend1.example.com;
server backend2.example.com;
}
server {
location / {
proxy_pass http://backend;
health_check uri=/health_check;
}
}
}
My issue is that I have a web server running on port 80. I want to use nginx proxy (not the ingress) bto redirect the connection. I want to use link wwww.example.com. How should I tell nginx to proxy the connection on wwww.example.com (which is a different app). I tried using service with load balancer but it changes the hostname ( to some aws link) I need it to be exactly wwww.example.com.
If I understood your request correctly, you may just use return directive in your nginx config
server {
listen 80;
server_name www.some-service.com;
return 301 $scheme://wwww.example.com$request_uri;
}
If you need something more complex check this doc or this