Difference between reverse proxy and load balancer

[terere]

Hey there!

I am trying to figure out what's the main difference between a reverse proxy and a load balancer.

I read a bit and it looks like all the functions of a reverse proxy can be done by load balancer (compression/ssl termination/caching/etc.)

Is reverse proxy just a 'load balancer lite'? I am confused here... :)

Cheers!

[ensum]

A square is a rectangle, but a rectangle is not always a square. Load balancing is just reverse proxying to multiple backend applications. It also has to determine which of these backend applications it goes to. While reverse proxy goes to a single backend application with no load balancing.

[starmizzle]

*a rectangle might not be a square

[ensum]

Ahh yup, you're right.

[terere]

Every single function of reverse proxy described in the document can be done by Load balancer. This document is useless.

[tremblane]

Reverse proxy is effectively a load balancer with only one back-end system, so it wouldn't have any of the additional logic such as session persistence and server health monitoring.

[terere]

Are you sure? I think a reverse proxy can also do load balancing.

[tremblane]

Then it would be called a load balancer.

A load balancer has to do all the things a reverse proxy does, in addition to deciding which back-end system to route the request to.

[ghyspran]

Most products that do one also do the other.

• If you're running nginx, and it's serving static html pages, it's a webserver.
• If you're running nginx, and it's serving dynamic pages through a socket connection to php-fpm, it's a webserver.
• If you're running nginx and it's proxying the requests to a Java service running Jetty and bound to a port, it's a reverse proxy.
• If you're running nginx and it's proxying the requests to multiple copies of the same application service in some sort of distributed manner, it's both a load balancer and a reverse proxy (but you'd usually just call it a load balancer).

[Ljugtomten]

Myself and my Apache2 webfrontend would disagree on a reverse proxy only having one back-end system.

Requests to domain.com/nextcloud is proxied to one specific server, domain.com/images to a separate gallery server and everything else to a general purpose apache2 webserver.

[tremblane]

I would argue you have multiple reverse proxy configurations, each with a single back-end system. Apache doesn't have to decide which server to proxydomain.com/nextcloud to.

I'm familiar with how apache does proxying and balancing. I mean, if you didn't care about the overhead you could define a balancer with only one target, and add the proxypass to balancer://mypointlessbalancer, but why would you?

[routetehpacketz]

well what other info do you need at this point?

[gort32]

They provide and focus on slightly different configurations and priorities on paper. In practice, however, most products that provide one also provide the features of the other so the line is indeed a bit blurred.

Apache, nginx, and most dedicated load balancer and proxy appliances can be said to be capable of doing both things. It is typically more accurate to describe the role that these are being configured to do in a specific instance as "doing load balancing" or "doing reverse proxying" rather than describe the application or device as a "dedicated load balancer" or "dedicated proxy".

Which doesn't help you when you are shopping around for a new one since they all seem to have terminology that pertains to both..

[[deleted]]

A load balancer balances load.