In this post, I will talk a little about OnionBalance, a load balancer in TOR network. It enables adding multiple hidden services which can be accessed from one Onion Address.
(The picture is from Life Hacker)
A Small Description
If you want to know more about TOR network and hidden services, you can check my previous posts in Anonimity Category.
The idea of load balancing is about serving a service (such as Web service) using multiple instances (web servers). Load balancing helps users to wait less (for loading of a web page) and less traffic and load on the server.
This is the general idea of a web load balancer:
In normal load balancing schema, a DNS server can resolve the same domain name to multiple IPs using a load balancing algorithm (such as Round Robin), but in TOR network, there is no DNS server. The hidden services are served by HSD (Hidden Service Directories). You can get more information from this link.
Therefore, Bob (who owns a hidden service) register its Introduction Points in the HSD (or the DB in picture). But Bob runs a hidden service with one address. What is Bob has more hidden services (same instance)?
Onion Balance
If Bob can run multiple hidden services and ask HDSs to change the Introduction Points of the multiple hidden services to only one Introduction Point, then the one address will be transferred to IP of the 1st hidden service or the 2nd or the 3rd, etc.
This is how the Onion Balance (and similar tools) works.
Running Onion Balance
I made a video tutorial about running onion balance. If you have any question, feel free to ask.