# Why does Network Render require separate Master and Client roles?

As far as I understand it, this is how the Network Render addon works:

• The Client is the computer with the file to render. It connects to the master, which sends out the file and sends back the rendered images.
• The Slaves are the computers with the processing power. They connect to the master, receive and render the file, and send back the rendered images.
• The Master functions as a server. It listens for jobs and slaves, and passes images and files back and forth between clients and slaves.

It seems that the master is merely acting as a middleman. Another way to do it would be like this:

• The Master is the computer with the file to render. It listens for slaves, sends them the file, and receives the rendered images.
• The Slaves are the computers with the processing power. They connect to the master, receive and render the file, and send back the rendered images.

The second solution can be accomplished by running two copies of Blender one the same machine, with one copy as a master and one copy as a client. However, this is somewhat unintuitive, and seems to serve no purpose – it's merely adding an extra link in the network chain, albeit to localhost.

Why is the system designed as it is? Is there anything preventing it from simply using two modes? Are there any advantages to the three-mode system?

• – Aldrik Aug 12 '13 at 10:04

## 1 Answer

While anyone can make use of network rendering, the main target is for small studios. Which would be the reason this design choice was made.

Imagine a studio with 10 artists, you setup a master and several slaves for the render farm. Each artist is then a client that sends render jobs to the farm, the master keeps track of all these jobs and which slaves are working on each task giving one central point to monitor all work being done by the farm. When the artists go home they can add their machine as a slave so it can keep working through the night. In the morning they can stop it as a slave and get back to their own work.

If each artist was also a master then they would all be fighting to get the slaves to do their work for them.

For a single artist this can be excessive or awkward but is really only a minor issue.

• So the critical point is - you can have multiple clients as well. That makes perfect sense. – wchargin Aug 12 '13 at 14:51
• This is a great explanation, and I'd like to add that the Client and Master can be on the same machine. I believe you can set all of this up using the command line. – Kaninepete Jan 6 '16 at 17:25