How to find which machine rendered a specific frame in a render farm

Question

I have 6 servers rendering the same project (not using the Network Render add-on). All of the servers are exporting into a shared network folder.

Some frames have issues; how can I find the faulty machine?

Answer 1

You can do this by adding custom metadata to the image using a Python script that is executed by each server. In the network folder, create a script named metadata.py with the following code:

import bpy, socket

name = socket.gethostname()

bpy.context.scene.render.use_stamp_note = True
bpy.context.scene.render.stamp_note_text = name

In your render command, add the -P flag with the path to the script, e.g.

blender -b path/to/file.blend -P path/to/metadata.py -o path/to/image.png -a

This stores the name of the machine in the "Note" section of Blender's metadata. You can view the metadata as described here to see which server is giving you trouble.

Answer 2

I don't know a very efficient way to do this, but in case you can't find a better solution you could have each machine render the same frame, then look which machine was unable to render it properly.