chia-garden is a utility to handle the migration of plot files for the Chia blockchain.

The difference between chia-garden and other tools out there is that most other tools will only transfer plots from a single plotting host to a single harvester host. If you have a larger farm, you then likely have multiple plotters pointing to individual harvesters. This creates more overhead to manage and be efficient.

chia-garden works off of a central message bus. With this, all plotters are able to communicate to all harvesters. Any one of your plotters can simply generate and push out plots to any of your harvesters. chia-garden works to naturally load balance plots as their produced to the harvesters with the fewest active transfers and evenly distribute them across all the disks on an individual harvester.

When a new plot file is found on a harvester, it will publish a message to NATS notifying harvesters of the file being available and noting its size.

All the available harvesters will receive this message and generate a response with a URL for the plotter to send the file to the harvester over HTTP.

Whichever harvester responds first to the plotter is the one which will have the file sent to it.

Since the plotter only takes the first response, even distribution can be naturally achieved by the harvesters responding fast or intentionally responding slow. For instance:

• If the current harvester is already transferring a few plots, its network traffic is going to be pegged, so it would be less ideal to receive it. It can delay responding by 10ms for each active transfer it already has.
• If the current harvester's disk is getting closer to filling, it might be less ideal to plot compared to a harvester with a completely empty disk. So it can add a 5-10ms delay to when it responds.
• If the harvester has no transfers and plenty of storage, no delay, respond immediately!

A number of optimizations are instrumented in how the transfers are performed.

1. The harvester nodes will prioritize disks with more free space. With this, disks will typically fill at an even rate rather than one at a time.
2. It will only allow one plot to be written to a disk at a time. This is to avoid fragmentation on the disk caused by concurrent plots being written.
3. Harvesters with more transfers will be deprioritized. This is to limit network conjestion in cases where multiple plotters are are transferring at the same time.

The main prerequisite for running chia-garden is to be running the NATS message bus. NATS is powerful, yet simple and resource efficient. If you're going big time, you can run it see the docs on how to set it up clustered. But for simplicity sake, you can simply docker run it.

$ docker run -p 4222:4222 -d nats:latest

You're now running a NATS server with port 4222 forwarding to it.

$ docker run \
    -e GARDEN_NATS_URL=nats://1.2.3.4:4222 \
    -v /mnt/plots:/mnt/plots \
    ghcr.io/krobertson/chia-garden:dev plotter --path /mnt/plots/final

$ docker run -p 3434:3434 \
    -e GARDEN_NATS_URL=nats://1.2.3.4:4222  -e GARDEN_HARVESTER_HTTP_IP=1.2.3.4 \
    -v /mnt/plots:/mnt/plots \
    ghcr.io/krobertson/chia-garden:dev harvester --expand-path /mnt/plots

chia-garden can use environment variables in the place of command line arguments. This can be a bit simpler to set values when running it within Docker.

• GARDEN_NATS_URL: The nats connection string.
• GARDEN_HARVESTER_HTTP_IP: The IP address the harvester command should use to identify itself.
• GARDEN_HARVESTER_HTTP_PORT: The port the harvester command should use to listen for transfer connections on.
• GARDEN_HARVESTER_MAX_TRANSFERS: The maximum number of transfer the harvester command should allow at a time.
• GARDEN_PLOTTER_MAX_TRANSFERS: The maximum number of transfer the plotter command should allow at a time.
• GARDEN_PLOTTER_SUFFIX: The suffix to use to identify plot files. Default is plot, can be updated to drplot for DrPlotter.