Hosting Firefly on a Cluster Environment

Firefly can easily be hosted on a cluster environment for two main benefits:

• Snapshots that are stored on the cluster can be rendered without having to transfer them
• Firefly can be embedded into an iframe within a Jupyter notebook hosted on the cluster

The polite thing to do is to host from within an interactive session on a compute node, but a login node will work as well (and since calculations occur within the browser it is mostly inoffensive).

Note that this is the identical process to hosting a Jupyter notebook remotely on a cluster and accessing it through your local machine.

Host the server

Identically to how you would host a SimpleHTTPServer using Python in order to run Firefly on Chrome, navigate to the Firefly directory where index.html is on the cluster and execute:

$ python -m SimpleHTTPServer xxxx

Where xxxx is a 4 digit port of your choosing, omitting the port will default to 8000.

The server can also be hosted within a Jupyter notebook, as described here.

Port-forward the localhost port you chose

Next, you must connect localhost:xxxx on the cluster to your local machine's localhost:xxxx. This can be done from the terminal using ssh -L in two parts, first from the local machine to the login node and then from the login node to the compute node. With a simple alias in your .bashrc this can be combined into a single command:

alias s2firefly='ssh -L xxxx:localhost:xxxx [email protected] ssh -L xxxx:localhost:xxxx'

Which is executed like:

$ s2firefly YYY

Where YYY is the hostname of the compute node. This command will open a pseudo-terminal once you login, it is not necessary to do anything once the connection is established but closing the terminal window will terminate the port-forwarding.

Visit the port on your local computer

Navigate to localhost:xxxx on your computer's browser and enjoy Firefly!