Are later versions of the Front-End compatible with older Kernels?

Question

At my graduate school, all of the clusters still use version-6, and I only have version-7 and version-8 installed on my computer. I would like to use those machines remotely. Are either of the versions I have compatible with the version-6 kernel?

Answer 1

The best thing to do is to test whether you can make the connection manually:

Start Mathematica on your local machine. On the toolbar, navigate to Evaluation ► Kernel Configuration Options. Add a new kernel and configure it. In the dialog, click on Add ... and a Kernel Configuration dialog appears. Enter an appropriate name for your remote kernel. Under Basic Options, verify that Launch On is set to Local machine. Additionally, clear the field, Kernel program. Click on the Advanced Options switch. In the text field called Arguments to MLOpen, enter:

-LinkMode Listen -LinkProtocol TCPIP

Click OK and open up a new Mathematica notebook. On the toolbar, navigate to Evaluation ► Notebook's Kernel and click on the name of the kernel that you just created. Evaluate the command:

$Version

inside the notebook. Instead of printing Mathematica's version number, a message box appears:

MathLink Alert
Link created on:

After this message is a string of characters. This string of characters is a linkname. Record the linkname so that you can use it later, and click OK to close the dialog. The title bar of the notebook should still say Running... at the top.

While, the local machine is still running that notebook, connect to the remote machine and launch the Mathematica kernel. Inside the kernel, run the command:

$ParentLink = LinkConnect["linkname", LinkProtocol->"TCPIP"]

Where "linkname" is the linkname you recorded earlier in quotation marks. For example, if the linkname you saw was:

port1@machine.domain.com,port2@machine.domain.com

You would run:

$ParentLink = LinkConnect[
                "port1@machine.domain.com,port2@machine.domain.com",
                LinkProtocol->"TCPIP"]

The notebook that is open on the local machine prints out the version of Mathematica you remotely connected to. This indicates that the local machine is successfully using the remote kernel.

Answer 2

Yes, older kernels are compatible with newer front ends. I think this is why the Version5`Graphics`, Version6`Graphics` and Version7`Graphics` packages exist. (Simply to ensure compatibility of graphics. From a short look at .tr files once I got the impression these get loaded when older kernels are used.)

Regarding managing to create a connection, the Remote Kernel Strategies package is the most robust and most hassle-free approach I know.

Unfortunately when I use a remote kernel, my front end tends to freeze occasionally, but others didn't manage to reproduce this, so you may be safe. Just try the dynamic example from that link to test this.