HPC/Applications/comsol

Introduction

The COMSOL Multiphysics product is available for Mac, Windows, and Linux.

Access

COMSOL Multiphysics

Our installation of the main COMSOL Multiphysics product (the full graphical user interface and its batch computing application) is generally available to Argonne employees only, in compliance with its license agreement.

• To request access, send a request to [email protected].
• Of the available features, we have licensed a subset, shown at right.
• To have a native desktop version installed, please contact CNM support. Make sure to review Product Updates.

COMSOL Server Application

The complementary COMSOL Server product offers an alternative but more narrow means of access.

All users, including Non-Argonne persons may be able to run, over a web interface in their browser, frozen-code simulations that were made with the COMSOL Application Builder (Requires Windows). Please contact CNM support to discuss using server applications. We will review possible purchase paths for COMSOL Server, and the considerable effort likely required by users and the CNM to develop and deploy a COMSOL application.

Ways to run COMSOL

There are several ways of running COMSOL.

Running the desktop application

Model development and analysis is done using the COMSOL graphical user interface (GUI), which itself be run in several ways:

1. Run on Carbon, display on your desktop using the X Window system (X11).
   • Requires an X11 Server application running on your client machine, and SSH X11 forwarding.
   • The X11 protocol can be slow over LAN.
2. Run on Carbon within a virtual desktop environment (VNC).
   • Requires a VNC client on your machine.
   • It can be confusing where VNC and the app runs.
   • The virtual desktop presents a (deliberatly) sparse windowing environment – Copy&Paste can be difficult to use.
3. Run on your own computer, remotely checking out Carbon's license.
   • Requires a full installation of COMSOL on your client machine.
   • Access to the license servers requires VPN (fairly easy) or SSH license tunneling (can be intimidating for first-time users).

Running a batch calculation

When the computational stage of models takes longer than a few minutes to complete, it will be beneficial to submit save the model file and run it in parallel on Carbon. See the section below.

Support

For questions on how to run or start COMSOL, contact CNM IT support - see HPC/FAQ.

For questions related to COMSOL data or scripts, you may contact COMSOL support directly.

Export control

If your support question might contain data that is subject to US Export Control, contact support@us.comsol.com instead.

Use with X11

For casual use, and with X11 tunneling to Carbon set up, simply add to your ~/.bashrc file on Carbon:

module load comsol

Then, from the command line on a Carbon login node, start the COMSOL GUI:

comsol &

Comsol will use a number of cores to run calculations multithreaded by default. (On Carbon, COMSOL_NUM_THREADS is set.)

Quit the application as soon as you are done. Only one user can use Comsol at a time.

Use with VNC

See general instructions on using VNC, and the COMSOL example therein.

Running native desktop version

To get the fastest response from the COMSOL GUI, run a native COMSOL version on your desktop machine. You will have to configure it to check out a license from the Comsol license server running on Carbon.

• Edit the text file <COMSOLDIR>/license/license.dat, where <COMSOLDIR> is located by default at:
  • Windows: C:\Program files\COMSOL\COMSOL52a
  • Linux: /usr/local/comsol52a
  • Mac: /Applications/COMSOL52a

• On the client machine, use the following COMSOL license file, or enter these data into the COMSOL license configuration wizard:

SERVER cmgmt3 ANY 1718
SERVER cmgmt4 ANY 1718
SERVER csched1 ANY 1718
USE_SERVER

• Verify that these host names can be resolved to IP addresses, i.e., either one of the following commands should produce sensible output:

host cmgmt3
ping -c 3 cmgmt3

If you get errors, see the section #VNC below.

• Start the COMSOL application.

Running native desktop version – outside of the CNM

You have two ways to connect to CNM's COMSOL license server:

SSH Tunneling

If you're comfortable with ssh and tunneling, do the following on your (the client) machine:

• Enter into the COMSOL license file:

SERVER 127.0.0.1 ANY 1718
USE_SERVER

Note: Do not use "localhost", as this will be directly (and incorrectly) interpreted by COMSOL to mean that the current machine actually is a license server.

Connect to mega or a Carbon login node with one of the following ssh commands:

• First, set up a tunnel to the primary license server:

ssh  -L 1718:cmgmt3:1718  -L 1719:cmgmt3:1719  mega

• Start COMSOL.

If you get an error that the number of licenses is exhausted, that is at least confirmation that you correctly reached the license server.

If the above attempt takes a long time or hangs entirely, it may be because the license service currently runs on the secondary server.

• Connect to the alternate license server:

ssh  -L 1718:cmgmt4:1718  -L 1719:cmgmt4:1719  mega

• Start COMSOL.

Note: With SSH tunneling, the selection of an active license server from a redundant set cannot be done automatically. Instead, the user must try one server first, then the other.

VPN

Do the following on your (the client) machine:

• Enter into the COMSOL license file:

SERVER cmgmt3 ANY 1718
SERVER cmgmt4 ANY 1718
SERVER csched1 ANY 1718
USE_SERVER

• On a Mac, open System Preferences, Network. Add "cnm.anl.gov" to the DNS Search Domains, then Apply. The setting appears to be persistent and will be active the next time that this VPN session gets started.

• Start COMSOL.

Multiple CPU cores

Ways to start multi-core (from http://www.comsol.com/support/knowledgebase/1096/)

comsol -np 8

export COMSOL_NUM_THREADS=8    # automatically provided on Carbon
comsol

• COMSOL does not benefit from hyperthreading (oversubscribing the physical core count).

Batch jobs

• http://www.comsol.com/support/knowledgebase/1001/ .
• Media:HPC 2012-05-16 Comsol parallel usage.pdf (Modified from http://www.comsol.com/support/knowledgebase/1001/files/4027/cluster_install_linux_42a.pptx – Appendix slide, PBS)
• Note: MPD is not supported on Carbon (I patched the main comsol script), and no longer necessary at all in Comsol-4.3.

Sample Job file

See:

$COMSOL_HOME/sample.job