Running COMSOL on Clusters

You can launch COMSOL cluster jobs from the COMSOL Desktop and the command line. To run COMSOL on a cluster, you need to make the cluster feature visible: in the Model Builder tree, click the Show button () and select Advanced Study Options. Then in the Model Builder, right-click a Study node and select Cluster Computing or Cluster Sweep to create cluster jobs. Cluster computing requires a Floating Network License.

The following terms occur frequently when describing the hardware for cluster computing and shared memory parallel computing:

•	Compute node: The compute nodes are where the distributed computing occurs. Each distributed COMSOL process resides in a compute node and communicates with other compute nodes using MPI (message-passing interface).

•	Host: The host is a physical machine (hardware) with a network adapter and unique network address. The host is part of the cluster. It is sometimes referred to as a physical node.

•	Core: The core is a processor core used in shared-memory parallelism by a computational node with multiple processors.

The number of used hosts and the number of computational nodes are usually the same. For some special simulation types, like very small simulations with many parameters, it might be beneficial to use more than one computational node on one host.

A tutorial model for cluster testing is included in the Application Libraries window under COMSOL Multiphysics>Tutorial models>micromixer_cluster.

quick troubleshooting

•	Your first step is to make sure you have the latest release installed. Check that you have COMSOL 5.2a or later and make sure to install the latest product updates.

•	If you get the error message Process status indicates that process is running, then cancel any running jobs in the scheduler that you use. In the COMSOL Desktop, locate the External Process page at the bottom right. Click the Clear Status button.

For more information about how to run COMSOL in parallel on Linux clusters, see the COMSOL Multiphysics Reference Manual. For installation on Clusters, see Cluster Installation.