COMSOL 4.3 Server License
Alke Stilwell
When a user runs an application via the web browser or COMSOL Client, their own computer or mobile device does not need to perform the multiphysics calculations. These can all be done on the server computer(s). Since you are controlling the access and use of applications through a centralized hub, any changes or updates you make are immediately available to all users. You can run up to four application sessions per concurrent user.
A COMSOL Server setup consists of a Client through which the user can access and run the applications, a primary server in which the client access is handled, and application servers where the applications and hence the computations are run.
The clients are run by the COMSOL Server users, either through a web client hosted by COMSOL Servers primary server, or through the freely available COMSOL Client which provides a desktop application able to connect to the COMSOL Server installation.
The primary server hosts the COMSOL Server web service, handles the user database, and takes care of the connections to the application servers.The application servers handles the execution of the COMSOL applications and therefore also the underlying computations. The applications can run either on the primary server or on any of the secondary servers available. For this purpose the primary server includes a workload manager that makes sure that the workload is distributed evenly between the available computers.
When running COMSOL Server in single server mode, i.e. without using secondary servers to spread the workload on multiple machines, no considerations are needed with regards to open ports and shared directories. The communication between the different parts of the COMSOL Server is performed internally. This means that no network access is needed when sending data between the COMSOL Server and the Application Server.
When running COMSOL Server in primary/secondary server mode, it is possible to run application servers on computers other than the primary server. To guarantee that communication is error free, we recommended to set up all servers, primary and secondary, with an unrestricted internal network.COMSOL will start application servers on both the primary and secondary servers on port numbers higher or equal to that of the specified service port. The service port can be specified with the command line option -serviceport XXXX.
In order for the secondary servers to access applications uploaded to the COMSOL Server installation, it is necessary to provide all servers with a shared storage. On Linux machines, such a shared storage can be set up with an NFS share. On Windows machines, a shared folder can be used.
To enable users on an internal network to access the COMSOL Server installation you need to grant them access to the service port of the primary server. Through this service port they will be able to access the COMSOL Server and the applications hosted on the COMSOL Server, either through the web interface or through the COMSOL Client.
If you are using both primary and secondary servers, it is recommended to restrict access to the secondary servers for all users to keep the internal network of the COMSOL Server inaccessible for everyone except the administrator. This increases both security and reliability, since it prohibits users from using the secondary servers for other purposes than COMSOL Server.
In order to increase security, you might want to put the COMSOL Server and any secondary servers inside a demilitarized zone, or DMZ, whenever you want to expose your COMSOL Server installation to external users. This would mean to separate the network in which your COMSOL Server is running from the network used for your internal services.
It might be practical to make the COMSOL Server installation reachable through a host name e.g. my-comsolserver from all of the computers in your network. To do this, you need to configure your DNS server. Refer to the documentation of your DNS server for instructions on how to do this.
The SLURM option -N is setting the number of physical hosts and the option --ntasks-per-node is setting the number of compute nodes per physical host. The COMSOL option -mpibootstrap slurm instructs COMSOL to deduce the COMSOL specific parameter -nn from the SLURM environment (the value for the number of threads -np will be set automatically to the optimal value, that is using all available resources). In the example above, we get -nn 8 and -nnhost 2. The system variable FLROOT needs to be set to the COMSOL installation path (given by the variable COMSOLINSTALLPATH set by the user, for example to /usr/local/comsol61/multiphysics, in this example). The variable MODEL_PATH needs to be set as well.
These errors typically occur when the COMSOL user interface Java component is trying to display an error message in a graphical window, but there is no graphical display available. The error indicates a problem during the startup of the Eclipse runtime in the COMSOL configuration directories. You can check for log files of the form .comsol/v61/configuration/comsol_/.log. In order to work around the problem, open the following three COMSOL *.ini configuration files in a text editor:
If you are using a roaming profile or a network based filesystem, the problem might be fixed by using file locations on the local machine instead. The suffix _@process.id is important to avoid conflicts between different processes. If you do not have write permissions in the installation folder, the modified *.ini files can be placed into a user defined directory and the path can be handed over via the -comsolinifile flag when launching COMSOL. As an alternative to modifying the *.ini-files, you can use the -configuration and -data flags on startup. Note that the paths for configuration and workspace should not point to existing directories with important data as the directories might be cleared.
The command above should be issued on one line. /usr/local/comsol61 is assumed to be your COMSOL installation directory. The /usr/local/comsol61/multiphysics/bin directory, where the comsol script is located, is assumed to be included in the system PATH. Make sure you have write permissions for ./out.mph. No error messages should be produced, or you may have a license manager connectivity problem.
Go to the Config Services page. Change the paths to lmgrd.exe, and license.dat so that they all point to the COMSOL 6.1 installation directory. Starting with the version of the Flexnet distributed with COMSOL Multiphysics 5.4, the permissions where the license manager is allowed to write has been changed. The current recommendation is to store the debug log file, comsol61.log in the directory C:\ProgramData\COMSOL.
Stop the COMSOL license manager: Make the comsol60/multiphysics/license/$arch directory the current directory, where $arch is either glnxa64 (64-bit Linux), glnxarm64 (ARM Linux), maci64 (64-bit macOS), or macarm64 (ARM macOS). Stop the 6.0 license manager with the lmdown command:
Note: If running the lmgrd command returns the error message ./lmgrd: Command not found., the license server is missing required libraries for LSB (Linux Standard Base). For information on how to fix this issue, please see solution 1199
This note is to show the way of using MATLAB, COMSOL,COMSOL Livelink With MATLAB on our server (ubuntu). We hope that we can run them with bash code in background and after we logout or exit the server the simulations will continue. We also need to know the simulation progress from a log file. These needs can all be satisfied only if you write proper bash code.
If you write the bash code on windows then upload the file to the server, when you try to run the bash file there may be error: /bin/bash^M:bad interpreter:No such file or directory, this is because of the difference of coding in Unix and Windows. You can use the following command in the corresponding folder to fix it
e2b47a7662