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Question
My MIKE 21/3 FM setup cannot execute anymore. It worked yesterday. Why?

Answer
By default, a MIKE 21/3 FM model simulation runs using the same number of subdomains as there are cores in the PC. When using more than one subdomain in the calculation the model engine uses the MPI Runtime library.

Note: The default simulation settings can be changed under 'User Settings'.

There can be 3 main reasons why your MIKE 21/3 FM setup cannot execute:
 
#01 - The MPI Runtime version 
If MIKE FM suddenly stops (or goes from 0 to 100% in an instance) it could be related to the MIKE Software finding the wrong version of the MPI Runtime Library. This can occur if another software package with an MPI runtime library has been installed after the MIKE Zero installation.
 
The Intel MPI Runtime Library installed together with the Release 2021 Update 1 and Release 2022 of the MIKE software is: Intel MPI Version 2019 and is located in the folder: C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2020.0.166\windows\mpi\intel64\bin

The MIKE software is expecting to find this exact version of the MPI Runtime Library. This means that the Intel MPI Runtime Library installed by the MIKE software should be the first MPI Library listed in the PATH environment variable. If a different MPI Library is listed in the PATH before the version installed by MIKE, then MIKE Software will find this “wrong” version instead. If this is the case, try to uninstall the MPI Runtime Library using the Control Panel - see example in Fig. 1

After uninstalling the MPI Runtime Library, select the original MIKE Zero installation file and choose ‘Repair’ in the dialogue (see right figure below). This will re-install the now missing MPI Runtime Library and place it first in the PATH
environment variable.


Fig. 1 - Uninstall MPI from control panel

Alternatively, you may try to modify the PATH environment variable directly so that  the MPI Runtime Library installed together with MIKE Zero is the first MPI Library listed in PATH.
 
You can investigate the MPI settings in more detail by the following commands from a command prompt.

1) where mpiexec:
C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2020.0.166\windows\mpi\intel64\bin\mpiexec.exe
 
2) mpiexec -version
Intel(R) MPI Library for Windows* OS, Version 2019.0.6 Build 20191024
Copyright (C) 2003-2019, Intel Corporation.
 
3) path
C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2020.0.166\windows\mpi\intel64\bin
 
#02 -  Special characters
Special characters in filename and path may work OK in some parts of the MIKE software. However,  the mpiexec command does not work with special characters in the filename.
 
E.g. take a model setup called ‘Øresund.m21fm’. This needs to be executed using 4 subdomains. A batch file placed in the same folder as the setup will look as follows - see example in Fig. 2

 
 
Fig. 2 - A batch file placed in the same folder as the setup

When running this from a command prompt, the special character in the filename will be translated by the system so it becomes unrecognizable, and the simulation cannot start - see example in Fig. 3

 

Fig. 3 - Unrecognized file names

If you start an execution using several subdomains from a User Interface (via the editor or MzLaunch) the programme will create a command string to mpiexec using the absolute file path. Consequently, in this instance, special characters in the path to the setup file are not permitted either.
 
#03 - Firewall settings
Ensure that the Firewall settings for mpiexec and the related MIKE FM engine are enabled. In some cases, it requires access to public use for this to work.
 
 
Fig. 4 - Enable public use for mpiexec 
 

FURTHER INFORMATION & USEFUL LINKS

The Intel MPI Runtime Library installed together with the Release 2020 Update 1 and Release 2021 MIKE software is: Intel MPI Version 2019.
Location: C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2020.0.166\windows\mpi\intel64\bin

The Intel MPI Runtime Library installed together with the Release 2019 and Release 2020.0 MIKE software is Intel MPI 2018.1.156.
Location: C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2018.1.156\windows\mpi\intel64\bin 

The Intel MPI Runtime Library installed together with the Release 2017 MIKE software is Intel MPI 2017.0.109.
Location: C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2017.0.109\windows\mpi\intel64\bin 

The Intel MPI Runtime Library installed together with the Release 2016 MIKE software is Intel MPI 5.1.1.110.
Location: C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2016.0.110\windows\mpi\intel64\bin 

Related Products: MIKE 21/3, MIKE+