Optistruct MPI executables - Multi Model Optimization

Benjamin Joemann_20337

Hallo,

 

I am currently trying to get a Multi-Model Optimization to work. For this purpose I am following the example OS-E: 0830 excavator arm. I have the .fem files of the example, but my problem seems to be more fundamental. If i want to start a MMO run from the Hyperworks Solver Run Manager it says:

 

Solver arguments not accepted:

Error in command line:

No useful executable found in:

/Programme/Altair/hwsolvers/optistruct/bin/win64

This is likely cause by unsupported MPI version i

 

And indeed, I dont have any optistruct executable ending in '_impi' in this folder. But I do have an 'mpi' folder under Altair/mpi. My command line options to start the master.fem are:

 

-out -mmo -np 3 -mpipath {D:/Programme/Altair/mpi/win64/intel-mpi/bin}

 

My guess is that there is some fundamental step I have no clue about to obtain an mpi executable. Or is this file missing in the student version?

 

Admittedly this is the first time I work with MPI. So any help guiding me in the right direction is appreciated!

 

Best regards,

 

Benjamin

QuyNguyenDai

Tell us about your hardware? Do you have a HPC? or only a PC with multiple cores?

Remember: SPMD is multi-nodes multi-processors parallel computing used with a HPC via MPI.

When you have only a PC with several cores, you can use 'SMP' mode instead.

 

Adriano_Koga

In this case it should work even in a single cpu, multi-core.

MMO would launch each model in one core and run multiple jobs in parallel.

 

Maybe it is related to the student version.

OptiStruct full has an embed mpi in its installation..it should call it by default.

Maybe it is a limitation of student edition.

Benjamin Joemann_20337

I am currently using the optistruct student version on a PC with multiple cores.

The solver executables I have under /Programme/Altair/hwsolvers/optistruct/bin/win64 are:

-optistruct_2019_win64.exe

-optistruct_2019_win64_cuda.exe

-optistruct_2019_win64_h3d19.exe

-optistruct_2019_win64_i64.exe

 

I think in this folder there should be another exe, ending in _impi or something similar. Maybe you Optistruct Full users can verify?

QuyNguyenDai

You not need MPI. Only SMP mode is ok.

Benjamin Joemann_20337

Q.Nguyen-Dai, I believe that this is unfortunately wrong. Indeed I have already used the SMP capabilit of Optistruct in the past by adding '-nt 4' to my run options, to make use of my different cores. However, in this case I am trying to run a Multi-Model Optimization. For this it says in the Optistruct user guide:

 

'[...]. Multi-Model Optimization is a MPI-based parallelization method, requiring OptiStruct MPI executables for it to run. Existing solver decks do not need any additional input, can be easily included, and are fully compatible with the MMO mode. [...}'

 

Hence in the example they define a master.fem input deck like this:

 

$
SCREEN OUT
$
RESPRINT ALL
$
ASSIGN,MMO,bucket,excavator_bucket.fem
ASSIGN,MMO,hammer,excavator_hammer.fem
$
BEGIN BULK
$
ENDDATA

 

This deck then needs to be executed with the '-mmo' run option, which in turn requires MPI executables.

 

Maybe some one can shed some light on wether the student version is the issue here?

QuyNguyenDai

For any FE solvers, you can run SPMD with MPI on multi-cores processor, but you win almost nothing about computing performance.

MPI is designed firstly for multi-nodes system (HPC).

Benjamin Joemann_20337

Okay, I see. So basically I wouldn't need to use MPI on my single PC if it wouldn't be for the fact that Optistruct requires it when performing MMO.

 

Anyway, luckily my university offers Optistruct SPMD on their compute cluster, so I can solve my models there.

QuyNguyenDai

Yes, that makes sense to use SPMD computing on a HPC