Running in parallel FLOW (FLOW2D3D Version 6.02. - 01_standard example) - Forum - Delft3D

Hi Juan,

example "01_standard" is too small to run with more than 5 partitions. When "max(mmax,nmax)/npart <= 4", the computation will not run.

Regards,

Adri

Hi Juan,

Flow does that for you and echoes an error message in the "tri-diag"-file.

If you want to check it manually:
mmax and nmax are the dimensions of your grid (mdf-file, line "MNKmax", for example "MNKmax= 15 22 5"), npart is the number of partitions that you have chosen (for example 5 or 6), so in this example "max(15,22)/5 = 4.4" is bigger than 4 will run fine and "max(15,22)/6 = 3.666" is smaller than 4 and will stop with an error message.

Regards,

Adri

Hi Adri! Thanks again for your explanation!

In this case my MNKmax variable is 583 335 14. If I apply your explanation, I got the following -> 583/14 = 41.642. That means that I can use 14 cores to run this simulation.

Unfortunately the only way that I could ran this simulation was using just 1 core,  so when I used more cores it failed and I got the following errors on the tri-diag files:

*** WARNING Ratio in layer thickness of the two bottom layers is larger than 1.5.
            May lead to inaccurate representation of the bottom boundary layer.
*** MESSAGE Upwind advection scheme only near momentum discharges
*** WARNING Discharge (m,n,k)=(42,311,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(70,252,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(79,243,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(231,163,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(254,248,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(317,64,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Discharge (m,n,k)=(481,180,0) is disabled: inlet and/or outfall not in this partition
*** WARNING Using Smoothing time and initial condition file
*** MESSAGE Ocean heat model: Stanton number specified to be    0.10000E-02
*** MESSAGE Ocean heat model: Dalton number specified to be    0.10000E-02
*** MESSAGE Using UNESCO density formulation by default
*** MESSAGE Evaporation not taken into account in continuity equation
*** MESSAGE Number of pivot points to convert wind speed to wind drag coef.: 2
*** MESSAGE Updating tidal node factors every   0.6000E+02 [min]
*** MESSAGE Momentum solver cyclic method is specified
*** MESSAGE DRYFLP and DPSOPT both specified in MD-file. Using DPSOPT: MEAN
*** MESSAGE Transport solver cyclic-method method is specified
          remap n=  19 mnit1 =    1 334 mint2 =   14 334 - node number 005
          remap n=  20 mnit1 =   14 334 mint2 =   29 334 - node number 005
*** MESSAGE His, map, drogue, and fourier files written in single precision (except for time and horizontal coordinates).
*** MESSAGE Uniform wind and pressure specified
*** MESSAGE Heat model: Secchi depth specified to be   30.0000000 m
*** ERROR Drogues/walking monitor points are not available in parallel computations
*** ERROR Flow exited abnormally

I attached the mdf file and one of the tri-diag files to explain better this case.

Regards,

Juan.

Hi Juan,

Unfortunately the combination of drogues (line "Filpar= #117.par#" in your mdf-file) with parallel computation is not implemented yet. If you remove the drogues, I expect the parallel computation to run.

Regards,

Adri