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Fluent UDF on parallel computing

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Old   December 14, 2013, 09:39
Default I think there is a varaible lock
  #21
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Saâd Debbahi
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Hi,

I faced this problem when trying to run udf in parallel mode, pay attention to the code enclosed between the parallel directives (if RP_NODE......end if), within this code section "try to eliminate instructions that modify common variables values".

her is an illustrative example

Code:
real k_sqr,kx,ky,kz,amp;

#if RP_NODE
k_sqr=kx*kx+ky*ky+kz*kz;
amp=2;

#end if
when running such code, these operations

Code:
k_sqr=kx*kx+ky*ky+kz*kz;
amp=2;
are going to be performed by all the computing nodes, for example when "node 1" accesses the variable k_sqr to modify it according to the formula of k_sqr, the system locks this very same variable/resource so that the access to it is denied to all of the other nodes once one of them is using k_sqr, this is a lock on this resource, which can't be manipulated by more than one process "simultaneously". I think the error is due to the access denial for the nodes trying to perform the parallel tasks while variables are used/locked by a very specific node. your last post confirms it

Code:
999999 (../../src/mpsystem.c@1123): mpt_read: failed: errno = 104

999999: mpt_read: error: read failed trying to read 30 bytes: Connection reset by peer

The fluent process could not be started.
it sais failed to read 30 byte.
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Old   December 20, 2013, 12:06
Default Convert a serial UDF to parallel
  #22
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Tanjina Afrin
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Dear All,

This is my serial UDF. After reading the manual I am getting confused with int ex node and stuff. Could anyone please convert this UDF to parallel? It is working properly for serial system.

#include "udf.h"

DEFINE_PROFILE(pressure_profile,t,i)
{
real x[ND_ND];
real y;
face_t f;
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
y=x[1];
F_PROFILE(f,t,i)=(0.4898-y)*998.2*9.81;
}
end_f_loop(f,t)
}

And I will use Cluster which is in Linux system. How can I make the UDF visible to every node??

Thanks a ton in advance.

Tanjina
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Old   August 12, 2015, 08:44
Exclamation parallel
  #23
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frety
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hey
can anyone could help me to make my udf parallel?

DEFINE_PROFILE(porosity_function,t,j){
real x[ND_ND];
cell_t c;
begin_c_loop(c,t){
C_CENTROID(x,c,t);
if(pow((x[1]-yo[0])/R,2)+pow((x[0]-xo[0])/R1[0],2)<=1 )
F_PROFILE(c,t,j)=0.9;
else
F_PROFILE(c,t,j)=0.1;
}
end_c_loop(c,t)
}
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