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Coupled model WRF+NEMO_3.6+OASIS freezes

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Posted by Anonymous at April 5 2017

I am trying to launch NEMO_3.6+WRF+OASIS:

mpirun -n 8 ./wrf.exe : -n 8 ./nemo.exe : -n 2 ./xios_server.exe

The model freezes at the very begining. wrf.exe and nemo.exe ENTER oasis_mpi_barrier and xios_server.exe ENTER oasis_get_intercomm. It seems oasis_get_intercomm module is what causes the model to hang. There are no error messages in output files.

The last message from xios_server.exe is oasis_get_intercomm :

cdnam : oceanx il : 2 mpi_root_global(il) : 1 mpi_comm_local : -2080374782

Does anyone have any idea of what could happen?

Posted by Anonymous at April 6 2017

Hi,

Fisrt, did you :

- compiled XIOS with the option oasis3mct ?

- put the coupling flag to true in the namelist of XIOS ?

If it is the case, you can try to change the order of the executables as already experimented in the conversation : 
https://www.cerfacs.fr/site-oasis/forum/oa_main.php?c=94

Let me know if this solve your problem,

Best regards, Laure

Posted by Anonymous at April 8 2017

Do you have the correct setting in the "using_oasis" entry of the iodef.xml file? (i.e.true). Failing to set that can lead to failures with very little in the way of error messages. (Also the "using_server" option might be worth checking). 

It's worth checking the contents of the XIOS iodef.xml file to see that:

variable id="using_server" type="bool"

and

variable id="using_oasis" type="bool"

and

variable id="oasis_codes_id" type="string"

are set appropriately.


To be more precise, "variable id" are defined in XIOS iodef.xml in context id ="xios". 

For example:

  

    

      

       true 

       true

        trip,surfex,oceanx  

      

    

 

Where trip,surfex,oceanx are the component names in the call to oasis_init_comp (compid, comp_name, ierror, coupled, commworld) by the component.

Posted by Anonymous at April 10 2017

Thank you for the assistance.

I figured it out. XIOS was not compiled properly. It was written in the tutorial " --use_oasis 'oasis3' 'oasis3_mct' to use Oasis coupler" So I used ./make_xios --use_oasis='oasis3_mct' instead of ./make_xios --use_oasis oasis3_mct There was no error messages from the compiler and I believed that XIOS was compiled in coupled mode but in fact it wasn't.

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