= HPC-05_mcastril_MPI_optimization

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The PI is responsible to closely follow the progress of the action, 
and especially to contact NEMO project manager if 
the delay on preview (or review) are longer than the 2 weeks expected.

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== Summary

||=Action       || HPC-05_mcastril_MPI_optimization                      ||
||=PI(S)        || Miguel Castrillo                                      ||
||=Digest       || To reduce the overhead caused by MPI communications in NEMO    ||
||=Dependencies || None ||
||=Branch       || source:/NEMO/branches/{YEAR}/dev_r{REV}_{ACTION_NAME} ||
||=Previewer(s) || Italo Epicoco                                         ||
||=Reviewer(s)  || Italo Epicoco                                         ||
||=Ticket       || #XXXX                                                 ||

=== Description

Assessment  of  the  model  sensitivity  to  the  network  latency, revealing  the  impact  of  internode  messages  on  the  model  scalability. Different strategies will be evaluated, as reducing  internode communication  time  and  frequency, limiting  the  communication  overhead in general, improving the balance  between  the  number  of  messages  and  the  packet  size  as  well  as studying the  optimal  distribution  of  the  model  subdomains  according  to  the  computing  resources  and  network  topology. 

=== Implementation

The implementation will start with the classic scalability tests and performance analysis using state-of-the-art performance tools. From this information, an assessment will be done and we will propose the main directions in which we can work to take more profit from reducing communication's overhead. Then the changes will be performed and another study will evaluate the outcome of the actions and validate if they fulfilled the expectations.

=== Documentation updates



== Preview 



== Tests



== Review