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I have two questions:

  1. What is difference between Hydra and Torque, or to ask in other way: what more Hydra have to offer in compare to Torque? Do I need Hydra at all if I choose to use Torque (+ MAUI)?

  2. Also, what is an advantage of MPICH2 in advance of OpenMPI, since OpenMPI is supporting IB and also have continuously supporting Windows platform? For me it looks like swiss knife. Am I wrong?

Wesley Bland
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user1551228
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1 Answers1

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Torque and Hydra are two completely separate things. Torque is a distributed resource manager that allows execution in batch mode of tasks (jobs) on a network of compute systems. Hydra is part of MPICH and is responsible for launching and controlling processes that are part of the MPI job. The way Torque and Hydra work together is that one submits a job to Torque, which reserves cluster resources and at some point start the job. The mpiexec command in turn uses Hydra to start and control the processes that make the MPI job on the compute nodes provided by Torque.

MPICH2 and Open MPI are both quite mature MPI implementations. While Open MPI supports more connection protocols, there is an InfiniBand-enabled version of MPICH called MVAPICH. MPICH is also basis of several commercial MPI implementations including Intel MPI and Microsoft MPI. While Open MPI has supported Windows for a long time, their Windows maintainer left some time ago and it is unclear if they will continue to support that OS.

Hristo Iliev
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  • Thank you very much for the answer Hristo! What do you suggest me to use? – user1551228 Nov 05 '13 at 13:05
  • Use an MPI implementation that best integrates with your OS and development environment. If you are MS Windows / Visual Studio user, then you might take a look at Microsoft's HPC SDK as it provides some sort of integration with VS. If you use Eclipse with PDT instead, then both Open MPI and MPICH are supported. If you are Unix user, just stick with some supported (by the system administrators) MPI implementation - both Open MPI and MVAPICH deliver good performance. Intel MPI is a nice commercial alternative if you are willing to pay (free license is available for personal use). – Hristo Iliev Nov 05 '13 at 15:50
  • System has to be based on Red Hat, so I will appreciate if you or anyone can give me some advice (at least pros/cons) since I'm novice in this field. – user1551228 Nov 06 '13 at 21:08
  • Your questions suggest that you are building a compute cluster from scratch. If that is the case, why not simply install both MVAPICH and Open MPI and test which one gives better performance with your applications? As to TORQUE, I'm not a big fan of it as I have been predominantly dealing with Sun Grid Engine. Anyway, if you install TORQUE, you should also install MOAB since the scheduler that's built into TORQUE is somewhat dumb. – Hristo Iliev Nov 06 '13 at 21:15
  • Network is Gigabit Ethernet so MVAPICH2 cannot be used. I have an admin role in this project and I'm not really sure which MPI implementation I should choose. – user1551228 Nov 06 '13 at 21:59
  • Go with Open MPI. If your users require some of the new MPI-3.0 functionality, then go with the latest MPICH. – Hristo Iliev Nov 06 '13 at 23:04
  • Hristo, thank you very much! When I was a child, I was big fan of Bulgarian football player Hristo Stoichkov :) Also I noticed that you're at RWTH Aachen - I'm just planning to submit there, so I would appreciate if you can give me your email, so I can ask you few questions. I hope I'm not asking too much. – user1551228 Nov 06 '13 at 23:35