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thanks<br><br>I have installed Blis-0.9 and try to run it on a cluster with MPICH2.<br>I am using 2 processes to run the benchmark bell5.mps, which is a mixed <br>integer linear programming. <br><br>ftp://ftp.caam.rice.edu/pub/people/bixby/miplib/miplib3/bell5<br><br>I got error :<br><br>--------------------------------------<br>mpiexec -np 2 blis -par p0548.mps<br>Reading in ALPS parameters ...<br>Reading in BLIS parameters ...<br>Alps0110I ALPS version 1.0 (Parallel, MPI)<br>Alps0050I Launched 2 processes<br>Bcps0001I BiCePS version 0.9<br>Blis0001I BLIS version 0.9<br>Blis0020I WARNING: The Problem does not have integer variables<br>Fatal error in MPI_Barrier: Other MPI error, error stack:<br>MPI_Barrier(406)..........................: MPI_Barrier(MPI_COMM_WORLD) <br><br>failed<br>MPIR_Barrier(77)..........................:<br>MPIC_Sendrecv(123)........................:<br>MPIC_Wait(270)............................:<br>MPIDI_CH3i_Progress_wait(215).............: an error occurred while <br><br>handling an event returned by MPIDU_Sock_Wait()<br>MPIDI_CH3I_Progress_handle_sock_event(420):<br>MPIDU_Socki_handle_read(637)..............: connection failure <br><br>(set=0,sock=1,errno=104:Connection reset by peer)[cli_1]: aborting job:<br>Fatal error in MPI_Barrier: Other MPI error, error stack:<br>MPI_Barrier(406)..........................: MPI_Barrier(MPI_COMM_WORLD) <br><br>failed<br>MPIR_Barrier(77)..........................:<br>MPIC_Sendrecv(123)........................:<br>MPIC_Wait(270)............................:<br>MPIDI_CH3i_Progress_wait(215).............: an error occurred while <br><br>handling an event returned by MPIDU_Sock_Wait()<br>MPIDI_CH3I_Progress_handle_sock_event(420):<br>MPIDU_Socki_handle_read(637)..............: connection failure <br><br>(set=0,sock=1,errno=104:Connection reset by peer)<br>rank 0 in job 7 mountain.ece.college.edu_57166 caused collective abort <br><br>of all ranks<br> exit status of rank 0: killed by signal 11<br><br>--------------------------------------<br>Why Blis say that he Problem does not have integer variables ?<br>bell5 has 58 integer variables. <br><br>Any help is appreciated. <br><br>Jack<br>April 22 2009<br><br>> Date: Wed, 22 Apr 2009 10:16:48 +0200<br>> From: achterberg@zib.de<br>> To: dtustudy68@hotmail.com<br>> CC: coin-discuss@list.coin-or.org<br>> Subject: Re: [Coin-discuss] SYMPHONY speedup<br>> <br>> Hi Jack,<br>> <br>> for MILP, your question cannot be answered (LP is a different story). Parallel speedup and<br>> performance difference accross different solvers depend on the model.<br>> <br>> For example, there are models that can be solved by solver A in less than a second but<br>> that take forever by another solver B, just because solver B is lacking the important<br>> feature (like a cutting plane or a presolving reduction) to solve this particular model.<br>> And there may be other models for which the situation is reversed. Finally, there are<br>> models that can be solved in roughly the same time by all branch-and-cut MILP solvers.<br>> <br>> Overall, my experience is that the algorithmic quality of a solver is usually much more<br>> important than parallelization. This means, that often solvers like CBC, SCIP, Gurobi,<br>> XPress, or CPLEX will be faster than Symphony, even if you use 1000 CPUs for Symphony.<br>> But, as I said, some models do not require the sophisticated machinery that these solvers<br>> provide and parallelize well. In this setting, Symphony can be really great if you have<br>> access to a massively parallel computing environment.<br>> <br>> So, the short answer is: you just need to test it for your models. You cannot say in advance.<br>> <br>> <br>> Cheers,<br>> <br>> Tobias<br>> <br>> Jack Bryan wrote:<br>> > Hi ,<br>> > <br>> > I am a new user of SYMPHONY .<br>> > <br>> > I need to use it to solve very large mixed integer linear programming <br>> > models.<br>> > <br>> > So, I need to use PVM for SYMPHONY .<br>> > <br>> > But, I do not know how much speed up I can get from the parallel SYMPHONY ?<br>> > <br>> > For example, if it takes 100 seconds to solve a MILP model in CPLEX, how<br>> > long to solve it in SYMPHONY ?<br>> > <br>> > <br>> > thanks<br>> > <br>> > Jack<br>> > <br>> > April 21 2009<br>> > <br>> > ------------------------------------------------------------------------<br>> > Windows Live™ Hotmail®:…more than just e-mail. Check it out.<br>> > <http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_HM_more_042009><br>> > <br>> > <br>> > ------------------------------------------------------------------------<br>> > <br>> > _______________________________________________<br>> > Coin-discuss mailing list<br>> > Coin-discuss@list.coin-or.org<br>> > http://list.coin-or.org/mailman/listinfo/coin-discuss<br><br /><hr />Rediscover Hotmail®: Get quick friend updates right in your inbox. <a href='http://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Updates2_042009' target='_new'>Check it out.</a></body>
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