Changes between Version 24 and Version 25 of UsersGuide


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Timestamp:
Oct 24, 2012 5:35:36 PM (12 years ago)
Author:
Ted Faber
Comment:

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  • UsersGuide

    v24 v25  
    429429The output shows the topology with boxes drawn around the containers that share a physical node:
    430430
    431 
     431[[Image(example6-smaller.png)]]
     432
     433That partitioning is surprising in that {{{lan-1}}} is split into 3 partitions of 6 & 7 nodes rather than 2 parititons of 10.  Similarly {{{lan-2}}} is split into 5 groups of 4 rather than 4 groups of 5.  The packing system is built on the [http://glaros.dtc.umn.edu/gkhome/metis/metis/overview metis] graph paritioning software.  Metis takes a graph and a number of partitions and finds the most balanced partitioning that has roughly equal node counts in each partition as well as low inter-partition communication costs.  The containers system calls metis with increasing numbers of paritions until a partitioning is found that meets the packing factor limits.
     434
     435When the system attempts to pack {{{lan-1}}} into 2 partitions, metis balances the node counts and the communications costs to produce a partition with 9 containers in one machine and 11 on the other.  That partitioning does not meet the 10 node limit, so it tries again with 3 partitions and succeeds.
     436
     437There are two ways to fit our topology onto fewer nodes.  The first is to put slightly more slop into the packing factors:
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     439
     440|| __Pass__ || __Packing Factor__ ||
     441|| 0 || 1||
     442|| 1 || 20 ||
     443|| 2 || 11 ||
     444|| 3 || 6 ||
     445
     446{{{
     447users:~$ /share/containers/containerize.py --pass-pack 0:1,1:20,2:11,3:6 DeterTest example6 ~/example6.tcl
     448Containerized experiment DeterTest/example6 successfully created!
     449Access it via http://www.isi.deterlab.net//showexp.php3?pid=DeterTest&eid=example6
     450}}}
    432451
    433452== Further Reading ==