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Re^3: More advanced problem p2p fails

Alex Granovsky
gran@classic.chem.msu.su


Hi,

sorry for the delayed reply.

It your HPC solution is based on Win2K8 R2, (note not R1),
you may be affected by the same core parking problem, as Windows 7 users.

See http://classic.chem.msu.su/cgi-bin/ceilidh.exe/gran/gamess/forum/?C34df668afbHW-7361-1269-00.htm for details and possible workaround. Note we do not test it under Win2K8 R2...

Second, just adding

 $p2p p2p=.t. $end

does not automatically enables dynamic load balancing. Use at least

 $p2p p2p=.t. dlb=.t. $end

or

 $p2p p2p=.t. xdlb=.t. $end

You can also give a try to more advanced communication-related p2p options like:

 $p2p 
     p2p=.t. xdlb=.t. 

! to bind to interface 
     bind=.t. 
! to use non-blocked I/O for DLB 
     blkdlb=0 
! to use polling instead of blocking waiting for DLB event
     nbiolb=1 
! to set larger TCP window sizes (in Kbytes) 
! for send and receive buffers.
     sndbuf=256 rcvbuf=256
 $end                          

Finally, use "-daf 2" command line option to reduce communication's
overhead.

regards,
Alex Granovsky

On Wed Mar 24 '10 3:09pm, Vyacheslav wrote
------------------------------------------
>Hi,
>we exchange p2p.dll and now in output I see always (regardless of node number in run):

>Loading P2P interface library... loaded successfully (version 1.C).
>Initializing P2P interface... topology done.

>However time of calculation decreases (relatively calculation on one node) only for run on two nodes. For three and more nodes time sharply increases. Loading of network, CPUs, HDDs are very low.
>It is observed for different inputs, including one for МР2. The number of processes is specified in a output correctly in all cases.

>What is the following step?

>-------------------------------------------------------
>On Tue Mar 23 '10 9:54pm, Alex Granovsky wrote
>----------------------------------------------
>>Hi,

>>First, you are using shared memory version of p2p library
>>(that is currently version 1.9, while TCP/IP version of p2p
>>interface is version 1.C or 1.D). Naturally, the shared memory
>>version will not work across multiple nodes, and you need to
>>use the generic TCP/IP version of p2p. Note, you need to
>>disable Windows firewall on all compute nodes.

>>Regards,
>>Alex Granovsky
>


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