Re: crash with more than 96 processors (v2.7b1)

From: Grace Brannigan (grace_at_vitae.cmm.upenn.edu)
Date: Fri May 01 2009 - 09:48:09 CDT

Hi Chris,

The closest distance is between the two oxygens of the water : 1.69A. There
was no clash in the beginning of the simulation (they started at 2.73 A).
However, the system is shrinking as a result of the Langevin piston, but
should that be dependent on the number of nodes?

Timestep of 1.0 results in a crash as well with the same waters, after more
steps but about the same amount of fs.

Changing the hgroupCutoff to 2.5 actually made the simulation crash at step
120 instead 140.

Increasing the margin to 1.0 doesn't change anything.

Ideas?

-Grace

On Thu, Apr 30, 2009 at 8:41 PM, Chris Harrison <char_at_ks.uiuc.edu> wrote:

> Grace,
>
> A few questions:
> You say "close," can you give the distance between the closest atoms in
> Angstroms?
>
> Are the two closest atoms hydrogens by chance? If so, could you try a
> restart from something fairly close to step 140, using timestep of 1.0.
>
> Also, is there a specific reason for the hgroupCutoff value 2.8? If not,
> could you try reducing that to 2.5 and see if that makes a difference?
>
> If neither of these make a difference, could you increase the margin to 0.5
> or 1.0 and test that?
>
>
> C.
>
>
> --
> Chris Harrison, Ph.D.
> Theoretical and Computational Biophysics Group
> NIH Resource for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave., Urbana, IL 61801
>
> char_at_ks.uiuc.edu Voice: 217-244-1733
> http://www.ks.uiuc.edu/~char <http://www.ks.uiuc.edu/%7Echar>
> Fax: 217-244-6078
>
>
>
> On Thu, Apr 30, 2009 at 2:49 PM, Grace Brannigan <gracebrannigan_at_gmail.com
> > wrote:
>
>> Hi Chris,
>>
>> I did as you suggested. For the system run on 128 nodes, the energies
>> right before the crash at step 140 are:
>>
>> ENERGY: 139 368.4760 1082.8205 1324.6014
>> 45.3948 -251964.9404 25326.2532 496.9566
>> 0.0000 6871.6446 -216448.7934 57.8604 -216443.9396
>> -216448.2858 57.8604 -228.2303 -274.6782
>> 587038.2456 -228.2303 -274.6782
>>
>> ENERGY: 140 366.8165 1084.7263 1325.5485
>> 46.3538 -251992.5581 26939.8959 495.4494 0.0000
>> 99999999.9999 99999999.9999 99999999.9999 99999999.9999
>> nan -99999999.9999 -99999999.9999 -99999999.9999 586888.6700
>> -99999999.9999 -99999999.9999
>>
>> For comparison, the energies at the same step on 96 nodes are
>>
>> ENERGY: 139 358.1118 1087.0480 1328.9915
>> 46.5093 -252345.2854 25274.9919 497.1248
>> 0.0000 6527.0026 -217225.5054 54.9585 -217220.9702
>> -217225.8113 54.9585 -302.9743 -347.3116
>> 587059.0631 -302.9743 -347.3116
>>
>> Looking at the dcd file, there are two water molecules (the ones with
>> infinite velocity at step 140) that are close right before the crash, but
>> not overlapping.
>>
>> -Grace
>>
>>
>>
>>
>> On Tue, Apr 28, 2009 at 7:30 PM, Chris Harrison <char_at_ks.uiuc.edu> wrote:
>>
>>> Could you please set the following parameters as indicated and rerun the
>>> 128 proc job on either cluster:
>>>
>>> dcdfreq 1
>>> outputEnergies 1
>>>
>>> The idea is to isolate, via looking at the components of the energy in
>>> the log file and the changes in the structure from the dcd file, anything
>>> "physical" in your simulation that may be "blowing up." If there is
>>> something physical "blowing up", you will need to do two things:
>>>
>>> 1. examine the energy components from the log file at the corresponding
>>> log file. The component that shoots up should correspond to the physical
>>> interaction responsible for the "physical blowing up."
>>>
>>> 2. You should probably also compare the dynamics and energy component
>>> trends to the 96 processor simulation to examine their similarity and assess
>>> how reasonable it is that MTS yielded dynamics different enough to crash one
>>> sim w/ X # of procs vs one sim w/ Y # of procs. Basically are the
>>> simulations comparable up to a point and at what point do they seriously
>>> diverge quickly leading to a crash ... in which regime of MTS (based on your
>>> config parameters) does this seem to fit. We need to figure out if we're
>>> looking at a difference in dynamics or if there's a "bug" yielding a
>>> "physically realistic blow up" that only shows up during a parallel process
>>> like patch migration/reduction, etc when using 128 as opposed to 96 procs.
>>>
>>> If there is nothing physical that is blowing up and the simulation is
>>> really just spontaneously crashing on both architectures using 128 procs
>>> then we'll have to dig deeper and consider running your simulation with
>>> debug flags and trace things to the source of the crash.
>>>
>>>
>>> C.
>>>
>>>
>>> --
>>> Chris Harrison, Ph.D.
>>> Theoretical and Computational Biophysics Group
>>> NIH Resource for Macromolecular Modeling and Bioinformatics
>>> Beckman Institute for Advanced Science and Technology
>>> University of Illinois, 405 N. Mathews Ave., Urbana, IL 61801
>>>
>>> char_at_ks.uiuc.edu Voice: 217-244-1733
>>> http://www.ks.uiuc.edu/~char <http://www.ks.uiuc.edu/%7Echar>
>>> Fax: 217-244-6078
>>>
>>>
>>>
>>> On Tue, Apr 28, 2009 at 5:36 PM, Grace Brannigan <
>>> grace_at_vitae.cmm.upenn.edu> wrote:
>>>
>>>> Hi Chris,
>>>>
>>>> The 128 processor job dies immediately, while the 96 processor job can
>>>> go on for forever (or at least 4ns).
>>>>
>>>> Our cluster is a dual quadcore Xeon E5430 with infiniband interconnect,
>>>> and yes, it dies at 128 cores on both clusters.
>>>>
>>>> -Grace
>>>>
>>>>
>>>> On Tue, Apr 28, 2009 at 5:50 PM, Chris Harrison <char_at_ks.uiuc.edu>wrote:
>>>>
>>>>> Grace,
>>>>>
>>>>> You say your cluster, I'm assuming this isn't an XT5. ;)
>>>>>
>>>>> Can you provide some details on your cluster and clarify if you mean
>>>>> 128 procs on both clusters, irrespective of architecture?
>>>>>
>>>>> Also, you have confirmed that using the lower # of procs you can exceed
>>>>> the timestep at which the "128 proc" job dies, correct?
>>>>>
>>>>>
>>>>> C.
>>>>>
>>>>>
>>>>> --
>>>>> Chris Harrison, Ph.D.
>>>>> Theoretical and Computational Biophysics Group
>>>>> NIH Resource for Macromolecular Modeling and Bioinformatics
>>>>> Beckman Institute for Advanced Science and Technology
>>>>> University of Illinois, 405 N. Mathews Ave., Urbana, IL 61801
>>>>>
>>>>> char_at_ks.uiuc.edu Voice: 217-244-1733
>>>>> http://www.ks.uiuc.edu/~char <http://www.ks.uiuc.edu/%7Echar>
>>>>> Fax: 217-244-6078
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Tue, Apr 28, 2009 at 2:16 PM, Grace Brannigan <
>>>>> grace_at_vitae.cmm.upenn.edu> wrote:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I have been simulating a protein in a truncated octahedral water
>>>>>> box(~90k atoms) using NAMD2.7b1. On both our local cluster and Jim's kraken
>>>>>> build, the job runs fine if I use up to 96 processors. With 128 the job
>>>>>> crashes after an error message, which is not consistent and can either be
>>>>>> "bad global exclusion count", atoms with nan velocities, or just a seg
>>>>>> fault. I haven't had any problems like this with the other jobs I've been
>>>>>> running using v2.7b1, which, admittedly, have more conventional geometries.
>>>>>> My conf file is below - any ideas?
>>>>>>
>>>>>> -Grace
>>>>>>
>>>>>>
>>>>>> **********************
>>>>>>
>>>>>> # FILENAMES
>>>>>> set outName [file rootname [file tail [info script]]]
>>>>>> #set inFleNum [expr [scan [string range $outName end-1 end]
>>>>>> "%d"] - 1]
>>>>>> #set inName [format "%s%02u" [string range $outName 0
>>>>>> end-2] $inFileNum]
>>>>>> #set inName ionized
>>>>>> set inName min01
>>>>>> set homedir ../../..
>>>>>> set sourcepath ../../solvate_and_ionize/riso
>>>>>>
>>>>>> timestep 2.0
>>>>>>
>>>>>> structure $sourcepath/ionized.psf
>>>>>> parameters $homedir/toppar/par_all27_prot_lipid.prm
>>>>>> parameters $homedir/toppar/par_isoflurane_RS.inp
>>>>>> paraTypeCharmm on
>>>>>>
>>>>>> set temp 300.0
>>>>>> #temperature $temp
>>>>>> # RESTRAINTS
>>>>>>
>>>>>> constraints on
>>>>>> consref $sourcepath/constraints.pdb
>>>>>> conskfile $sourcepath/constraints.pdb
>>>>>> conskcol O
>>>>>>
>>>>>> # INPUT
>>>>>>
>>>>>> coordinates $sourcepath/ionized.pdb
>>>>>> extendedsystem $inName.xsc
>>>>>> binvelocities $inName.vel
>>>>>> bincoordinates $inName.coor
>>>>>> #cellBasisVector1 108 0 0
>>>>>> #cellBasisVector2 0 108 0
>>>>>> #cellBasisVector3 54 54 54
>>>>>>
>>>>>> # OUTPUT
>>>>>>
>>>>>> outputenergies 500
>>>>>> outputtiming 500
>>>>>> outputpressure 500
>>>>>> binaryoutput yes
>>>>>> outputname [format "%so" $outName]
>>>>>> restartname $outName
>>>>>> restartfreq 500
>>>>>> binaryrestart yes
>>>>>>
>>>>>> XSTFreq 500
>>>>>> COMmotion no
>>>>>>
>>>>>> # DCD TRAJECTORY
>>>>>>
>>>>>> DCDfile $outName.dcd
>>>>>> DCDfreq 5000
>>>>>>
>>>>>> # CUT-OFFs
>>>>>>
>>>>>> splitpatch hydrogen
>>>>>> hgroupcutoff 2.8
>>>>>> stepspercycle 20
>>>>>> switching on
>>>>>> switchdist 10.0
>>>>>> cutoff 12.0
>>>>>> pairlistdist 13.0
>>>>>>
>>>>>> #margin 1.0
>>>>>>
>>>>>> wrapWater no
>>>>>>
>>>>>> # CONSTANT-T
>>>>>>
>>>>>> langevin on
>>>>>> langevinTemp $temp
>>>>>> langevinDamping 0.1
>>>>>>
>>>>>> # CONSTANT-P
>>>>>>
>>>>>> useFlexibleCell no
>>>>>> useConstantRatio no
>>>>>> useGroupPressure yes
>>>>>>
>>>>>> langevinPiston on
>>>>>> langevinPistonTarget 1
>>>>>> langevinPistonPeriod 200
>>>>>> langevinPistonDecay 100
>>>>>> langevinPistonTemp $temp
>>>>>>
>>>>>> # PME
>>>>>>
>>>>>> PME yes
>>>>>> PMETolerance 10e-6
>>>>>> PMEInterpOrder 4
>>>>>>
>>>>>> PMEGridSizeX 120
>>>>>> PMEGridSizeY 120
>>>>>> PMEGridSizeZ 96
>>>>>>
>>>>>> # MULTIPLE TIME-STEP
>>>>>>
>>>>>> fullelectfrequency 2
>>>>>> nonbondedfreq 1
>>>>>>
>>>>>> # SHAKE/RATTLE
>>>>>>
>>>>>> rigidBonds all
>>>>>>
>>>>>> # 1-4's
>>>>>>
>>>>>> exclude scaled1-4
>>>>>> 1-4scaling 1.0
>>>>>>
>>>>>> constraintscaling 1.0
>>>>>> run 250000
>>>>>> constraintscaling 0.0
>>>>>> 1250000
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>>
>

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