[mpich-discuss] MPI memory allocation.

Mon Dec 9 13:27:35 CST 2013

Yes, I"m actually need Fault tolerance, and it was the main reason for
choosing MPICH2. I use fault tolerance for unpredictable bugs in the
future. My system should survive partially. But in the regular case I just
need full performance. I"m suspect that I don't use MPI correctly, but on
slow rate everything works fine. The fail caused by increasing rate of
MPI_Isend or increasing data buffer size. I didn't find yet any strong
dependence, only main stream.

Unfortunately I have a complex system which has a number of threads in each
process. Part of the threads use different communicators.

I try to simulate the same MPI behavior in simple stand alone test, but
stand alone test works fine. It shows a full network performance, when I
slow down master (on stand alone test), all slaves are stopped too and are
waiting for master to continue. Can I open any MPICH log to send you the
results?

On Mon, Dec 9, 2013 at 8:10 PM, Pavan Balaji <balaji at mcs.anl.gov> wrote:

>
> Do you actually need Fault Tolerance (one of your previous emails seemed
> to indicate that)?
>
> It sounds like there a bug in either your application or in the MPICH
> stack and you are trying to trace that down, and don’t really care about
> fault tolerance.  Is that a correct assessment?
>
> Do you have a simplified program that reproduces this error, that we can
> try?
>
>   — Pavan
>
> On Dec 9, 2013, at 11:44 AM, Anatoly G <anatolyrishon at gmail.com> wrote:
>
> > No. Hardware is Ok. Master process  allocates memory (check with
> MemoryScape doesn't show any sufficient memory allocation in my code). Then
> network traffic become low, and then Master process crashes w/o saving core
> file. I have unlimited size of core files. The same fail (w/o core) I see
> when I call MPI_Abort, but I don't call it.
> >
> >
> > On Mon, Dec 9, 2013 at 7:28 PM, Wesley Bland <wbland at mcs.anl.gov> wrote:
> > Are you actually seeing hardware failure or is your code just crashing?
> It's odd that one specific process would fail so often in the same way if
> it were a hardware problem.
> >
> > Thanks,
> > Wesley
> >
> > On Dec 9, 2013, at 11:15 AM, Anatoly G <anatolyrishon at gmail.com> wrote:
> >
> >> One more interesting fact. Each time I have a failure, the fails only
> master process, but slaves are still exists together with mpiexec.hydra. I
> thought that slaves should fail too, but slaves are live.
> >>
> >>
> >> On Mon, Dec 9, 2013 at 10:30 AM, Anatoly G <anatolyrishon at gmail.com>
> wrote:
> >> I configure MPICH-3.1rc2 build w/o "so" files. But instead of MPICH2 &
> MPICH-3.0.4 I get so files. What should I change in configure line to link
> MPI with my application statically.
> >>
> >>
> >>
> >> On Mon, Dec 9, 2013 at 9:47 AM, Pavan Balaji <balaji at mcs.anl.gov>
> wrote:
> >>
> >> Can you try mpich-3.1rc2?  There were several fixes for this in this
> version and it’ll be good to try that out before we go digging too far into
> this.
> >>
> >>   — Pavan
> >>
> >> On Dec 9, 2013, at 1:46 AM, Anatoly G <anatolyrishon at gmail.com> wrote:
> >>
> >> > With MPICH - 3.0.4 the situation repeated. It looks like MPI
> allocates memory for messages.
> >> > Can you please advice about scenario when MPI or may be TCP under MPI
> allocates memory due to high transfer rate?
> >> >
> >> >
> >> > On Mon, Dec 9, 2013 at 9:32 AM, Anatoly G <anatolyrishon at gmail.com>
> wrote:
> >> > Thank you very much.
> >> > Issend - is not so good, It can't support me Fault tolerance. If
> slave process fails, the master stall.
> >> > I tried mpich-3.0.4 with hydra-3.0.4 but my program which uses MPI
> Fault tolerance doesn't recognize failure of slave process, but recognizes
> failure with MPICH2. May be you can suggest solution?
> >> > I tried to use hydra from MPICH2 but link my program with MPICH3.
> This combination recognizes failures, but I"m not sure that such
> combination is stable enough.
> >> > Can you please advice?
> >> > Anatoly.
> >> >
> >> >
> >> >
> >> > On Sat, Dec 7, 2013 at 5:20 PM, Pavan Balaji <balaji at mcs.anl.gov>
> wrote:
> >> >
> >> > As much as I hate saying this — some people find it easier to think
> of it as “MPICH3”.
> >> >
> >> >   — Pavan
> >> >
> >> > On Dec 7, 2013, at 7:37 AM, Wesley Bland <wbland at mcs.anl.gov> wrote:
> >> >
> >> > > MPICH is just the new version of MPICH2. We renamed it when we went
> past version 3.0.
> >> > >
> >> > > On Dec 7, 2013, at 3:55 AM, Anatoly G <anatolyrishon at gmail.com>
> wrote:
> >> > >
> >> > >> Ok. I"ll try both Issend, and next step to upgrade MPICH to 3.0.4.
> >> > >> I thought before that MPICH & MPICH2 are two different branches,
> when MPICH2 partially supports Fault tolerance, but MPICH not. Now I
> understand, that I was wrong and MPICH2 is just main version of MPICH.
> >> > >>
> >> > >> Thank you very much,
> >> > >> Anatoly.
> >> > >>
> >> > >>
> >> > >>
> >> > >> On Thu, Dec 5, 2013 at 11:01 PM, Rajeev Thakur <thakur at mcs.anl.gov>
> wrote:
> >> > >> The master is receiving too many incoming messages than it can
> match quickly enough with Irecvs. Try using MPI_Issend instead of MPI_Isend.
> >> > >>
> >> > >> Rajeev
> >> > >>
> >> > >> On Dec 5, 2013, at 2:58 AM, Anatoly G <anatolyrishon at gmail.com>
> wrote:
> >> > >>
> >> > >> > Hello.
> >> > >> > I"m using MPICH2 1.5.
> >> > >> > My system contains master and 16 slaves.
> >> > >> > System uses number of communicators.
> >> > >> > The single communicator used for below scenario:
> >> > >> > Each slave sends non-stop 2Kbyte data buffer using MPI_Isend and
> waits using MPI_Wait.
> >> > >> > Master starts with MPI_Irecv to each slave
> >> > >> > Then in endless loop:
> >> > >> > MPI_Waitany and MPI_Irecv on rank returned by MPI_Waitany.
> >> > >> >
> >> > >> > Another communicator used for broadcast communication (commands
> between master + slaves),
> >> > >> > but it's not used in parallel with previous communicator,
> >> > >> > only before or after data transfer.
> >> > >> >
> >> > >> > The system executed on two computers linked by 1Gbit/s Ethernet.
> >> > >> > Master executed on first computer, all slaves on other one.
> >> > >> > Network traffic is ~800Mbit/s.
> >> > >> >
> >> > >> > After 1-2 minutes of execution, master process starts to
> increase it's memory allocation and network traffic becomes low.
> >> > >> > This memory allocation & network traffic slow down continues
> until fail of MPI,
> >> > >> > without core file save.
> >> > >> > My program doesn't allocate memory. Can you please explain this
> behaviour.
> >> > >> > How can I cause MPI to stop sending slaves if Master can't serve
> such traffic, instead of memory allocation and fail?
> >> > >> >
> >> > >> >
> >> > >> > Thank you,
> >> > >> > Anatoly.
> >> > >> >
> >> > >> > P.S.
> >> > >> > On my stand alone test, I simulate similar behaviour, but with
> single thread on each process (master & hosts).
> >> > >> > When I start stand alone test, master stops slaves until it
> completes accumulated data processing and MPI doesn't increase memory
> allocation.
> >> > >> > When Master is free slaves continue to send data.
> >> > >> > _______________________________________________
> >> > >> > discuss mailing list     discuss at mpich.org
> >> > >> > To manage subscription options or unsubscribe:
> >> > >> > https://lists.mpich.org/mailman/listinfo/discuss
> >> > >>
> >> > >> _______________________________________________
> >> > >> discuss mailing list     discuss at mpich.org
> >> > >> To manage subscription options or unsubscribe:
> >> > >> https://lists.mpich.org/mailman/listinfo/discuss
> >> > >>
> >> > >> _______________________________________________
> >> > >> discuss mailing list     discuss at mpich.org
> >> > >> To manage subscription options or unsubscribe:
> >> > >> https://lists.mpich.org/mailman/listinfo/discuss
> >> > > _______________________________________________
> >> > > discuss mailing list     discuss at mpich.org
> >> > > To manage subscription options or unsubscribe:
> >> > > https://lists.mpich.org/mailman/listinfo/discuss
> >> >
> >> > --
> >> > Pavan Balaji
> >> > http://www.mcs.anl.gov/~balaji
> >> >
> >> > _______________________________________________
> >> > discuss mailing list     discuss at mpich.org
> >> > To manage subscription options or unsubscribe:
> >> > https://lists.mpich.org/mailman/listinfo/discuss
> >> >
> >> >
> >> > _______________________________________________
> >> > discuss mailing list     discuss at mpich.org
> >> > To manage subscription options or unsubscribe:
> >> > https://lists.mpich.org/mailman/listinfo/discuss
> >>
> >> --
> >> Pavan Balaji
> >> http://www.mcs.anl.gov/~balaji
> >>
> >> _______________________________________________
> >> discuss mailing list     discuss at mpich.org
> >> To manage subscription options or unsubscribe:
> >> https://lists.mpich.org/mailman/listinfo/discuss
> >>
> >>
> >> _______________________________________________
> >> discuss mailing list     discuss at mpich.org
> >> To manage subscription options or unsubscribe:
> >> https://lists.mpich.org/mailman/listinfo/discuss
> >
> > _______________________________________________
> > discuss mailing list     discuss at mpich.org
> > To manage subscription options or unsubscribe:
> > https://lists.mpich.org/mailman/listinfo/discuss
> >
> > _______________________________________________
> > discuss mailing list     discuss at mpich.org
> > To manage subscription options or unsubscribe:
> > https://lists.mpich.org/mailman/listinfo/discuss
>
> --
> Pavan Balaji
> http://www.mcs.anl.gov/~balaji
>
> _______________________________________________
> discuss mailing list     discuss at mpich.org
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpich.org/pipermail/discuss/attachments/20131209/08196f66/attachment.html>