Thanks. What stack do you mean here? -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mike Heffner Sent: Saturday, October 25, 2008 2:48 AM To: MPI 3.0 Fault Tolerance and Dynamic Process Control working Group Subject: Re: [Mpi3-ft] system-level C/R requirements Supalov, Alexander wrote:

Thanks. I think the word "how" below is decisive.

The definition of MPI_Init and MPI_Finalize do not say "how" processes are created, and still, they work. Likewise, as soon as we can define the expected outcome of the proposed calls, we can offload the "how" to the system - in this case, the CR system.

Now we come to the expected outcome. Imagine we guarantee that there's no MPI communication between the PREPARE and RESTORE calls, and no messages stuck in the wire or in the buffers. What can be stored in the system memory covered by CR will be stored there. The rest will be restored by the RESTORE call once it gets control over this memory image back. This may include reinitialization of the networking hardware, reestablishment of connections, reopening of the files, etc.

What other guarantees do CR people want?

If the stack supported these calls asynchronously during MPI communication -- either from a signal handler or from a second thread -- then I think that definition would go a fair way towards what would be required. Mike -- Mike Heffner <[email protected]> Librato, Inc. Blacksburg, VA USA Voice: (540) 443-3500 #603 _______________________________________________ mpi3-ft mailing list [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-ft --------------------------------------------------------------------- Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen Germany Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer Registergericht: Muenchen HRB 47456 Ust.-IdNr. VAT Registration No.: DE129385895 Citibank Frankfurt (BLZ 502 109 00) 600119052 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.