> On Nov 1, 2017, at 1:13 PM, Mark Adams <mfad...@lbl.gov> wrote: > > Yea, I don't understand the linear solve error: > > -ts_monitor -ts_type beuler -pc_type lu -pc_factor_mat_solver_package mumps > -ksp_type preonly -snes_monitor -snes_rtol 1.e-10 -snes_stol 1.e-10 > -snes_converged_reason -snes_atol 1.e-18 -snes_converged_reason > > Maybe mumps? > > On Wed, Nov 1, 2017 at 2:02 PM, Jed Brown <j...@jedbrown.org> wrote: > Mark Adams <mfad...@lbl.gov> writes: > > > On Wed, Nov 1, 2017 at 1:46 PM, Jed Brown <j...@jedbrown.org> wrote: > > > >> Mark Adams <mfad...@lbl.gov> writes: > >> > >> > I have added some code in a TS post step method to look at the number of > >> > nonlinear iterations and cut the time step if it took too many SNES > >> > iterations. That helped but now I want to go one step further and > >> recover > >> > from a failed time step (see appended error message). > >> > > >> > How can/should I recover from a SNES failure inside of TS? I could just > >> put > >> > TSSolve in a loop and if TS failed because of the solver, then reduce the > >> > time step and try to recover the state, and try again.
This is absolute nonsense. No way should you or do you need to do this. TS can/is suppose to handle failures in the solver cleanly. We need a reproducible result where it does not handle it correctly and then we fix the problem > >> > > >> > Thoughts? > >> > > >> > Thanks, > >> > Mark > >> > > >> > Note, this is a direct solver and the linear solver is diverging? I've > >> > seen the same thing with the maximum its in SNES and failed linesearch. > >> > > >> > 23 TS dt 0.0025 time 0.1025 > >> > 0 SNES Function norm 9.997473571601e+04 > >> > 1 SNES Function norm 2.295851692533e-01 > >> > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE > >> iterations 1 > >> > [0]PETSC ERROR: --------------------- Error Message > >> > -------------------------------------------------------------- > >> > [0]PETSC ERROR: > >> > [0]PETSC ERROR: TSStep has failed due to DIVERGED_NONLINEAR_SOLVE, > >> increase > >> > -ts_max_snes_failures or make negative to attempt recovery > >> > >> Did you increase -ts_max_snes_failures (TSSetMaxSNESFailures)? > >> > > > > Ah, read the error message :) with a negative value I get this. > > > > TS can not, or is not going to try, to reconstruct my state and reduce the > > time step. So I think I need to do this myself. > > I don't understand. Why is the linear solve diverging > (-ksp_converged_reason)? What TS are you using? > > > I guess just making loop and testing in the TSConvergedReason, is the way > > to go. We already do something like this for mesh adpativity. > > > > Thanks, > > > > 23 TS dt 0.0025 time 0.1025 > > 0 SNES Function norm 9.997473571601e+04 > > 1 SNES Function norm 2.295851692533e-01 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 1 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > 0 SNES Function norm 9.997473571601e+04 > > Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 > > [0]PETSC ERROR: --------------------- Error Message > > -------------------------------------------------------------- > > [0]PETSC ERROR: > > [0]PETSC ERROR: TSStep has failed due to DIVERGED_STEP_REJECTED > > [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for > > trouble shooting. > > [0]PETSC ERROR: Petsc Development GIT revision: v3.8-53-ga2d93b2d43 GIT > > Date: 2017-10-09 12:56:49 -0400 > > [0]PETSC ERROR: ./ex48 on a arch-macosx-gnu-O named MarksMac-5.local by > > markadams Wed Nov 1 13:51:24 2017 > > [0]PETSC ERROR: Configure options --with-cc=clang --with-cc++=clang++ > > COPTFLAGS="-O2 -g -mavx2" CXXOPTFLAGS="-O2 -g -mavx2" FOPTFLAGS="-O2 -g > > -mavx2" --download-mpich=1 --download-parmetis=1 --download-metis=1 > > --download-hypre=1 --download-ml=1 --download-triangle=1 > > --download-ctetgen=1 --download-p4est=1 --download-fftw --download-mumps=1 > > --download-scalapack=1 --with-x=0 --download-superlu_dist > > --download-superlu --download-ctetgen --with-debugging=0 --download-hdf5=1 > > PETSC_ARCH=arch-macosx-gnu-O --download-chaco --with-viewfromoptions=1 > > [0]PETSC ERROR: #1 TSStep() line 4130 in > > /Users/markadams/Codes/petsc/src/ts/interface/ts.c > > [0]PETSC ERROR: #2 TSSolve() line 4374 in > > /Users/markadams/Codes/petsc/src/ts/interface/ts.c > > *********** DIVERGED_STEP_REJECTED ierr=91 reason=-2 > > L_2 Diff: 1.32241e+07 at time 0.1025 > > > > > > > > > >> > >> > [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > >> for > >> > trouble shooting. > >> > [0]PETSC ERROR: Petsc Development GIT revision: v3.8-53-ga2d93b2d43 GIT > >> > Date: 2017-10-09 12:56:49 -0400 > >> > [0]PETSC ERROR: ./ex48 on a arch-macosx-gnu-O named MarksMac-5.local by > >> > markadams Wed Nov 1 13:17:15 2017 > >> > [0]PETSC ERROR: Configure options --with-cc=clang --with-cc++=clang++ > >> > COPTFLAGS="-O2 -g -mavx2" CXXOPTFLAGS="-O2 -g -mavx2" FOPTFLAGS="-O2 -g > >> > -mavx2" --download-mpich=1 --download-parmetis=1 --download-metis=1 > >> > --download-hypre=1 --download-ml=1 --download-triangle=1 > >> > --download-ctetgen=1 --download-p4est=1 --download-fftw > >> --download-mumps=1 > >> > --download-scalapack=1 --with-x=0 --download-superlu_dist > >> > --download-superlu --download-ctetgen --with-debugging=0 > >> --download-hdf5=1 > >> > PETSC_ARCH=arch-macosx-gnu-O --download-chaco --with-viewfromoptions=1 > >> > [0]PETSC ERROR: #1 TSStep() line 4129 in > >> > /Users/markadams/Codes/petsc/src/ts/interface/ts.c > >> > [0]PETSC ERROR: #2 TSSolve() line 4374 in > >> > /Users/markadams/Codes/petsc/src/ts/interface/ts.c > >> > [0]PETSC ERROR: #3 main() line 1161 in /Users/markadams/Codes/mhd/ > >> src/ex48.c > >> >