Thursday, October 2, 2008

Bug in GAMS/Xpress link

The GAMS/Xpress link can terminate without reason:

**** SOLVER STATUS 4 TERMINATED BY SOLVER
**** MODEL STATUS 8 INTEGER SOLUTION
**** OBJECTIVE VALUE 134400.0000

RESOURCE USAGE, LIMIT 30.379 1000.000
ITERATION COUNT, LIMIT 5515 10000

The listing files does not convey any messages indicating the reason for stopping. We have observed this before, but this bug has not been fixed as of now. If a solver stops it is important to say why. Just simple-mindedly reporting "terminated by solver" makes it very difficult to fix whatever the reason is for the termination of the job.

Note: the log file did not help me either with information why the solve was stopped.