In a multi user environment it can be sometimes helpful/required to audit the GAMS activities. In case there is a single shared GAMS installation (e.g. though a shared file system) and the client machines have write access to a shared location (e.g. a shared and writable subdirectory auditlog in the GAMS system directory) the GAMS Trace Facility (http://www.gamsworld.org/performance/trace.htm) can be used to provide such audit information. In the following example, we assume that the directory auditlog is a user write-able subdirectory of the GAMS system directory.
The admin has to create a starter trace file log.txt in the auditlog directory. The content of the file is as follows
* Trace Record Definition * GamsExit * UserName,ComputerName,InputFileName,JobDate,JobTime,GAMSTotalTime,GamsVersionID
The field names in the last line (UserName, ComputerName, …) are a selection from the list of available names:
LP GamsExecTime ObjectiveValue MIP GamsLineNumber ObjectiveValueEstimate RMIP GamsReturnCode OptionFile NLP GamsStartupTime Platform MCP GamsSymbols SolveLine MPEC GAMSTotalTime SolveNumber RMPEC GamsVersionID SolverCalcTime CNS InputFileName SolverID DNLP JobDate SolverName RMINLP JobTime SolverElapsedTime MINLP JulianDate SolverReadTime QP ModelGenerationTime SolverRealTime QMIP ModelName SolverSignature RQMIP ModelStatus SolverStatus EMP ModelType SolverTime Direction NumberOfDiscreteVariables SolverVersion ETAlg NumberOfDomainViolations SolverWriteTime ETSolve NumberOfEquations User1 ETSolver NumberOfInstructions User2 GamsCloseDownTime NumberOfIterations User3 GamsCompTime NumberOfNodes User4 GamsElapsedTime NumberOfNonlinearNonZeros User5 GamsElements NumberOfNonZeros UserName GamsErrorCount NumberOfVariables ComputerName
Next, we need to instruct GAMS to create a trace record in the log.txt file for every run. The default parameter file gmsprmNT.txt (Windows OS) and gmsprmun.txt (Unix including Mac OS X) allows to provide GAMS with some parameters at startup. In this file we add the trace option:
TRACE=%gams.sysdir%auditlog\log.txt
(replace the back slash \ with a forward slash / for Unix).
Unless overwritten by the user, this trace option will audit every run of GAMS.
