ILOG CPLEX 11.0 User's Manual

If a log file is active when the clones are created, then ILOG CPLEX creates a clone log filefor each clone. The clone log files are named cloneK.log, where K is the index of theclone, ranging from 0 (zero) to the number of threads minus one. Since the clones arecreated at each call to the parallel MIP optimizer and discarded when it exits, the clone logsare opened at each call and closed at each exit. (The clone log files are not removed when theclones themselves are discarded.)The clone logs contain information normally recorded in the ordinary log file (by default,cplex.log) but inconvenient to send through the normal log channel. The informationlikely to be of most interest to you are special messages, such as error messages, that resultfrom calls to the LP optimizers called for the subproblems.Clock Settings and Time MeasurementOn most platforms, ILOG CPLEX offers two ways of measuring time: CPU time andwall-clock time. However, on Microsoft Windows platforms, only wall-clock time isavailable. By default, when ILOG CPLEX is running sequentially, CPU time is reported onplatforms that support it. In contrast, when ILOG CPLEX is running parallel algorithms,wall-clock time is the default on all platforms.On platforms that support both types of clock, you can choose the type of clock by settingthe clocktype parameter to a value different from the default 0 (zero).◆◆In Concert Technology, use the method:●●●IloCplex::setParam(ClockType, i) in the C++ API;IloCplex.setParam(ClockType, i) in the Java API;Cplex.SetParam(ClockType, i) in the .NET API.In the Callable Library, use the routineCPXsetintparam(env, CPX_PARAM_CLOCKTYPE, i).◆ Interactive Optimizer, with the command set clocktype i.Replace the i with the value 1(one) to specify CPU time or 2 to specify wall-clock time.500 ILOG CPLEX 11.0 — USER’ S MANUAL