Increase number of threads and set MIPFocus in Gurobi.

erdos-project · Nov 1, 2023 · 6cdee4e · 6cdee4e
1 parent 47d36ae
commit 6cdee4e
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 2 deletions.
diff --git a/schedulers/tetrisched/include/tetrisched/GurobiSolver.hpp b/schedulers/tetrisched/include/tetrisched/GurobiSolver.hpp
@@ -17,6 +17,9 @@ class GurobiSolver : public Solver {
   /// variables.
   std::unordered_map<uint32_t, GRBVar> gurobiVariables;
 
+  /// Set the defaults for parameters on the model.
+  void setDefaultParameters(GRBModel& gurobiModel);
+
   /// Translate the variable to a Gurobi variable.
   GRBVar translateVariable(GRBModel& gurobiModel,
                            const VariablePtr& variable) const;
@@ -25,7 +28,7 @@ class GurobiSolver : public Solver {
   GRBConstr translateConstraint(GRBModel& gurobiModel,
                                 const ConstraintPtr& constraint) const;
 
-  /// Translate teh ObjectiveFunction into a Gurobi expression.
+  /// Translate the ObjectiveFunction into a Gurobi expression.
   GRBLinExpr translateObjectiveFunction(
       GRBModel& gurobiModel,
       const ObjectiveFunctionPtr& objectiveFunction) const;

diff --git a/schedulers/tetrisched/src/GurobiSolver.cpp b/schedulers/tetrisched/src/GurobiSolver.cpp
@@ -1,10 +1,13 @@
 #include "tetrisched/GurobiSolver.hpp"
 
 #include <chrono>
+#include <thread>
 
 namespace tetrisched {
 GurobiSolver::GurobiSolver()
-    : gurobiEnv(new GRBEnv()), gurobiModel(new GRBModel(*gurobiEnv)) {}
+    : gurobiEnv(new GRBEnv()), gurobiModel(new GRBModel(*gurobiEnv)) {
+  setDefaultParameters(*gurobiModel);
+}
 
 SolverModelPtr GurobiSolver::getModel() {
   if (!solverModel) {
@@ -17,6 +20,18 @@ void GurobiSolver::setModel(SolverModelPtr solverModelPtr) {
   solverModel = solverModelPtr;
 }
 
+void GurobiSolver::setDefaultParameters(GRBModel& gurobiModel) {
+  // Set the maximum numer of threads.
+  const auto thread_count = std::thread::hardware_concurrency();
+  gurobiModel.set(GRB_IntParam_Threads, thread_count);
+
+  // Ask Gurobi to aggressively cut the search space.
+  gurobiModel.set(GRB_IntParam_Cuts, 3);
+
+  // Ask Gurobi to find new incumbent solutions rather than prove bounds.
+  gurobiModel.set(GRB_IntParam_MIPFocus, 1);
+}
+
 GRBVar GurobiSolver::translateVariable(GRBModel& gurobiModel,
                                        const VariablePtr& variable) const {
   // Note (Sukrit): Do not use value_or here since the type coercion renders
@@ -129,6 +144,7 @@ void GurobiSolver::translateModel() {
   }
 
   gurobiModel = std::make_unique<GRBModel>(*gurobiEnv);
+  setDefaultParameters(*gurobiModel);
 
   // Generate all the variables and keep a cache of the variable indices
   // to the Gurobi variables.