Function GMP::SolverSession::GetNodeNumber(solverSession)


The function GMP::SolverSession::GetNodeNumber returns the number of the current node during MIP optimization from within a node callback.

     solverSession   ! (input) a solver session



An element in the set AllSolverSessions.

Return Value

The number of the node for which the callback is called. It returns -1 if this function is not called inside a solver callback, or if it is not supported by the solver.


  • This function has only meaning for solver sessions belonging to a GMP with type MIP, MIQP or MIQCP.

  • This function can only be used inside a branch, candidate, cut or heuristic callback.

  • This function is only supported by CPLEX.

  • The root node in a branch-and-bound tree gets number 0.