cuopt service resolve conflict with log_file parameter and callbacks

Author: tmckayus

python/cuopt/cuopt/linear_programming/solver/solver.py

@@ -19,7 +19,7 @@
 
 
 @catch_cuopt_exception
-def Solve(data_model, solver_settings=None, log_file=""):
+def Solve(data_model, solver_settings=None):
     """
     Solve the Linear Program passed as input and returns the solution.
 
@@ -92,13 +92,12 @@ def is_mip(var_types):
     return solver_wrapper.Solve(
         data_model,
         solver_settings,
-        log_file,
         mip=is_mip(data_model.get_variable_types()),
     )
 
 
 @catch_cuopt_exception
-def BatchSolve(data_model_list, solver_settings=None, log_file=""):
+def BatchSolve(data_model_list, solver_settings=None):
     """
     Solve the list of Linear Programs passed as input and returns the solutions
     and total solve time.
@@ -174,6 +173,4 @@ def BatchSolve(data_model_list, solver_settings=None, log_file=""):
     if solver_settings is None:
         solver_settings = SolverSettings()
 
-    return solver_wrapper.BatchSolve(
-        data_model_list, solver_settings, log_file
-    )
+    return solver_wrapper.BatchSolve(data_model_list, solver_settings)

python/cuopt/cuopt/linear_programming/solver/solver_wrapper.pyx

@@ -65,7 +65,6 @@ from numba import cuda
 import cudf
 from cudf.core.buffer import as_buffer
 
-from cuopt.linear_programming.solver.solver_parameters import CUOPT_LOG_FILE
 from cuopt.linear_programming.solver_settings.solver_settings import (
     PDLPSolverMode,
     SolverSettings,
@@ -279,7 +278,6 @@ cdef set_data_model_view(DataModel data_model_obj):
 cdef set_solver_setting(
         unique_ptr[solver_settings_t[int, double]]& unique_solver_settings,
         settings,
-        log_file,
         DataModel data_model_obj=None,
         mip=False):
     cdef solver_settings_t[int, double]* c_solver_settings = (
@@ -425,13 +423,6 @@ cdef set_solver_setting(
             settings.get_pdlp_warm_start_data().iterations_since_last_restart # noqa
         )
 
-    # Common to LP and MIP
-
-    c_solver_settings.set_parameter_from_string(
-        CUOPT_LOG_FILE.encode('utf-8'),
-        log_file.encode('utf-8')
-    )
-
 cdef create_solution(unique_ptr[solver_ret_t] sol_ret_ptr,
                      DataModel data_model_obj,
                      is_batch=False):
@@ -670,7 +661,7 @@ cdef create_solution(unique_ptr[solver_ret_t] sol_ret_ptr,
         )
 
 
-def Solve(py_data_model_obj, settings, str log_file, mip=False):
+def Solve(py_data_model_obj, settings, mip=False):
 
     cdef DataModel data_model_obj = <DataModel>py_data_model_obj
     cdef unique_ptr[solver_settings_t[int, double]] unique_solver_settings
@@ -682,7 +673,7 @@ def Solve(py_data_model_obj, settings, str log_file, mip=False):
     )
 
     set_solver_setting(
-        unique_solver_settings, settings, log_file, data_model_obj, mip
+        unique_solver_settings, settings, data_model_obj, mip
     )
     set_data_model_view(data_model_obj)
 
@@ -697,13 +688,13 @@ cdef insert_vector(DataModel data_model_obj,
     data_model_views.push_back(data_model_obj.c_data_model_view.get())
 
 
-def BatchSolve(py_data_model_list, settings, str log_file):
+def BatchSolve(py_data_model_list, settings):
     cdef unique_ptr[solver_settings_t[int, double]] unique_solver_settings
     unique_solver_settings.reset(new solver_settings_t[int, double]())
 
     if settings.get_pdlp_warm_start_data() is not None:  # noqa
         raise Exception("Cannot use warmstart data with Batch Solve")
-    set_solver_setting(unique_solver_settings, settings, log_file)
+    set_solver_setting(unique_solver_settings, settings)
 
     cdef vector[data_model_view_t[int, double] *] data_model_views
 

python/cuopt_server/cuopt_server/utils/linear_programming/solver.py

@@ -415,7 +415,7 @@ def get_solver_exception_type(status, message):
         return RuntimeError(msg)
 
 
-def solve(LP_data, reqId, intermediate_sender, warmstart_data, log_file):
+def solve(LP_data, reqId, intermediate_sender, warmstart_data):
     notes = []
 
     def get_if_attribute_is_valid_else_none(attr):
@@ -546,7 +546,7 @@ def create_solution(sol):
             solver_settings.set_mip_callback(callback)
             solve_begin_time = time.time()
             sol = linear_programming.Solve(
-                data_model, solver_settings=solver_settings, log_file=log_file
+                data_model, solver_settings=solver_settings
             )
             total_solve_time = time.time() - solve_begin_time
 

python/cuopt_server/cuopt_server/utils/solver.py

@@ -103,10 +103,18 @@ def solve_LP_sync(
             log_fname = "log_" + reqId
             log_file = os.path.join(log_dir, log_fname)
             logging.info(f"Writing logs to {log_file}")
+            # We have to potentially overwrite the user log_file
+            # value here since we are running in the service and using
+            # web callbacks. The user can not use callbacks if they
+            # want explicit control over the log file.
+            LP_data.solver_config.log_file = log_file
         else:
             log_file = ""
         notes, addl_warnings, res, total_solve_time = LP_solve(
-            LP_data, reqId, intermediate_sender, warmstart_data, log_file
+            LP_data,
+            reqId,
+            intermediate_sender,
+            warmstart_data,
         )
         warnings.extend(addl_warnings)
     else:

python/cuopt_server/cuopt_server/webserver.py

@@ -957,7 +957,9 @@ async def postrequest(
     ),
     solver_logs: Optional[bool] = Query(
         default=False,
-        description="If set to True, MIP problems will produce detailed solver logs that can be retrieved from /cuopt/log/{id}",  # noqa
+        description="If set to True, MIP problems will produce detailed solver logs that can be retrieved from /cuopt/log/{id}. "  # noqa
+        "The solver_config.log_file value will be set to log_{id} overriding any user value set. If a user wants logs generated "  # noqa
+        "on the server with a user-defined name, then do not use the callback mechanism and simply set solver_config.log_file as desired.",  # noqa
     ),
     cuopt_data_file: str = Header(
         default=None,