Fix mlflow param overflow clean (#10071)

* Unify logging with f-strings

* Get limits from MLflow rather than hardcode

* Add a check for parameter length overflow

Also constants are marked as internal

* Don't stop run in on_train_end

This causes bad behaviour when there is a seprarte validation step:
validation gets recorded as separate run.

* Fix style

src/transformers/integrations.py

@@ -707,12 +707,13 @@ class MLflowCallback(TrainerCallback):
     A :class:`~transformers.TrainerCallback` that sends the logs to `MLflow <https://www.mlflow.org/>`__.
     """
 
-    MAX_LOG_SIZE = 100
-
     def __init__(self):
         assert is_mlflow_available(), "MLflowCallback requires mlflow to be installed. Run `pip install mlflow`."
         import mlflow
 
+        self._MAX_PARAM_VAL_LENGTH = mlflow.utils.validation.MAX_PARAM_VAL_LENGTH
+        self._MAX_PARAMS_TAGS_PER_BATCH = mlflow.utils.validation.MAX_PARAMS_TAGS_PER_BATCH
+
         self._initialized = False
         self._log_artifacts = False
         self._ml_flow = mlflow
@@ -738,10 +739,21 @@ class MLflowCallback(TrainerCallback):
             if hasattr(model, "config") and model.config is not None:
                 model_config = model.config.to_dict()
                 combined_dict = {**model_config, **combined_dict}
+            # remove params that are too long for MLflow
+            for name, value in list(combined_dict.items()):
+                # internally, all values are converted to str in MLflow
+                if len(str(value)) > self._MAX_PARAM_VAL_LENGTH:
+                    logger.warning(
+                        f"Trainer is attempting to log a value of "
+                        f'"{value}" for key "{name}" as a parameter. '
+                        f"MLflow's log_param() only accepts values no longer than "
+                        f"250 characters so we dropped this attribute."
+                    )
+                    del combined_dict[name]
             # MLflow cannot log more than 100 values in one go, so we have to split it
             combined_dict_items = list(combined_dict.items())
-            for i in range(0, len(combined_dict_items), MLflowCallback.MAX_LOG_SIZE):
-                self._ml_flow.log_params(dict(combined_dict_items[i : i + MLflowCallback.MAX_LOG_SIZE]))
+            for i in range(0, len(combined_dict_items), self._MAX_PARAMS_TAGS_PER_BATCH):
+                self._ml_flow.log_params(dict(combined_dict_items[i : i + self._MAX_PARAMS_TAGS_PER_BATCH]))
         self._initialized = True
 
     def on_train_begin(self, args, state, control, model=None, **kwargs):
@@ -757,13 +769,10 @@ class MLflowCallback(TrainerCallback):
                     self._ml_flow.log_metric(k, v, step=state.global_step)
                 else:
                     logger.warning(
-                        "Trainer is attempting to log a value of "
-                        '"%s" of type %s for key "%s" as a metric. '
-                        "MLflow's log_metric() only accepts float and "
-                        "int types so we dropped this attribute.",
-                        v,
-                        type(v),
-                        k,
+                        f"Trainer is attempting to log a value of "
+                        f'"{v}" of type {type(v)} for key "{k}" as a metric. '
+                        f"MLflow's log_metric() only accepts float and "
+                        f"int types so we dropped this attribute."
                     )
 
     def on_train_end(self, args, state, control, **kwargs):
@@ -771,13 +780,12 @@ class MLflowCallback(TrainerCallback):
             if self._log_artifacts:
                 logger.info("Logging artifacts. This may take time.")
                 self._ml_flow.log_artifacts(args.output_dir)
-            self._ml_flow.end_run()
 
     def __del__(self):
         # if the previous run is not terminated correctly, the fluent API will
         # not let you start a new run before the previous one is killed
         if self._ml_flow.active_run is not None:
-            self._ml_flow.end_run(status="KILLED")
+            self._ml_flow.end_run()
 
 
 INTEGRATION_TO_CALLBACK = {