Address comments

metaflow/client/core.py

@@ -1119,6 +1119,8 @@ class Task(MetaflowObject):
 
     def __init__(self, *args, **kwargs):
         super(Task, self).__init__(*args, **kwargs)
+        # We want to cache metadata dictionary since it's used in many places
+        self._metadata_dict = None
 
     def _iter_filter(self, x):
         # exclude private data artifacts
@@ -1129,20 +1131,15 @@ def _get_task_for_queried_step(self, flow_id, run_id, query_step):
         Returns a Task object corresponding to the queried step.
         If the queried step has several tasks, the first task is returned.
         """
-        # Find any task corresponding to the queried step
-        step = Step(f"{flow_id}/{run_id}/{query_step}", _namespace_check=False)
-        task = next(iter(step.tasks()), None)
-        if task:
-            return task
-        raise MetaflowNotFound(f"No task found for the queried step {query_step}")
+        return Step(f"{flow_id}/{run_id}/{query_step}", _namespace_check=False).task
 
     def _get_metadata_query_vals(
         self,
         flow_id: str,
         run_id: str,
         cur_foreach_stack_len: int,
         steps: List[str],
-        query_type: str,
+        is_ancestor: bool,
     ):
         """
         Returns the field name and field value to be used for querying metadata of successor or ancestor tasks.
@@ -1158,15 +1155,15 @@ def _get_metadata_query_vals(
         steps : List[str]
             List of step names whose tasks will be returned. For static joins, and static splits, we can have
             ancestors and successors across multiple steps.
-        query_type : str
-            Type of query. Can be 'ancestor' or 'successor'.
+        is_ancestor : bool
+            If we are querying for ancestor tasks, set this to True.
         """
         # For each task, we also log additional metadata fields such as foreach-indices and foreach-indices-truncated
         # which help us in querying ancestor and successor tasks.
         #       `foreach-indices`: contains the indices of the foreach stack at the time of task execution.
         #       `foreach-indices-truncated`: contains the indices of the foreach stack at the time of task execution but
         #       truncated by 1
-        # For example, a task thats nested 3 levels deep in a foreach stack may have the following values:
+        # For example, a task that's nested 3 levels deep in a foreach stack may have the following values:
         # foreach-indices = [0, 1, 2]
         # foreach-indices-truncated = [0, 1]
 
@@ -1185,7 +1182,7 @@ def _get_metadata_query_vals(
             # The successor or ancestor tasks belong to the same foreach stack level
             field_name = "foreach-indices"
             field_value = self.metadata_dict.get(field_name)
-        elif query_type == "ancestor":
+        elif is_ancestor:
             if query_foreach_stack_len > cur_foreach_stack_len:
                 # This is a foreach join
                 # Current Task: foreach-indices = [0, 1], foreach-indices-truncated = [0]
@@ -1199,7 +1196,7 @@ def _get_metadata_query_vals(
                 # Current Task: foreach-indices = [0, 1, 2], foreach-indices-truncated = [0, 1]
                 # Ancestor Task: foreach-indices = [0, 1], foreach-indices-truncated = [0]
                 # We will compare the foreach-indices value of ancestor task with the
-                # foreach-indices value of current task
+                # foreach-indices-truncated value of current task
                 field_name = "foreach-indices"
                 field_value = self.metadata_dict.get("foreach-indices-truncated")
         else:
@@ -1221,13 +1218,12 @@ def _get_metadata_query_vals(
                 field_value = self.metadata_dict.get("foreach-indices-truncated")
         return field_name, field_value
 
-    def _get_related_tasks(self, relation_type: str) -> Dict[str, List[str]]:
-        start_time = time.time()
+    def _get_related_tasks(self, is_ancestor: bool) -> Dict[str, List[str]]:
         flow_id, run_id, _, _ = self.path_components
         steps = (
-            self.metadata_dict.get("previous_steps")
-            if relation_type == "ancestor"
-            else self.metadata_dict.get("successor_steps")
+            self.metadata_dict.get("previous-steps")
+            if is_ancestor
+            else self.metadata_dict.get("successor-steps")
         )
 
         if not steps:
@@ -1238,11 +1234,9 @@ def _get_related_tasks(self, relation_type: str) -> Dict[str, List[str]]:
             run_id,
             len(self.metadata_dict.get("foreach-indices", [])),
             steps,
-            relation_type,
+            is_ancestor=is_ancestor,
         )
 
-        cur_time = time.time()
-
         return {
             step: [
                 f"{flow_id}/{run_id}/{step}/{task_id}"
@@ -1266,7 +1260,7 @@ def immediate_ancestors(self) -> Dict[str, List[str]]:
             names of the ancestor steps and the values are the corresponding
             task pathspecs of the ancestors.
         """
-        return self._get_related_tasks("ancestor")
+        return self._get_related_tasks(is_ancestor=True)
 
     @property
     def immediate_successors(self) -> Dict[str, List[str]]:
@@ -1281,7 +1275,7 @@ def immediate_successors(self) -> Dict[str, List[str]]:
             names of the successor steps and the values are the corresponding
             task pathspecs of the successors.
         """
-        return self._get_related_tasks("successor")
+        return self._get_related_tasks(is_ancestor=False)
 
     @property
     def immediate_siblings(self) -> Dict[str, List[str]]:
@@ -1408,9 +1402,12 @@ def metadata_dict(self) -> Dict[str, str]:
             Dictionary mapping metadata name with value
         """
         # use the newest version of each key, hence sorting
-        return {
-            m.name: m.value for m in sorted(self.metadata, key=lambda m: m.created_at)
-        }
+        if self._metadata_dict is None:
+            self._metadata_dict = {
+                m.name: m.value
+                for m in sorted(self.metadata, key=lambda m: m.created_at)
+            }
+        return self._metadata_dict
 
     @property
     def index(self) -> Optional[int]:

metaflow/plugins/metadata_providers/local.py

@@ -247,7 +247,7 @@ def _get_latest_metadata_file(path: str, field_prefix: str) -> tuple:
             # and the artifact files are saved as: <attempt>_artifact__<artifact_name>.json
             # We loop over all the JSON files in the directory and find the latest one
             # that matches the field prefix.
-            json_files = glob.glob(os.path.join(path, "*.json"))
+            json_files = glob.glob(os.path.join(path, f"{field_prefix}*.json"))
             matching_files = []
 
             for file_path in json_files:
@@ -287,8 +287,6 @@ def _read_metadata_value(file_path: str) -> dict:
             # Filter tasks based on metadata
             for task in tasks:
                 task_id = task.get("task_id")
-                if not task_id:
-                    continue
 
                 meta_path = LocalMetadataProvider._get_metadir(
                     flow_id, run_id, query_step, task_id

metaflow/task.py

@@ -781,15 +781,15 @@ def run_step(
                                 tags=metadata_tags,
                             ),
                             MetaDatum(
-                                field="previous_steps",
+                                field="previous-steps",
                                 value=previous_steps,
-                                type="previous_steps",
+                                type="previous-steps",
                                 tags=metadata_tags,
                             ),
                             MetaDatum(
-                                field="successor_steps",
+                                field="successor-steps",
                                 value=successor_steps,
-                                type="successor_steps",
+                                type="successor-steps",
                                 tags=metadata_tags,
                             ),
                         ],