feat: add workflow parallel depth limit configuration (#11460)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: zxhlyh <jasonapring2015@outlook.com>

api/.env.example

@@ -399,6 +399,7 @@ INDEXING_MAX_SEGMENTATION_TOKENS_LENGTH=4000
 WORKFLOW_MAX_EXECUTION_STEPS=500
 WORKFLOW_MAX_EXECUTION_TIME=1200
 WORKFLOW_CALL_MAX_DEPTH=5
+WORKFLOW_PARALLEL_DEPTH_LIMIT=3
 MAX_VARIABLE_SIZE=204800
 
 # App configuration

api/configs/feature/__init__.py

@@ -433,6 +433,11 @@ class WorkflowConfig(BaseSettings):
         default=5,
     )
 
+    WORKFLOW_PARALLEL_DEPTH_LIMIT: PositiveInt = Field(
+        description="Maximum allowed depth for nested parallel executions",
+        default=3,
+    )
+
     MAX_VARIABLE_SIZE: PositiveInt = Field(
         description="Maximum size in bytes for a single variable in workflows. Default to 200 KB.",
         default=200 * 1024,

api/controllers/console/app/workflow.py

@@ -6,6 +6,7 @@ from flask_restful import Resource, marshal_with, reqparse
 from werkzeug.exceptions import Forbidden, InternalServerError, NotFound
 
 import services
+from configs import dify_config
 from controllers.console import api
 from controllers.console.app.error import ConversationCompletedError, DraftWorkflowNotExist, DraftWorkflowNotSync
 from controllers.console.app.wraps import get_app_model
@@ -426,7 +427,21 @@ class ConvertToWorkflowApi(Resource):
         }
 
 
+class WorkflowConfigApi(Resource):
+    """Resource for workflow configuration."""
+
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.ADVANCED_CHAT, AppMode.WORKFLOW])
+    def get(self, app_model: App):
+        return {
+            "parallel_depth_limit": dify_config.WORKFLOW_PARALLEL_DEPTH_LIMIT,
+        }
+
+
 api.add_resource(DraftWorkflowApi, "/apps/<uuid:app_id>/workflows/draft")
+api.add_resource(WorkflowConfigApi, "/apps/<uuid:app_id>/workflows/draft/config")
 api.add_resource(AdvancedChatDraftWorkflowRunApi, "/apps/<uuid:app_id>/advanced-chat/workflows/draft/run")
 api.add_resource(DraftWorkflowRunApi, "/apps/<uuid:app_id>/workflows/draft/run")
 api.add_resource(WorkflowTaskStopApi, "/apps/<uuid:app_id>/workflow-runs/tasks/<string:task_id>/stop")

api/core/workflow/graph_engine/entities/graph.py

@@ -4,6 +4,7 @@ from typing import Any, Optional, cast
 
 from pydantic import BaseModel, Field
 
+from configs import dify_config
 from core.workflow.graph_engine.entities.run_condition import RunCondition
 from core.workflow.nodes import NodeType
 from core.workflow.nodes.answer.answer_stream_generate_router import AnswerStreamGeneratorRouter
@@ -170,7 +171,9 @@ class Graph(BaseModel):
         for parallel in parallel_mapping.values():
             if parallel.parent_parallel_id:
                 cls._check_exceed_parallel_limit(
-                    parallel_mapping=parallel_mapping, level_limit=3, parent_parallel_id=parallel.parent_parallel_id
+                    parallel_mapping=parallel_mapping,
+                    level_limit=dify_config.WORKFLOW_PARALLEL_DEPTH_LIMIT,
+                    parent_parallel_id=parallel.parent_parallel_id,
                 )
 
         # init answer stream generate routes

api/tests/unit_tests/configs/test_dify_config.py

@@ -59,6 +59,8 @@ def test_dify_config(example_env_file):
     # annotated field with configured value
     assert config.HTTP_REQUEST_MAX_WRITE_TIMEOUT == 30
 
+    assert config.WORKFLOW_PARALLEL_DEPTH_LIMIT == 3
+
 
 # NOTE: If there is a `.env` file in your Workspace, this test might not succeed as expected.
 # This is due to `pymilvus` loading all the variables from the `.env` file into `os.environ`.