Problem Description
In Dify v1.13.0 self-deployed with Docker, the metadata filtering function of the knowledge retrieval node has the following anomaly:
-
Setting the filter value as a constant: Filters normally, results meet expectations. -
Setting the filter value as a variable (referencing the output of other nodes): Filtering completely fails, results are incorrect.
This function worked perfectly in v1.11.4, but this issue appeared after upgrading to v1.13.0.
Root Cause (Source Code Analysis)
By analyzing the v1.13.0 source code, it’s evident that v1.13.0 refactored the knowledge retrieval node. The code migrated from the old path:
Code
api/core/workflow/nodes/knowledge_retrieval/
to the new path:
Code
api/dify_graph/nodes/knowledge_retrieval/
The problem lies in the _extract_variable_selector_to_variable_mapping method. This method’s purpose is to inform the graph engine “which upstream variables this node depends on,” so the engine can inject variable values into the variable_pool (variable pool) in advance.
However, in the new version of the code, this method only registers query variables, completely omitting variable references within the metadata filtering conditions:
Python
# api/dify_graph/nodes/knowledge_retrieval/knowledge_retrieval_node.py
@classmethod
def _extract_variable_selector_to_variable_mapping(cls, *, graph_config, node_id, node_data):
typed_node_data = KnowledgeRetrievalNodeData.model_validate(node_data)
variable_mapping = {}
if typed_node_data.query_variable_selector:
variable_mapping[node_id + ".query"] = typed_node_data.query_variable_selector
if typed_node_data.query_attachment_selector:
variable_mapping[node_id + ".queryAttachment"] = typed_node_data.query_attachment_selector
# ❌ This completely fails to handle variable references in metadata_filtering_conditions!
return variable_mapping
This leads to _resolve_metadata_filtering_conditions() failing to find the corresponding variable in the variable_pool when variable_pool.convert_template("{{#node_id.var#}}") is called at runtime, causing the filtering condition to become ineffective.
The reason constants work normally is that constant values (e.g., "abc") do not have {{#...#}} placeholders in the template during convert_template, so they are returned as-is and do not rely on the variable pool at all.
Execution Flow Comparison
| Constant | Variable | |
|---|---|---|
| Storage Format | \"abc\" |
\"{{#start.my_var#}}\" |
| Depends on Variable Pool | No, used directly | Yes, retrieves value from pool at runtime |
| Requires Pre-registration | No | Yes, must be registered in _extract_variable_selector_to_variable_mapping |
| v1.13.0 Result | Normal |
Failed |
Suggested Fix
In the _extract_variable_selector_to_variable_mapping method, add the registration logic for variable references within metadata_filtering_conditions. Parse the {{#...#}} template in each condition.value and add the corresponding variables to variable_mapping.
Environment Information
-
Dify Version: v1.13.0 (Docker self-deployed)
-
Version Comparison: v1.11.4 normal, v1.13.0 abnormal
-
Problem Path:
api/dify_graph/nodes/knowledge_retrieval/knowledge_retrieval_node.py
Hope the official team can fix this soon, thank you!