diff --git a/api/core/workflow/nodes/knowledge_retrieval/entities.py b/api/core/workflow/nodes/knowledge_retrieval/entities.py
index e9122b1eec..f1767bdf9e 100644
--- a/api/core/workflow/nodes/knowledge_retrieval/entities.py
+++ b/api/core/workflow/nodes/knowledge_retrieval/entities.py
@@ -118,7 +118,7 @@ class KnowledgeRetrievalNodeData(BaseNodeData):
     multiple_retrieval_config: Optional[MultipleRetrievalConfig] = None
     single_retrieval_config: Optional[SingleRetrievalConfig] = None
     metadata_filtering_mode: Optional[Literal["disabled", "automatic", "manual"]] = "disabled"
-    metadata_model_config: ModelConfig
+    metadata_model_config: Optional[ModelConfig] = None
     metadata_filtering_conditions: Optional[MetadataFilteringCondition] = None
     vision: VisionConfig = Field(default_factory=VisionConfig)
 
diff --git a/api/core/workflow/nodes/knowledge_retrieval/knowledge_retrieval_node.py b/api/core/workflow/nodes/knowledge_retrieval/knowledge_retrieval_node.py
index 4e9a38f552..5f092dc2f1 100644
--- a/api/core/workflow/nodes/knowledge_retrieval/knowledge_retrieval_node.py
+++ b/api/core/workflow/nodes/knowledge_retrieval/knowledge_retrieval_node.py
@@ -509,6 +509,8 @@ class KnowledgeRetrievalNode(BaseNode):
         # get all metadata field
         metadata_fields = db.session.query(DatasetMetadata).filter(DatasetMetadata.dataset_id.in_(dataset_ids)).all()
         all_metadata_fields = [metadata_field.name for metadata_field in metadata_fields]
+        if node_data.metadata_model_config is None:
+            raise ValueError("metadata_model_config is required")
         # get metadata model instance and fetch model config
         model_instance, model_config = self.get_model_config(node_data.metadata_model_config)
         # fetch prompt messages
@@ -701,7 +703,7 @@ class KnowledgeRetrievalNode(BaseNode):
         )
 
     def _get_prompt_template(self, node_data: KnowledgeRetrievalNodeData, metadata_fields: list, query: str):
-        model_mode = ModelMode(node_data.metadata_model_config.mode)
+        model_mode = ModelMode(node_data.metadata_model_config.mode)  # type: ignore
         input_text = query
 
         prompt_messages: list[LLMNodeChatModelMessage] = []
diff --git a/api/services/account_service.py b/api/services/account_service.py
index feabd43656..352efb2f0c 100644
--- a/api/services/account_service.py
+++ b/api/services/account_service.py
@@ -1067,15 +1067,6 @@ class TenantService:
         target_member_join.role = new_role
         db.session.commit()
 
-    @staticmethod
-    def dissolve_tenant(tenant: Tenant, operator: Account) -> None:
-        """Dissolve tenant"""
-        if not TenantService.check_member_permission(tenant, operator, operator, "remove"):
-            raise NoPermissionError("No permission to dissolve tenant.")
-        db.session.query(TenantAccountJoin).filter_by(tenant_id=tenant.id).delete()
-        db.session.delete(tenant)
-        db.session.commit()
-
     @staticmethod
     def get_custom_config(tenant_id: str) -> dict:
         tenant = db.get_or_404(Tenant, tenant_id)
diff --git a/docker/.env.example b/docker/.env.example
index ab98a40fef..6149f63165 100644
--- a/docker/.env.example
+++ b/docker/.env.example
@@ -283,11 +283,12 @@ REDIS_CLUSTERS_PASSWORD=
 # Celery Configuration
 # ------------------------------
 
-# Use redis as the broker, and redis db 1 for celery broker.
-# Format as follows: `redis://<redis_username>:<redis_password>@<redis_host>:<redis_port>/<redis_database>`
+# Use standalone redis as the broker, and redis db 1 for celery broker. (redis_username is usually set by defualt as empty)
+# Format as follows: `redis://<redis_username>:<redis_password>@<redis_host>:<redis_port>/<redis_database>`.
 # Example: redis://:difyai123456@redis:6379/1
-# If use Redis Sentinel, format as follows: `sentinel://<sentinel_username>:<sentinel_password>@<sentinel_host>:<sentinel_port>/<redis_database>`
-# Example: sentinel://localhost:26379/1;sentinel://localhost:26380/1;sentinel://localhost:26381/1
+# If use Redis Sentinel, format as follows: `sentinel://<redis_username>:<redis_password>@<sentinel_host1>:<sentinel_port>/<redis_database>`
+# For high availability, you can configure multiple Sentinel nodes (if provided) separated by semicolons like below example:
+# Example: sentinel://:difyai123456@localhost:26379/1;sentinel://:difyai12345@localhost:26379/1;sentinel://:difyai12345@localhost:26379/1
 CELERY_BROKER_URL=redis://:difyai123456@redis:6379/1
 CELERY_BACKEND=redis
 BROKER_USE_SSL=false