Fix: Add Comprehensive Retry Mechanism for Neo4j Storage Operations

lightrag/kg/neo4j_impl.py

@@ -44,6 +44,23 @@
 logging.getLogger("neo4j").setLevel(logging.ERROR)
 
 
+READ_RETRY_EXCEPTIONS = (
+    neo4jExceptions.ServiceUnavailable,
+    neo4jExceptions.TransientError,
+    neo4jExceptions.SessionExpired,
+    ConnectionResetError,
+    OSError,
+    AttributeError,
+)
+
+READ_RETRY = retry(
+    stop=stop_after_attempt(3),
+    wait=wait_exponential(multiplier=1, min=4, max=10),
+    retry=retry_if_exception_type(READ_RETRY_EXCEPTIONS),
+    reraise=True,
+)
+
+
 @final
 @dataclass
 class Neo4JStorage(BaseGraphStorage):
@@ -352,6 +369,7 @@ async def index_done_callback(self) -> None:
         # Neo4J handles persistence automatically
         pass
 
+    @READ_RETRY
     async def has_node(self, node_id: str) -> bool:
         """
         Check if a node with the given label exists in the database
@@ -385,6 +403,7 @@ async def has_node(self, node_id: str) -> bool:
                     await result.consume()  # Ensure results are consumed even on error
                 raise
 
+    @READ_RETRY
     async def has_edge(self, source_node_id: str, target_node_id: str) -> bool:
         """
         Check if an edge exists between two nodes
@@ -426,6 +445,7 @@ async def has_edge(self, source_node_id: str, target_node_id: str) -> bool:
                     await result.consume()  # Ensure results are consumed even on error
                 raise
 
+    @READ_RETRY
     async def get_node(self, node_id: str) -> dict[str, str] | None:
         """Get node by its label identifier, return only node properties
 
@@ -479,6 +499,7 @@ async def get_node(self, node_id: str) -> dict[str, str] | None:
                 )
                 raise
 
+    @READ_RETRY
     async def get_nodes_batch(self, node_ids: list[str]) -> dict[str, dict]:
         """
         Retrieve multiple nodes in one query using UNWIND.
@@ -515,6 +536,7 @@ async def get_nodes_batch(self, node_ids: list[str]) -> dict[str, dict]:
             await result.consume()  # Make sure to consume the result fully
             return nodes
 
+    @READ_RETRY
     async def node_degree(self, node_id: str) -> int:
         """Get the degree (number of relationships) of a node with the given label.
         If multiple nodes have the same label, returns the degree of the first node.
@@ -563,6 +585,7 @@ async def node_degree(self, node_id: str) -> int:
                 )
                 raise
 
+    @READ_RETRY
     async def node_degrees_batch(self, node_ids: list[str]) -> dict[str, int]:
         """
         Retrieve the degree for multiple nodes in a single query using UNWIND.
@@ -621,6 +644,7 @@ async def edge_degree(self, src_id: str, tgt_id: str) -> int:
         degrees = int(src_degree) + int(trg_degree)
         return degrees
 
+    @READ_RETRY
     async def edge_degrees_batch(
         self, edge_pairs: list[tuple[str, str]]
     ) -> dict[tuple[str, str], int]:
@@ -647,6 +671,7 @@ async def edge_degrees_batch(
             edge_degrees[(src, tgt)] = degrees.get(src, 0) + degrees.get(tgt, 0)
         return edge_degrees
 
+    @READ_RETRY
     async def get_edge(
         self, source_node_id: str, target_node_id: str
     ) -> dict[str, str] | None:
@@ -734,6 +759,7 @@ async def get_edge(
             )
             raise
 
+    @READ_RETRY
     async def get_edges_batch(
         self, pairs: list[dict[str, str]]
     ) -> dict[tuple[str, str], dict]:
@@ -784,6 +810,7 @@ async def get_edges_batch(
             await result.consume()
             return edges_dict
 
+    @READ_RETRY
     async def get_node_edges(self, source_node_id: str) -> list[tuple[str, str]] | None:
         """Retrieves all edges (relationships) for a particular node identified by its label.
 
@@ -851,6 +878,7 @@ async def get_node_edges(self, source_node_id: str) -> list[tuple[str, str]] | N
             )
             raise
 
+    @READ_RETRY
     async def get_nodes_edges_batch(
         self, node_ids: list[str]
     ) -> dict[str, list[tuple[str, str]]]:

pyproject.toml

@@ -47,6 +47,7 @@ pytest = [
     "pytest>=8.4.2",
     "pytest-asyncio>=1.2.0",
     "pre-commit",
+    "ruff",
 ]
 
 api = [
@@ -132,10 +133,11 @@ offline = [
 ]
 
 evaluation = [
-    # Test framework dependencies (for evaluation)
+    # Test framework dependencies
     "pytest>=8.4.2",
     "pytest-asyncio>=1.2.0",
     "pre-commit",
+    "ruff",
     # RAG evaluation dependencies (RAGAS framework)
     "ragas>=0.3.7",
     "datasets>=4.3.0",