Replace tenacity retries with manual Memgraph transaction retries

- Implement manual retry logic
- Add exponential backoff with jitter
- Improve error handling for transient errors

lightrag/kg/memgraph_impl.py

@@ -1,4 +1,6 @@
 import os
+import asyncio
+import random
 from dataclasses import dataclass
 from typing import final
 import configparser
@@ -11,20 +13,11 @@ import pipmaster as pm
 
 if not pm.is_installed("neo4j"):
     pm.install("neo4j")
-if not pm.is_installed("tenacity"):
-    pm.install("tenacity")
-
 from neo4j import (
     AsyncGraphDatabase,
     AsyncManagedTransaction,
 )
-from neo4j.exceptions import TransientError
-from tenacity import (
-    retry,
-    stop_after_attempt,
-    wait_exponential,
-    retry_if_exception_type,
-)
+from neo4j.exceptions import TransientError, ResultFailedError
 
 from dotenv import load_dotenv
 
@@ -111,25 +104,6 @@ class MemgraphStorage(BaseGraphStorage):
         # Memgraph handles persistence automatically
         pass
 
-    @retry(
-        stop=stop_after_attempt(5),
-        wait=wait_exponential(multiplier=1, min=1, max=10),
-        retry=retry_if_exception_type(TransientError),
-        reraise=True,
-    )
-    async def _execute_write_with_retry(self, session, operation_func):
-        """
-        Execute a write operation with retry logic for Memgraph transient errors.
-
-        Args:
-            session: Neo4j session
-            operation_func: Async function that takes a transaction and executes the operation
-
-        Raises:
-            TransientError: If all retry attempts fail
-        """
-        return await session.execute_write(operation_func)
-
     async def has_node(self, node_id: str) -> bool:
         """
         Check if a node exists in the graph.
@@ -463,7 +437,7 @@ class MemgraphStorage(BaseGraphStorage):
 
     async def upsert_node(self, node_id: str, node_data: dict[str, str]) -> None:
         """
-        Upsert a node in the Memgraph database with retry logic for transient errors.
+        Upsert a node in the Memgraph database with manual transaction-level retry logic for transient errors.
 
         Args:
             node_id: The unique identifier for the node (used as label)
@@ -480,36 +454,77 @@ class MemgraphStorage(BaseGraphStorage):
                 "Memgraph: node properties must contain an 'entity_id' field"
             )
 
-        try:
-            async with self._driver.session(database=self._DATABASE) as session:
-                workspace_label = self._get_workspace_label()
+        # Manual transaction-level retry following official Memgraph documentation
+        max_retries = 100
+        initial_wait_time = 0.2
+        backoff_factor = 1.1
+        jitter_factor = 0.1
 
-                async def execute_upsert(tx: AsyncManagedTransaction):
-                    query = f"""
-                    MERGE (n:`{workspace_label}` {{entity_id: $entity_id}})
-                    SET n += $properties
-                    SET n:`{entity_type}`
-                    """
-                    result = await tx.run(
-                        query, entity_id=node_id, properties=properties
-                    )
-                    await result.consume()  # Ensure result is fully consumed
+        for attempt in range(max_retries):
+            try:
+                logger.debug(
+                    f"Attempting node upsert, attempt {attempt + 1}/{max_retries}"
+                )
+                async with self._driver.session(database=self._DATABASE) as session:
+                    workspace_label = self._get_workspace_label()
 
-                await self._execute_write_with_retry(session, execute_upsert)
-        except TransientError as e:
-            logger.error(
-                f"Memgraph transient error during node upsert after retries: {str(e)}"
-            )
-            raise
-        except Exception as e:
-            logger.error(f"Error during node upsert: {str(e)}")
-            raise
+                    async def execute_upsert(tx: AsyncManagedTransaction):
+                        query = f"""
+                        MERGE (n:`{workspace_label}` {{entity_id: $entity_id}})
+                        SET n += $properties
+                        SET n:`{entity_type}`
+                        """
+                        result = await tx.run(
+                            query, entity_id=node_id, properties=properties
+                        )
+                        await result.consume()  # Ensure result is fully consumed
+
+                    await session.execute_write(execute_upsert)
+                    break  # Success - exit retry loop
+
+            except (TransientError, ResultFailedError) as e:
+                # Check if the root cause is a TransientError
+                root_cause = e
+                while hasattr(root_cause, "__cause__") and root_cause.__cause__:
+                    root_cause = root_cause.__cause__
+
+                # Check if this is a transient error that should be retried
+                is_transient = (
+                    isinstance(root_cause, TransientError)
+                    or isinstance(e, TransientError)
+                    or "TransientError" in str(e)
+                    or "Cannot resolve conflicting transactions" in str(e)
+                )
+
+                if is_transient:
+                    if attempt < max_retries - 1:
+                        # Calculate wait time with exponential backoff and jitter
+                        jitter = random.uniform(0, jitter_factor) * initial_wait_time
+                        wait_time = (
+                            initial_wait_time * (backoff_factor**attempt) + jitter
+                        )
+                        logger.warning(
+                            f"Node upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f} seconds... Error: {str(e)}"
+                        )
+                        await asyncio.sleep(wait_time)
+                    else:
+                        logger.error(
+                            f"Memgraph transient error during node upsert after {max_retries} retries: {str(e)}"
+                        )
+                        raise
+                else:
+                    # Non-transient error, don't retry
+                    logger.error(f"Non-transient error during node upsert: {str(e)}")
+                    raise
+            except Exception as e:
+                logger.error(f"Unexpected error during node upsert: {str(e)}")
+                raise
 
     async def upsert_edge(
         self, source_node_id: str, target_node_id: str, edge_data: dict[str, str]
     ) -> None:
         """
-        Upsert an edge and its properties between two nodes identified by their labels with retry logic for transient errors.
+        Upsert an edge and its properties between two nodes identified by their labels with manual transaction-level retry logic for transient errors.
         Ensures both source and target nodes exist and are unique before creating the edge.
         Uses entity_id property to uniquely identify nodes.
 
@@ -525,40 +540,83 @@ class MemgraphStorage(BaseGraphStorage):
             raise RuntimeError(
                 "Memgraph driver is not initialized. Call 'await initialize()' first."
             )
-        try:
-            edge_properties = edge_data
-            async with self._driver.session(database=self._DATABASE) as session:
 
-                async def execute_upsert(tx: AsyncManagedTransaction):
-                    workspace_label = self._get_workspace_label()
-                    query = f"""
-                    MATCH (source:`{workspace_label}` {{entity_id: $source_entity_id}})
-                    WITH source
-                    MATCH (target:`{workspace_label}` {{entity_id: $target_entity_id}})
-                    MERGE (source)-[r:DIRECTED]-(target)
-                    SET r += $properties
-                    RETURN r, source, target
-                    """
-                    result = await tx.run(
-                        query,
-                        source_entity_id=source_node_id,
-                        target_entity_id=target_node_id,
-                        properties=edge_properties,
-                    )
-                    try:
-                        await result.fetch(2)
-                    finally:
-                        await result.consume()  # Ensure result is consumed
+        edge_properties = edge_data
 
-                await self._execute_write_with_retry(session, execute_upsert)
-        except TransientError as e:
-            logger.error(
-                f"Memgraph transient error during edge upsert after retries: {str(e)}"
-            )
-            raise
-        except Exception as e:
-            logger.error(f"Error during edge upsert: {str(e)}")
-            raise
+        # Manual transaction-level retry following official Memgraph documentation
+        max_retries = 100
+        initial_wait_time = 0.2
+        backoff_factor = 1.1
+        jitter_factor = 0.1
+
+        for attempt in range(max_retries):
+            try:
+                logger.debug(
+                    f"Attempting edge upsert, attempt {attempt + 1}/{max_retries}"
+                )
+                async with self._driver.session(database=self._DATABASE) as session:
+
+                    async def execute_upsert(tx: AsyncManagedTransaction):
+                        workspace_label = self._get_workspace_label()
+                        query = f"""
+                        MATCH (source:`{workspace_label}` {{entity_id: $source_entity_id}})
+                        WITH source
+                        MATCH (target:`{workspace_label}` {{entity_id: $target_entity_id}})
+                        MERGE (source)-[r:DIRECTED]-(target)
+                        SET r += $properties
+                        RETURN r, source, target
+                        """
+                        result = await tx.run(
+                            query,
+                            source_entity_id=source_node_id,
+                            target_entity_id=target_node_id,
+                            properties=edge_properties,
+                        )
+                        try:
+                            await result.fetch(2)
+                        finally:
+                            await result.consume()  # Ensure result is consumed
+
+                    await session.execute_write(execute_upsert)
+                    break  # Success - exit retry loop
+
+            except (TransientError, ResultFailedError) as e:
+                # Check if the root cause is a TransientError
+                root_cause = e
+                while hasattr(root_cause, "__cause__") and root_cause.__cause__:
+                    root_cause = root_cause.__cause__
+
+                # Check if this is a transient error that should be retried
+                is_transient = (
+                    isinstance(root_cause, TransientError)
+                    or isinstance(e, TransientError)
+                    or "TransientError" in str(e)
+                    or "Cannot resolve conflicting transactions" in str(e)
+                )
+
+                if is_transient:
+                    if attempt < max_retries - 1:
+                        # Calculate wait time with exponential backoff and jitter
+                        jitter = random.uniform(0, jitter_factor) * initial_wait_time
+                        wait_time = (
+                            initial_wait_time * (backoff_factor**attempt) + jitter
+                        )
+                        logger.warning(
+                            f"Edge upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f} seconds... Error: {str(e)}"
+                        )
+                        await asyncio.sleep(wait_time)
+                    else:
+                        logger.error(
+                            f"Memgraph transient error during edge upsert after {max_retries} retries: {str(e)}"
+                        )
+                        raise
+                else:
+                    # Non-transient error, don't retry
+                    logger.error(f"Non-transient error during edge upsert: {str(e)}")
+                    raise
+            except Exception as e:
+                logger.error(f"Unexpected error during edge upsert: {str(e)}")
+                raise
 
     async def delete_node(self, node_id: str) -> None:
         """Delete a node with the specified label

lightrag/operate.py

@@ -1285,7 +1285,7 @@ async def merge_nodes_and_edges(
             namespace = f"{workspace}:GraphDB" if workspace else "GraphDB"
             # Sort the edge_key components to ensure consistent lock key generation
             sorted_edge_key = sorted([edge_key[0], edge_key[1]])
-            logger.info(f"Processing edge: {sorted_edge_key[0]} - {sorted_edge_key[1]}")
+            # logger.info(f"Processing edge: {sorted_edge_key[0]} - {sorted_edge_key[1]}")
             async with get_storage_keyed_lock(
                 f"{sorted_edge_key[0]}-{sorted_edge_key[1]}",
                 namespace=namespace,