fix: handle missing connection_pool attribute in RedisCluster (#93)

RedisCluster doesn't have the connection_pool attribute that standard Redis
clients have. This causes an AttributeError when using from_conn_string()
context managers with Redis deployments that use proxy layers (like Azure
Cache for Redis or Redis Enterprise).

Changes:
- Add getattr check before accessing connection_pool.disconnect()
- Applied to all checkpointer implementations (sync and async)
- Added comprehensive tests for the fix

Fixes #93

Author: bsbodden

langgraph/checkpoint/redis/__init__.py

@@ -1116,7 +1116,9 @@ def from_conn_string(
         finally:
             if saver and saver._owns_its_client:  # Ensure saver is not None
                 saver._redis.close()
-                saver._redis.connection_pool.disconnect()
+                # RedisCluster doesn't have connection_pool attribute
+                if getattr(saver._redis, "connection_pool", None):
+                    saver._redis.connection_pool.disconnect()
 
     def get_channel_values(
         self,

langgraph/checkpoint/redis/aio.py

@@ -229,9 +229,11 @@ async def __aexit__(
         """Async context manager exit."""
         if self._owns_its_client:
             await self._redis.aclose()
-            coro = self._redis.connection_pool.disconnect()
-            if coro:
-                await coro
+            # RedisCluster doesn't have connection_pool attribute
+            if getattr(self._redis, "connection_pool", None):
+                coro = self._redis.connection_pool.disconnect()
+                if coro:
+                    await coro
 
             # Prevent RedisVL from attempting to close the client
             # on an event loop in a separate thread.

langgraph/checkpoint/redis/ashallow.py

@@ -137,9 +137,11 @@ async def __aexit__(
     ) -> None:
         if self._owns_its_client:
             await self._redis.aclose()
-            coro = self._redis.connection_pool.disconnect()
-            if coro:
-                await coro
+            # RedisCluster doesn't have connection_pool attribute
+            if getattr(self._redis, "connection_pool", None):
+                coro = self._redis.connection_pool.disconnect()
+                if coro:
+                    await coro
 
             # Prevent RedisVL from attempting to close the client
             # on an event loop in a separate thread.

langgraph/checkpoint/redis/shallow.py

@@ -155,7 +155,9 @@ def from_conn_string(
         finally:
             if saver and saver._owns_its_client:
                 saver._redis.close()
-                saver._redis.connection_pool.disconnect()
+                # RedisCluster doesn't have connection_pool attribute
+                if getattr(saver._redis, "connection_pool", None):
+                    saver._redis.connection_pool.disconnect()
 
     def put(
         self,

tests/test_issue_93_cluster_connection_pool.py

@@ -0,0 +1,155 @@
+"""Test for issue #93 - RedisCluster connection_pool attribute error."""
+
+from unittest.mock import MagicMock, Mock
+
+import pytest
+from redis import Redis
+from redis.cluster import RedisCluster
+
+from langgraph.checkpoint.redis import RedisSaver
+from langgraph.checkpoint.redis.shallow import ShallowRedisSaver
+
+
+def test_redis_cluster_connection_pool_attribute_error():
+    """Test that connection cleanup now works with RedisCluster which lacks connection_pool."""
+
+    # Create a mock RedisCluster that mimics the real behavior
+    mock_cluster = Mock(spec=RedisCluster)
+    mock_cluster.close = Mock()
+
+    # RedisCluster doesn't have connection_pool attribute
+    # This should raise AttributeError when accessed
+    del mock_cluster.connection_pool
+
+    # Test that the fix allows graceful handling
+    saver = RedisSaver(redis_client=mock_cluster)
+    saver._owns_its_client = True
+
+    # This should NOT fail anymore with our fix
+    saver._redis.close()
+    # The getattr check should prevent the AttributeError
+    if getattr(saver._redis, "connection_pool", None):
+        saver._redis.connection_pool.disconnect()
+
+    # Verify close was called
+    mock_cluster.close.assert_called_once()
+
+
+def test_redis_standard_has_connection_pool():
+    """Test that standard Redis client has connection_pool."""
+
+    # Create a mock standard Redis client
+    mock_redis = Mock(spec=Redis)
+    mock_redis.close = Mock()
+    mock_redis.connection_pool = Mock()
+    mock_redis.connection_pool.disconnect = Mock()
+
+    # This should work fine with standard Redis
+    saver = RedisSaver(redis_client=mock_redis)
+    saver._owns_its_client = True
+
+    # Simulate the finally block in from_conn_string
+    saver._redis.close()
+    saver._redis.connection_pool.disconnect()
+
+    # Verify methods were called
+    mock_redis.close.assert_called_once()
+    mock_redis.connection_pool.disconnect.assert_called_once()
+
+
+def test_proposed_fix_works_with_both():
+    """Test that the proposed fix works with both Redis and RedisCluster."""
+
+    # Test with RedisCluster (no connection_pool)
+    mock_cluster = Mock(spec=RedisCluster)
+    mock_cluster.close = Mock()
+    del mock_cluster.connection_pool  # Remove connection_pool attribute
+
+    saver_cluster = RedisSaver(redis_client=mock_cluster)
+    saver_cluster._owns_its_client = True
+
+    # Proposed fix - check if connection_pool exists
+    saver_cluster._redis.close()
+    if getattr(saver_cluster._redis, "connection_pool", None):
+        saver_cluster._redis.connection_pool.disconnect()
+
+    mock_cluster.close.assert_called_once()
+
+    # Test with standard Redis (has connection_pool)
+    mock_redis = Mock(spec=Redis)
+    mock_redis.close = Mock()
+    mock_redis.connection_pool = Mock()
+    mock_redis.connection_pool.disconnect = Mock()
+
+    saver_redis = RedisSaver(redis_client=mock_redis)
+    saver_redis._owns_its_client = True
+
+    # Same fix should work with standard Redis
+    saver_redis._redis.close()
+    if getattr(saver_redis._redis, "connection_pool", None):
+        saver_redis._redis.connection_pool.disconnect()
+
+    mock_redis.close.assert_called_once()
+    mock_redis.connection_pool.disconnect.assert_called_once()
+
+
+def test_shallow_saver_has_fix_too():
+    """Test that ShallowRedisSaver also has the fix applied."""
+
+    # Create a mock RedisCluster
+    mock_cluster = Mock(spec=RedisCluster)
+    mock_cluster.close = Mock()
+    del mock_cluster.connection_pool
+
+    # ShallowRedisSaver should also work with the fix
+    saver = ShallowRedisSaver(redis_client=mock_cluster)
+    saver._owns_its_client = True
+
+    # This should NOT fail with our fix
+    saver._redis.close()
+    # The getattr check should prevent the AttributeError
+    if getattr(saver._redis, "connection_pool", None):
+        saver._redis.connection_pool.disconnect()
+
+    # Verify close was called
+    mock_cluster.close.assert_called_once()
+
+
+def test_context_manager_with_redis_cluster():
+    """Test that from_conn_string context manager works with RedisCluster."""
+    from unittest.mock import patch
+
+    # Mock the RedisConnectionFactory to return our mock cluster
+    mock_cluster = Mock(spec=RedisCluster)
+    mock_cluster.close = Mock()
+    del mock_cluster.connection_pool
+
+    with patch(
+        "langgraph.checkpoint.redis.RedisConnectionFactory.get_redis_connection"
+    ) as mock_factory:
+        mock_factory.return_value = mock_cluster
+
+        # Test using the context manager doesn't raise AttributeError
+        with RedisSaver.from_conn_string("redis://localhost:6379") as saver:
+            # Use the saver
+            pass
+
+        # Verify close was called (since it owns the client)
+        mock_cluster.close.assert_called_once()
+
+    # Test with ShallowRedisSaver too
+    mock_cluster2 = Mock(spec=RedisCluster)
+    mock_cluster2.close = Mock()
+    del mock_cluster2.connection_pool
+
+    with patch(
+        "langgraph.checkpoint.redis.shallow.RedisConnectionFactory.get_redis_connection"
+    ) as mock_factory2:
+        mock_factory2.return_value = mock_cluster2
+
+        with ShallowRedisSaver.from_conn_string("redis://localhost:6379") as saver:
+            # Use the saver
+            pass
+
+        # Verify close was called
+        mock_cluster2.close.assert_called_once()