Ensure startup failures clean up server resources

Author: vishal-bala

redisvl/mcp/server.py

@@ -53,23 +53,26 @@ async def startup(self) -> None:
             schema=self.config.to_index_schema(),
             redis_url=self.config.redis_url,
         )
-
-        timeout = self.config.runtime.startup_timeout_seconds
-        index_exists = await asyncio.wait_for(self._index.exists(), timeout=timeout)
-        if not index_exists:
-            if self.config.runtime.index_mode == "validate_only":
-                raise ValueError(
-                    f"Index '{self.config.index.name}' does not exist for validate_only mode"
-                )
-            await asyncio.wait_for(self._index.create(), timeout=timeout)
-
-        # Vectorizer construction may perform provider-specific setup, so keep it
-        # off the event loop and bound it with the same startup timeout.
-        self._vectorizer = await asyncio.wait_for(
-            asyncio.to_thread(self._build_vectorizer),
-            timeout=timeout,
-        )
-        self._validate_vectorizer_dims()
+        try:
+            timeout = self.config.runtime.startup_timeout_seconds
+            index_exists = await asyncio.wait_for(self._index.exists(), timeout=timeout)
+            if not index_exists:
+                if self.config.runtime.index_mode == "validate_only":
+                    raise ValueError(
+                        f"Index '{self.config.index.name}' does not exist for validate_only mode"
+                    )
+                await asyncio.wait_for(self._index.create(), timeout=timeout)
+
+            # Vectorizer construction may perform provider-specific setup, so keep it
+            # off the event loop and bound it with the same startup timeout.
+            self._vectorizer = await asyncio.wait_for(
+                asyncio.to_thread(self._build_vectorizer),
+                timeout=timeout,
+            )
+            self._validate_vectorizer_dims()
+        except Exception:
+            await self.shutdown()
+            raise
 
     async def shutdown(self) -> None:
         """Release owned vectorizer and Redis resources."""

tests/integration/test_mcp/test_server_startup.py

@@ -2,6 +2,7 @@
 
 import pytest
 
+from redisvl.index import AsyncSearchIndex
 from redisvl.mcp.server import RedisVLMCPServer
 from redisvl.mcp.settings import MCPSettings
 
@@ -141,6 +142,40 @@ async def test_server_fails_fast_on_vector_dimension_mismatch(
         await server.startup()
 
 
+@pytest.mark.asyncio
+async def test_server_startup_failure_disconnects_index(
+    monkeypatch, mcp_config_path, worker_id
+):
+    monkeypatch.setattr(
+        "redisvl.mcp.server.resolve_vectorizer_class",
+        lambda class_name: FakeVectorizer,
+    )
+    original_disconnect = AsyncSearchIndex.disconnect
+    disconnect_called = False
+
+    async def tracked_disconnect(self):
+        nonlocal disconnect_called
+        disconnect_called = True
+        await original_disconnect(self)
+
+    monkeypatch.setattr(
+        "redisvl.mcp.server.AsyncSearchIndex.disconnect",
+        tracked_disconnect,
+    )
+    settings = MCPSettings(
+        config=mcp_config_path(
+            index_name=f"mcp-startup-failure-{worker_id}",
+            vector_dims=8,
+        )
+    )
+    server = RedisVLMCPServer(settings)
+
+    with pytest.raises(ValueError, match="Vectorizer dims"):
+        await server.startup()
+
+    assert disconnect_called is True
+
+
 @pytest.mark.asyncio
 async def test_server_shutdown_disconnects_owned_client(
     monkeypatch, mcp_config_path, worker_id