Remove DNS cache from client_routes

- Remove socket import and DNS resolution from resolve_host
- Remove cache_ttl_seconds parameter from ClientRoutesConfig
- Remove dead _dns_cache/_dns_cache_lock type annotations
- Remove cache_ttl_seconds from tests

Author: dkropachev

cassandra/client_routes.py

@@ -24,9 +24,8 @@
 from dataclasses import dataclass
 import enum
 import logging
-import socket
 import threading
-from time import sleep
+import time
 import uuid
 from typing import TYPE_CHECKING, Dict, List, Optional, Sequence, Set, Tuple
 
@@ -75,14 +74,11 @@ class ClientRoutesConfig:
     Configuration for client routes (Private Link support).
 
     :param contact_points: List of ClientRoutesContactPoint objects (REQUIRED, at least one)
-    :param cache_ttl_seconds: How long DNS resolution results are cached (default: 300 seconds = 5 minutes)
     """
 
-    def __init__(self, contact_points: List[ClientRoutesContactPoint],
-                 cache_ttl_seconds: int = 300):
+    def __init__(self, contact_points: List[ClientRoutesContactPoint]):
         """
         :param contact_points: List of ClientRoutesContactPoint objects
-        :param cache_ttl_seconds: DNS cache TTL in seconds (must be >= 0, default: 300 = 5 minutes)
         """
         if not contact_points:
             raise ValueError("At least one contact point must be specified")
@@ -215,8 +211,6 @@ class _ClientRoutesHandler:
     ssl_enabled: bool
     _routes: _RouteStore
     _initial_contact_points: Set[str]
-    _dns_cache: Dict[str, Tuple[str, float]]
-    _dns_cache_lock: threading.Lock
 
     def __init__(self, config: 'ClientRoutesConfig', ssl_enabled: bool = False):
         """
@@ -400,17 +394,4 @@ def resolve_host(self, host_id: uuid.UUID) -> Optional[Tuple[str, int]]:
         if route is None:
             return None
 
-        if not route.port:
-            raise AttributeError("Mapping for host %s has no port" % host_id)
-
-        try:
-            result = socket.getaddrinfo(route.address, route.port,
-                                        socket.AF_UNSPEC, socket.SOCK_STREAM)
-            if not result:
-                raise socket.gaierror("No addresses found for %s" % route.address)
-            resolved_ip = result[0][4][0]
-            return resolved_ip, route.port
-        except socket.gaierror as e:
-            log.warning('[client routes] Could not resolve hostname "%s" (host_id=%s): %s',
-                        route.address, host_id, e)
-            raise
+        return route.address, route.port

tests/integration/standard/test_client_routes.py

@@ -702,7 +702,7 @@ def _make_client_routes_cluster(self, **extra_kwargs):
             port=self.nlb.discovery_port,
             client_routes_config=ClientRoutesConfig(
                 contact_points=[ClientRoutesContactPoint(self.connection_id, NLBEmulator.LISTEN_HOST)],
-                cache_ttl_seconds=0,
+
             ),
             load_balancing_policy=RoundRobinPolicy(),
             **extra_kwargs,
@@ -824,7 +824,7 @@ def test_route_update_causes_reconnect_to_new_port(self):
                 port=nlb_v1.discovery_port,
                 client_routes_config=ClientRoutesConfig(
                     contact_points=[ClientRoutesContactPoint(self.connection_id, NLBEmulator.LISTEN_HOST)],
-                    cache_ttl_seconds=0,
+    
                 ),
                 load_balancing_policy=RoundRobinPolicy(),
             ) as cluster:
@@ -957,7 +957,7 @@ def test_mixed_direct_and_nlb_connections(self):
                 contact_points=["127.0.0.1"],
                 client_routes_config=ClientRoutesConfig(
                     contact_points=[ClientRoutesContactPoint(self.connection_id, NLBEmulator.LISTEN_HOST)],
-                    cache_ttl_seconds=0,
+    
                 ),
                 load_balancing_policy=RoundRobinPolicy(),
             ) as cluster:
@@ -1088,7 +1088,7 @@ def routes_visible():
                 ssl_context=ssl_ctx,
                 client_routes_config=ClientRoutesConfig(
                     contact_points=[ClientRoutesContactPoint(self.connection_id, NLBEmulator.LISTEN_HOST)],
-                    cache_ttl_seconds=0,
+    
                 ),
                 load_balancing_policy=RoundRobinPolicy(),
             ) as cluster:
@@ -1178,7 +1178,7 @@ def test_should_survive_full_node_replacement_through_nlb(self):
                 port=nlb.discovery_port,
                 client_routes_config=ClientRoutesConfig(
                     contact_points=[ClientRoutesContactPoint(self.connection_id, NLBEmulator.LISTEN_HOST)],
-                    cache_ttl_seconds=0,
+    
                 ),
                 load_balancing_policy=RoundRobinPolicy(),
             ) as cluster:

tests/unit/test_client_routes.py

@@ -52,12 +52,7 @@ def test_config_invalid_contact_point_type(self):
         with self.assertRaises(TypeError):
             ClientRoutesConfig(["not-a-contact-point"])
 
-    def test_config_cache_ttl_validation(self):
-        ep = ClientRoutesContactPoint(str(uuid.uuid4()))
-        with self.assertRaises(ValueError):
-            ClientRoutesConfig([ep], cache_ttl_seconds=-1)
-        config = ClientRoutesConfig([ep], cache_ttl_seconds=0)
-        self.assertEqual(config.cache_ttl_seconds, 0)
+
 
 
 class TestRouteStore(unittest.TestCase):