feat: make remote evaluation connection pool size configurable

src/amplitude_experiment/remote/client.py

@@ -172,8 +172,8 @@ def __do_fetch(self, user, fetch_options: FetchOptions = None):
     def __setup_connection_pool(self):
         scheme, _, host = self.config.server_url.split('/', 3)
         timeout = self.config.fetch_timeout_millis / 1000
-        self._connection_pool = HTTPConnectionPool(host, max_size=1, idle_timeout=30,
-                                                   read_timeout=timeout, scheme=scheme)
+        self._connection_pool = HTTPConnectionPool(host, max_size=self.config.connection_pool_max_size,
+                                                   idle_timeout=30, read_timeout=timeout, scheme=scheme)
 
     def close(self) -> None:
         """

src/amplitude_experiment/remote/config.py

@@ -18,6 +18,7 @@ def __init__(self, debug=False,
                  fetch_retry_backoff_scalar=1.5,
                  fetch_retry_timeout_millis=10000,
                  server_zone: ServerZone = ServerZone.US,
+                 connection_pool_max_size=1,
                  logger=None):
         """
         Initialize a config
@@ -34,6 +35,10 @@ def __init__(self, debug=False,
                 fetch_retry_backoff_scalar (float): Scales the minimum backoff exponentially.
                 fetch_retry_timeout_millis (int): The request timeout for retrying fetch requests.
                 server_zone (str): Select the Amplitude data center to get flags and variants from, US or EU.
+                connection_pool_max_size (int): The maximum number of HTTP connections kept in the fetch connection
+                  pool, and therefore the maximum number of concurrent fetch requests. Additional concurrent fetches
+                  beyond this limit block waiting for a connection to be released. Defaults to 1 (all fetches in the
+                  process share a single keep-alive connection).
                 logger (logging.Logger): Optional logger instance. If provided, this logger will be used instead of
                   creating a new one. The debug flag only applies when no logger is provided.
 
@@ -49,6 +54,7 @@ def __init__(self, debug=False,
         self.fetch_retry_backoff_scalar = fetch_retry_backoff_scalar
         self.fetch_retry_timeout_millis = fetch_retry_timeout_millis
         self.server_zone = server_zone
+        self.connection_pool_max_size = connection_pool_max_size
         if server_url == DEFAULT_SERVER_URL and server_zone == ServerZone.EU:
             self.server_url = EU_SERVER_URL
 

tests/remote/client_test.py

@@ -124,3 +124,15 @@ def test_fetch_retry_with_response(self, response_code, error_message, should_ca
 
 if __name__ == '__main__':
     unittest.main()
+
+
+class RemoteEvaluationClientConnectionPoolTestCase(unittest.TestCase):
+
+    def test_connection_pool_defaults_to_single_connection(self):
+        with RemoteEvaluationClient(API_KEY) as client:
+            self.assertEqual(client._connection_pool.max_size, 1)
+
+    def test_connection_pool_size_is_configurable(self):
+        config = RemoteEvaluationConfig(connection_pool_max_size=8)
+        with RemoteEvaluationClient(API_KEY, config) as client:
+            self.assertEqual(client._connection_pool.max_size, 8)

tests/remote/config_test.py

@@ -68,3 +68,15 @@ def test_default_logger_only_one_handler_added(self):
 
 if __name__ == '__main__':
     unittest.main()
+
+
+class RemoteEvaluationConfigConnectionPoolTestCase(unittest.TestCase):
+    """Tests for RemoteEvaluationConfig connection pool configuration"""
+
+    def test_connection_pool_max_size_defaults_to_one(self):
+        config = RemoteEvaluationConfig()
+        self.assertEqual(config.connection_pool_max_size, 1)
+
+    def test_connection_pool_max_size_is_stored(self):
+        config = RemoteEvaluationConfig(connection_pool_max_size=8)
+        self.assertEqual(config.connection_pool_max_size, 8)