Feat #58 - fix backpressure logic and update tests

amqp/service/amq_service.py

@@ -14,8 +14,9 @@ from amqp.adapter.data_message_factory import DataMessageFactory
 from amqp.adapter.logging_utils import logging_info, logging_warning
 from amqp.adapter.service_message_factory import ServiceMessageFactory
 from amqp.config.amq_configuration import AMQConfiguration
-from amqp.model.model import DataMessage
+from amqp.model.model import AMQRoute, DataMessage
 from amqp.rabbitmq.rabbit_mq_client import RabbitMQClient
+from amqp.router.router_consumer import RouterConsumer
 from amqp.service.amq_message_handler import DataMessageHandler
 from amqp.service.tracing import TracingConfig, initialize_telemetry
 
@@ -45,7 +46,8 @@ class AMQService:
         self.data_message_factory = DataMessageFactory.get_instance(
             self.amq_configuration.amq_adapter.generator_id
         )
-        self.rabbit_mq_client = RabbitMQClient(self.amq_configuration)
+        self.router = RouterConsumer(self.amq_configuration)
+        self.rabbit_mq_client = RabbitMQClient(self.amq_configuration, self.router)
         self.tracer = initialize_telemetry(
             tracing_config=TracingConfig(
                 service_name=amq_configuration.amq_adapter.service_name,
@@ -57,8 +59,17 @@ class AMQService:
             self.amq_configuration.amq_adapter.service_name
         )
         self.backpressure_thread: Optional[Thread] = None
+        self.backpressure_handler: Optional[BackpressureHandler] = None
 
+    # =======================================================================
+    # =======================================================================
+    # ====================== A P I   M e t h o d s  =========================
+    # =======================================================================
+    # =======================================================================
     def run(self):
+        """
+        Start the AMQ service, initializing RabbitMQ connection and message handlers.
+        """
         # self.init(loop) will initialize RabbitMQ connection
         asyncio.set_event_loop(self.loop)
         self.loop.run_until_complete(self.init(self.loop, self.service_adapter))
@@ -68,9 +79,57 @@ class AMQService:
         logging.info("***********************************************")
         self.loop.run_forever()
 
+    def backpressure(self, current: int, maximum: int = -1):
+        """
+        Send Backpressure event to the Management Service. The Backpressure logic determines the type of the event
+        based on the current and maximum values.
+        - OVERLOAD event is triggered immediately when the current value exceeds the maximum threshold, which is
+        typically set to 80% of the maximum value.
+        - IDLE event is triggered when the current value drops below 20% of the maximum value and remains there for
+        a IDLE_WINDOW period of time (see BackpressureHandler).
+        - UPDATE event is sent if neither OVERLOAD nor IDLE conditions are met, indicating that the backpressure is
+        within acceptable limits.
+        :param current: Current value of the backpressure metric.
+        :param maximum: Maximum value of the backpressure metric. If undefined or set to lt 0, the maximum is set
+        according to the configuration value 'cm.backpressure.threshold'.
+        """
+        if self.backpressure_handler is not None:
+            if maximum < 0:
+                maximum = self.amq_configuration.backpressure.threshold_threads
+            self.backpressure_handler.update_backpressure_value(current, maximum)
+
+    def rpc(self, service_name: str, fq_method_name: str, **kwargs) -> Future:
+        """
+        Send a Remote Procedure Call (RPC) message to the AMQ service.
+        :param service_name: The service name to receive the RPC message.
+        :param fq_method_name: The fully qualified method name to execute the RPC message.
+        :param kwargs: Additional keyword arguments to be passed to the RPC method.
+        :return: A Future that resolves when the RPC response is received.
+        """
+        route: Optional[AMQRoute] = self.router.find_route_by_service(service_name)
+        if route is not None:
+            message: DataMessage = self.data_message_factory.create_rpc_message(
+                fq_method_name=fq_method_name,
+                swarm_id=self.amq_configuration.amq_adapter.swarm_task_id,
+                **kwargs,
+            )
+            result: Future = self.amq_data_message_handler.send_rpc(route, message)
+            self.set_outstanding_future(message, result)
+            return result
+
+        result = asyncio.Future()
+        result.set_exception(
+            NameError(f"No route exists. Service '{service_name}' not found in routing table.")
+        )
+        return result
+
+    # =======================================================================
+    # ======================  Internal  Methods  ============================
+    # =======================================================================
+
     async def init(self, loop, service_adapter):
         _reply_to_exchange: AbstractRobustExchange = await self.rabbit_mq_client.init(loop)
-        backpressure_handler = BackpressureHandler(
+        self.backpressure_handler = BackpressureHandler(
             channel=self.rabbit_mq_client.channel,
             loop=loop,
             config=self.amq_configuration,
@@ -84,11 +143,12 @@ class AMQService:
             self.rabbit_mq_client,
             self.amq_configuration,
             loop=loop,
-            backpressure_handler=backpressure_handler,
+            backpressure_handler=self.backpressure_handler,
         )
         await self.register_routes()
         await self.rabbit_mq_client.request_routes()
-        self.backpressure_thread = backpressure_handler.start_backpressure_monitor()
+        logging_info("Starting backpressure monitor thread")
+        self.backpressure_thread = self.backpressure_handler.start_backpressure_monitor()
 
     def cleanup(self):
         logging_info("AMQService.cleanup() rmqc=%s", self.rabbit_mq_client)
@@ -122,7 +182,7 @@ class AMQService:
             )
         return None
 
-    def send_message(self, message: DataMessage, future: Future):
+    def set_outstanding_future(self, message: DataMessage, future: Future):
         self.amq_data_message_handler.outstanding[str(message.id())] = future
 
     def remove_outstanding_future(self, message_id: str):