Send ack messages on freeze and unfreeze, add is-frozen to runtime st…

…atistics response

src/handlers/broker_handler.cpp

@@ -510,6 +510,11 @@ void broker_handler::process_client_get_runtime_stats(
 		response.data.push_back(std::to_string(pair.second));
 	}
 
+	// additional statistics
+	response.data.push_back("is-frozen");
+	response.data.push_back(std::to_string(is_frozen_));
+
+	logger_->debug("Client requested runtime statistics");
 	respond(response);
 }
 
@@ -518,11 +523,17 @@ void broker_handler::process_client_freeze(
 {
 	is_frozen_ = true;
 	logger_->info("The broker was frozen and will not accept any requests until it is restarted or unfrozen");
+
+	// let client know that freeze was successful
+	respond(message_container(broker_connect::KEY_CLIENTS, identity, {"ack"}));
 }
 
 void broker_handler::process_client_unfreeze(
 	const std::string &identity, const std::vector<std::string> &message, const handler_interface::response_cb &respond)
 {
 	is_frozen_ = false;
 	logger_->info("The broker was unfrozen and will now accept requests again");
+
+	// let client know that unfreeze was successful
+	respond(message_container(broker_connect::KEY_CLIENTS, identity, {"ack"}));
 }

tests/broker.cpp

@@ -228,7 +228,9 @@ TEST(broker, freeze)
 
 	// The broker is frozen
 	handler.on_request(message_container(broker_connect::KEY_CLIENTS, client_id, {"freeze"}), respond);
-	ASSERT_EQ(0u, messages.size());
+	ASSERT_EQ(1u, messages.size());
+
+	messages.clear();
 
 	// The client requests another evaluation
 	handler.on_request(