assens commented on a change in pull request #2837: ARTEMIS-2476: New MQTT subscriptions receive older (not last published) retained message. URL: https://github.com/apache/activemq-artemis/pull/2837#discussion_r324993925
########## File path: artemis-protocols/artemis-mqtt-protocol/src/test/java/org/apache/activemq/artemis/core/protocol/mqtt/MqttClientService.java ########## @@ -0,0 +1,126 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.apache.org/licenses/LICENSE-2.0 + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.activemq.artemis.core.protocol.mqtt; + +import static java.util.Objects.nonNull; +import static org.eclipse.paho.client.mqttv3.MqttConnectOptions.MQTT_VERSION_3_1_1; + +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.ScheduledThreadPoolExecutor; +import java.util.concurrent.ThreadFactory; +import java.util.concurrent.ThreadPoolExecutor; +import java.util.function.Consumer; + +import javax.annotation.PostConstruct; +import javax.annotation.PreDestroy; + +import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken; +import org.eclipse.paho.client.mqttv3.MqttCallback; +import org.eclipse.paho.client.mqttv3.MqttClient; +import org.eclipse.paho.client.mqttv3.MqttConnectOptions; +import org.eclipse.paho.client.mqttv3.MqttException; +import org.eclipse.paho.client.mqttv3.MqttMessage; +import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence; +import org.jboss.logging.Logger; + +import io.netty.util.concurrent.DefaultThreadFactory; + +public class MqttClientService implements MqttCallback { Review comment: Hi. The MQTTRetainMessageManagerTest uses [Eclipse Paho](https://www.eclipse.org/paho/) MQTT client to connect to Artemis. MqttCallback is an interface defined by the Paho client, that provides a call back when a message is received. The MqttClientService used by the MQTTRetainMessageManagerTest uses the Paho MQTT client to publish messages and at the same time implements the MqttCallback to be able to subscribe and receive messages. The MQTTRetainMessageManagerTest uses 4 instances of MqttClientService. - mqttConsumerCount is used only to count the messages received by it as consumer - mqttConsumerBeforePublish is a consumer which subscribes to the fact topic, before any publishing starts. - arrivedCountAferPublish and arrivedCountAferPublish2 are consumers that subscribe after messages are published. See how the actAndAssert method uses the 4 clients. The goal of the test is to assert that retained message received by all client subscriptions (before and after the publish) is equal to the last retained message published. In addition, I've created a [mqtt-test](https://github.com/assens/mqtt-test) project that demonstrates the problem we have with Artemis, and also shows that other brokers such as Ejabberd, Emqx, HiveMQ, Moquette, Mosquitto, RabbitMQ and VerneMQ don't have such problem. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
