1. Preparation

① A built zookeeper cluster is required

② Pull activemq image

docker pull webcenter/activemq

③ Explain

2.docker starts three activemq containers

docker run -d --name activemq_01 -p 61616:61616 -p 8161:8161 webcenter/activemq
docker run -d --name activemq_02 -p 61617:61616 -p 8162:8161 webcenter/activemq
docker run -d --name activemq_03 -p 61618:61616 -p 8163:8161 webcenter/activemq

3.hostname name mapping (if not, just change the hostname of the mq configuration file to the current host ip)

vim /etc/hosts
#Add the following
192.168.16.106 hostname

4.ActiveMQ cluster configuration

① The BrokerName in the configuration file should be consistent

#Enter container instance
docker exec -it activemq_01 /bin/bash
#Modify profile
cd conf
vim activemq.xml
#Change the brokerName in the three activemq configuration files to the same name to prevent confusion
<broker xmlns="http://activemq.apache.org/schema/core" brokerName="activemq_cluster" dataDirectory="${activemq.data}">

② Persistent configuration

Find the persistenceAdapter node, comment out kahaDB and add the following contents. Among them, only the contents of bind are different, and the rest are the same.

Directory: generated directory

Replicas: number of ActiveMQ clusters

bind: cluster communication port

Zkaddress: the address of zookeeper

hostname: host name

sync: synchronize to local disk

Zkpathh: ActiveMQ registers the node path in zookeeper

#activemq_01
<persistenceAdapter>
    <replicatedLevelDB
      directory="${activemq.data}/leveldb"
      replicas="3"
      bind="tcp://0.0.0.0:63631"
      zkAddress="192.168.16.106:2181,192.168.16.106:2182,192.168.16.106:2183"
      hostname="cyfuse"
      sync="local_disk"
      zkPath="/activemq/leveldb-stores"
      />
 </persistenceAdapter>

#activemq_02
<persistenceAdapter>
    <replicatedLevelDB
      directory="${activemq.data}/leveldb"
      replicas="3"
      bind="tcp://0.0.0.0:63632"
      zkAddress="192.168.16.106:2181,192.168.16.106:2182,192.168.16.106:2183"
      hostname="cyfuse"
      sync="local_disk"
      zkPath="/activemq/leveldb-stores"
      />
 </persistenceAdapter>

#activemq_03
<persistenceAdapter>
    <replicatedLevelDB
      directory="${activemq.data}/leveldb"
      replicas="3"
      bind="tcp://0.0.0.0:63633"
      zkAddress="192.168.16.106:2181,192.168.16.106:2182,192.168.16.106:2183"
      hostname="cyfuse"
      sync="local_disk"
      zkPath="/activemq/leveldb-stores"
      />
 </persistenceAdapter>

③ Modify the message port of each node (the port mapped externally when creating the container)

#activemq_01
<transportConnector name="openwire" uri="tcp://0.0.0.0:61616?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>

#activemq_02
<transportConnector name="openwire" uri="tcp://0.0.0.0:61617?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>

#activemq_03
<transportConnector name="openwire" uri="tcp://0.0.0.0:61618?maximumConnections=1000&amp;wireFormat.maxFrameSize=104857600"/>

5. Restart the activemq cluster

① Start the zookeeper cluster first

docker start zookeeper1 zookeeper2 zookeeper3

② Start activemq cluster

docker restart activemq_01 activemq_02 activemq_03

 6. Viewing the zookeeper node

There are three active MQ nodes under discovery

View the content of the node, in which the Master is s elected and the other two are Slave

{"id":"localhost","container":null,"address":"tcp://cyfuse:63631","position":-1,"weight":1,"elected":"0000000000"}
{"id":"localhost","container":null,"address":null,"position":-1,"weight":1,"elected":null}
{"id":"localhost","container":null,"address":null,"position":-1,"weight":1,"elected":null}

7. Cluster availability test

The ActiveMQ client can only access the Broker of the Master, but other brokers in the Slave cannot. Therefore, the Broker connected by the client should use the failover protocol (fail over)

When an ActiveMQ node hangs or a zookeeper node hangs, the ActiveMQ service still runs normally. If there is only one ActiveMQ node left, ActiveMQ cannot run normally because the Master cannot be elected. Similarly, if zookeeper has only one active node, ActiveMQ cannot provide services normally regardless of the survival of ActiveMQ nodes. (the high availability of ActiveMQ cluster depends on the high availability of zookeeper cluster)

Producer code

public class JmsProduce {
    public static final String ACTIVEMQ_URL = "failover:(tcp://192.168.16.106:61616,tcp://192.168.16.106:61617,tcp://192.168.16.106:61618)";
    public static final String QUEUE_NAME = "queue_cluster";
    public static void main(String[] args) throws JMSException {
        // 1. Create a connection factory and use the default user name and password according to the given url address
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(ACTIVEMQ_URL);
        // 2. Get the connection and start it
        Connection connection = factory.createConnection();
        connection.start();

        //3. Create a session
        //Two parameters: ① transaction ② sign in
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        //4. Create destination (specifically queue or topic)
        Queue queue = session.createQueue(QUEUE_NAME);
        //5. Create the producer of the message
        MessageProducer messageProducer = session.createProducer(queue);
        //Set the Queue message produced by the producer created through the session as persistent
        messageProducer.setDeliveryMode(DeliveryMode.PERSISTENT);
        //6. Generate three queues of messages sent to MQ by using messageProducer
        for(int i=0;i<3;i++){
            //7. Create message
            //text type
            TextMessage textMessage = session.createTextMessage("mag---" + i);
            //8. Send to mq through messageProducer
            messageProducer.send(textMessage);
        }
        //9. Close resources
        messageProducer.close();
        session.close();
        connection.close();
        System.out.println("---Publish message to mq---");
    }
}

Consumer code

 public static final String ACTIVEMQ_URL = "failover:(tcp://192.168.16.106:61616,tcp://192.168.16.106:61617,tcp://192.168.16.106:61618)";
    public static final String QUEUE_NAME = "queue_cluster";
    public static void main(String[] args) throws JMSException, IOException {
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(ACTIVEMQ_URL);
        Connection connection = factory.createConnection();
        connection.start();
        //3. Create a session
        //Two parameters: ① transaction ② sign in
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        //4. Create destination (specifically queue or topic)
        Queue queue = session.createQueue(QUEUE_NAME);
        //5. Create consumers
        MessageConsumer messageConsumer = session.createConsumer(queue);
        messageConsumer.setMessageListener(new MessageListener() {
            @Override
            public void onMessage(Message message) {
                if(null != message && message instanceof TextMessage){
                    TextMessage textMessage = (TextMessage) message;
                    try {
                        System.out.println("Received text Message:"+(textMessage.getText()));
                    } catch (JMSException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        System.in.read();//If the console is not destroyed or added, the message will be processed before the program ends
        messageConsumer.close();
        session.close();
        connection.close();
    }

Start the producer, and the console output is as follows, indicating that the connection is successful

 INFO | Successfully connected to tcp://192.168.16.106:61616
---Publish message to mq---

Stop the master of activemq cluster and check whether a new host can be selected

docker stop activemq_01

Since the official has abandoned this cluster method, although a new master can be selected, the producer and consumer can not be connected. We can only see who is the master in zookeeper