Apache Camel consuming from multiple queues on one ActiveMQ instance

Question

I have one instance of an ActiveMQ server running with several data sources pushing data into two queues + one DLQ if message consumption fails. I use Apache Camel to consume and process messages from these queues and want to write it to an InfluxDB.

However, up to now I failed to get the stack running such that Apache Camel consumes all queues in parallel. I always ran into errors of that kind:

ERROR 20831 --- [r[ActiveMQ.DLQ]]
c.c.j.DefaultJmsMessageListenerContainer : Could not refresh JMS
Connection for destination 'ActiveMQ.DLQ' - retrying using
FixedBackOff{interval=5000, currentAttempts=270,
maxAttempts=unlimited}. Cause: Broker: localhost - Client: Influx
Message Queue already connected from tcp://ip-of-machine-running-route:port

How can I consume from multiple queues by one Apache Camel instance?

I tried two approaches:

• Each route activeMQ-queue -> InfluxDB is represented by one component
• All routes are running in one Component class / method, inspired by this post: Camel Multiple Consumers Implementation Issue

Currently, my code looks like this:

Camel Config

@Configuration
public class CamelConfig {

    @Bean
    public ShutdownStrategy shutdownStrategy() {
        MessageLogger.logInfo(getClass(), "Camel Route: STARTING...",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        DefaultShutdownStrategy strategy = new DefaultShutdownStrategy();
        int                     timeout  = 1200;
        MessageLogger.logInfo(getClass(), "Camel Route: Timeout for shutdown: " + timeout + " seconds.",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        strategy.setTimeout(timeout); // TODO make it configurable
        return strategy;
    }
}

ActiveMQ client config

@Configuration
public class ActiveMqClientConfig {

    @Bean
    public ActiveMQConnectionFactory registerActiveMQConnectionFactory() {
        MessageLogger.logInfo(getClass(), "ActiveMQ Listener: STARTING...",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
        connectionFactory.setBrokerURL("tcp://servername:61616");
        connectionFactory.setUserName(username);
        connectionFactory.setPassword(passwd);
        connectionFactory.setUseAsyncSend(false);
        connectionFactory.setClientID("Influx Message Queue");
        connectionFactory.setConnectResponseTimeout(300);
        MessageLogger.logInfo(getClass(), "ActiveMQ Listener: STARTED",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        return connectionFactory;
    }
}

Influx Config

@Configuration
public class InfluxDBClientConfig {

    @Bean
    public InfluxDbOkHttpClientBuilderProvider registerInfluxDbOkHttpClientBuilderProvider() {
        return () -> {
            MessageLogger.logInfo(getClass(), "InfluxDB Client: STARTING...",
                    Thread.currentThread().getStackTrace()[0].getMethodName());
            Builder builder = new OkHttpClient.Builder() //
                    .readTimeout(1200, TimeUnit.SECONDS) //
                    .writeTimeout(1200, TimeUnit.SECONDS) //
                    .connectTimeout(1200, TimeUnit.SECONDS) //
                    .retryOnConnectionFailure(true);
            MessageLogger.logInfo(getClass(), "InfluxDB Client: STARTED - " + builder.toString(),
                    Thread.currentThread().getStackTrace()[0].getMethodName());
            return builder;
        };
    }
}

Component with multiple routes:

@Component
public class ActiveMqToInfluxRoute extends RouteBuilder {
    @Autowired
    private FrameworkConfig frameworkConfig;

    @Override
    public void configure() throws Exception {
        String consumerQueueq = "activemq:queue:queue1?"               //
                + "brokerURL=tcp://ip:port";
        String consumerActiveMqDLQ    = "activemq:queue:ActiveMQ.DLQ?"                     //
                + "brokerURL=tcp://ip:port";
        String consumerQueue2           = "activemq:queue:queue2?"                     //
                + "brokerURL=tcp://ip:port";
        String emitterInfluxDB        = "influxdb://influxDb?databaseName=databaseName"          
                + "&batch=true"                                                            //
                + "&retentionPolicy=retentionPolicy"
        String emitterStreamOut       = "stream:out";

        //************************************************************************
        // Data from cryring_db_inbound to InfluxDB
        //************************************************************************
        from(consumerCryringInbound) //   
                .process(messagePayload -> {
                    Message message = messagePayload.getIn();
                    if (message.getBody(String.class).toString().startsWith("@MultiRecords")) {
                        Processor.processMessage(message.getBody(String.class), message);
                    } else {
                        Processor.processMessage(message);
                    }
                })//
                .to(emitterInfluxDB) //
                .onException(Exception.class) //
                .useOriginalMessage() //
                .handled(true) //
                .log("error") //
                .to(emitterStreamOut);

        //************************************************************************
        // Data from cryring_db_inbound to InfluxDB
        //************************************************************************
        from(consumerActiveMqDLQ) //
                .process(messagePayload -> {
                    Message message = messagePayload.getIn();
                    if (message.getBody(String.class).toString().startsWith("@MultiRecords")) {
                        Processor.processMessage(message.getBody(String.class), message);
                    } else {
                        Processor.processMessage(message);
                    }
                })//
                .to(emitterInfluxDB) //
                .onException(Exception.class) //
                .useOriginalMessage() //
                .handled(true) //
                .log("error") //
                .to(emitterStreamOut);

        //************************************************************************
        // Data from olog_inbound to olog
        //************************************************************************
        from(consumerOlog) //
                .process(messagePayload -> {
                    System.out.println(messagePayload.getIn());
                }) //
                .to(emitterStreamOut);
    }
}

Answer 1

In contrast to what Camel Multiple Consumers Implementation Issue suggests (multiple from().to() routes in one @Component) I managed to make this work by splitting up the routes into individual components each, each having an individual clientId. Furthermore I replaced the static client-ID in the ActiveMQ-configuration by a UUID. Code:

ActiveMQ-Config:

@Configuration
public class ActiveMqClientConfig {

    @Bean
    public ActiveMQConnectionFactory registerActiveMQConnectionFactory() {
        MessageLogger.logInfo(getClass(), "ActiveMQ Listener: STARTING...",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
        connectionFactory.setBrokerURL("tcp://servername:port");
        connectionFactory.setUserName(username);
        connectionFactory.setPassword(password);
        connectionFactory.setUseAsyncSend(false);
        connectionFactory.setClientID(UUID.randomUUID().toString());
        connectionFactory.setConnectResponseTimeout(300);
        MessageLogger.logInfo(getClass(), "ActiveMQ Listener: STARTED",
                Thread.currentThread().getStackTrace()[0].getMethodName());
        return connectionFactory;
    }
}

Route-Components:

@Component
public class ActiveMqToInfluxRoute extends RouteBuilder {
    @Autowired
    private FrameworkConfig frameworkConfig;

    @Override
    public void configure() throws Exception {
        String consumerCryringInbound = "activemq:queue:queue1?"
                + "brokerURL=tcp://activemq-server-ip:port" 
                + "clientId=clientid1";

        String emitterInfluxDB = "influxdb://influxDb?databaseName=influx_db_name"
                + "&batch=true"                                                           
                + "&retentionPolicy=retentionPolicy";

        String emitterStreamOut       = "stream:out";

        //************************************************************************
        // Data from cryring_db_inbound to InfluxDB
        //************************************************************************
        from(consumerCryringInbound)    
                .process(processor code)
                .to(emitterInfluxDB)
                .onException(Exception.class) 
                .useOriginalMessage()
                .handled(true) 
                .log("error") 
                .to(emitterStreamOut);
    }
}

... similar for other routes, each with individual clientId.

Answer 2

Only one client can use a ClientID. They must be unique, and not something you probably want to set manually. Another option might be to set the ClientIDPrefix in order to get a better way to identify which app is consuming.