RocketMQ（三）——————javaAPI (8.重试机制)

 

producer：

**默认超时时间**

/**
* Timeout for sending messages.
*/
private int sendMsgTimeout = 3000;

// 异步发送时 重试次数，默认 2
producer.setRetryTimesWhenSendAsyncFailed(1);
// 同步发送时 重试次数，默认 2
producer.setRetryTimesWhenSendFailed(1);

// 是否向其他broker发送请求 默认false
producer.setRetryAnotherBrokerWhenNotStoreOK(true);

Consumer：

消费超时，单位分钟

`consumer.setConsumeTimeout()`

发送ack，消费失败

`RECONSUME_LATER`

broker投递：

只有在消息模式为MessageModel.CLUSTERING集群模式时，Broker才会自动进行重试，广播消息不重试

重投使用`messageDelayLevel`

默认值：

messageDelayLevel 1s 5s 10s 30s 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 20m 30m 1h 2h

1、生产者样例

//添加重试机制
    public static void main(String[] args) throws Exception {

        DefaultMQProducer producer = new DefaultMQProducer("MQ2Group");

        producer.setNamesrvAddr("127.0.0.1:9876");

        producer.start();

        //异步发送 重试次数 系统默认是2
        producer.setRetryTimesWhenSendAsyncFailed(1);
        //同步发送 重试次数 系统默认是2
//        producer.setRetryTimesWhenSendFailed(1);
        producer.send(new Message("MQ2Topic","回调消息!".getBytes()));
        producer.setRetryAnotherBrokerWhenNotStoreOK(true);
//        producer.shutdown();
        System.out.println("生产者下线！");

    }

2、消费者样例

    //接收消息
    public static void main(String[] args) throws Exception {

        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("MQ2Group");

        consumer.setNamesrvAddr("127.0.0.1:9876");

        consumer.subscribe("MQ2Topic","*");
        consumer.registerMessageListener(new MessageListenerConcurrently() {

            public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> list, ConsumeConcurrentlyContext consumeConcurrentlyContext) {

                for (MessageExt mes: list) {

                    System.out.println("mes : "+new String(mes.getBody()));
                }

                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });



        consumer.start();
        System.out.println("Consumer  start...");
    }