RabbitMQ 的分片插件（rabbitmq_sharding）允许将消息分布到多个队列中，这在消息量很大或处理速度要求高的情况下非常有用。分片功能通过将消息拆分到多个队列中来平衡负载，从而提升消息处理的吞吐量和可靠性。它能够在多个队列之间分配负载，避免单个队列过载。（注：不能单独消费分片消息。消息分片不利于消息顺序区分）

启用消息分片插件。 

rabbitmq-plugins enable rabbitmq_sharding 

示例

通过rabbitmq management添加策略，用于分片消息匹配转发。

或者通过命令添加策略 

CTL set_policy images-shard "queue10" '{"shards-per-node": 3, "routing-key": "sharding"}'

producer.ts

import RabbitMQ from 'amqplib';


async function start() {
  try {
    const conn = await RabbitMQ.connect("amqp://admin:admin1234@localhost:5672//mirror?heartbeat=60");

    conn.on("error", function (err1) {
      if (err1.message !== "Connection closing") {
        console.error("[AMQP] conn error", err1.message);
      }
    });

    conn.on("close", function () {
      console.error("[AMQP] reconnecting");
      return setTimeout(start, 1000);
    });

    console.log("[AMQP] connected");

    let channel = null;
    try {
      channel = await conn.createChannel();
    } catch (err) {
      console.error("[AMQP]", err);
      return setTimeout(start, 1000);
    }

    const exchangeName = 'exchange_queue10';
    await channel.assertExchange(
      exchangeName,
      'x-modulus-hash',
      {
        durable: true,
        arguments: {
          'x-modulus': 3 // 分片数量（需与队列分片数匹配）
        }
      },
    );

    let routeKey = '';
    for (let i = 0; i < 1000; ++i) {
      // console.log('message send!', channel.sendToQueue(
      //   queueName,
      //   Buffer.from(`发送消息,${i}${Math.ceil(Math.random() * 100000)}`),
      //   { persistent: true, correlationId: 'ooooooooooooooo' },// 消息持久化，重启后存在
      //   // (err: any, ok: Replies.Empty)=>{}
      // ));

      let num = Math.ceil(Math.random() * 100000);
      console.log('消息发送是否成功', num, routeKey, channel.publish(
        exchangeName,
        `${routeKey}${i}`,
        Buffer.from(`"发送消息, index:${i}, number:${num}, routeKey:${JSON.stringify(routeKey)}"`),
        {
          persistent: true,
        },
      ));
    }

    setTimeout(() => {
      conn.close();
      process.exit(0);
    }, 1000);
  } catch (err) {
    console.error("[AMQP]", err);
    return setTimeout(start, 1000);
  }
}

start();

consumer.ts

import RabbitMQ, { type Replies } from 'amqplib/callback_api';


RabbitMQ.connect('amqp://admin:admin1234@localhost:5672//mirror', (err0, conn) => {
  if (err0) {
    console.error(err0);
    return;
  }

  conn.createChannel(function (err1, channel) {
    console.log('[*] waiting...');

    const exchangeName = 'exchange_queue10';

    channel.prefetch(32);

    // for(let i=0;i<3;++i){
    //   channel.assertQueue(queueName, { durable: true }, () => {
    //     channel.bindQueue(queueName, exchangeName, `shard_${shardId}`);
    //   });
    // }

    channel.consume(exchangeName, function (msg) {
      if(msg){
        console.log(`队列'${exchangeName}'接收到的消息`, msg?.content.toString());
        // 第二个参数，false拒绝当前消息
        // 第二个参数，true拒绝小于等于当前消息
        // 第三个参数，3false从队列中清除
        // 第三个参数，4true从新在队列中排队
        channel.nack(msg, false, false);
      }
    }, {
      // noAck: true, // 是否自动确认消息，为true不需要调用channel.ack(msg);
      noAck: false,
      arguments: {}
    }, (err: any, ok: Replies.Empty) => {
      console.log(err, ok);
    });

  });

  conn.on("error", function (err1) {
    if (err1.message !== "Connection closing") {
      console.error("[AMQP] conn error", err1.message);
    }
  });

  conn.on("close", function () {
    console.error("[AMQP] reconnecting");
  });
});