Rabbitmq nodejs close connection

Question

I have doubts about rabbitmq.

I would like to know if when sending a "pub" message, I need to close the connection to the channel and the amqpblib connection, the same with the consumer? Or the correct thing is to leave the connection opened?

I have this to pub and sub:

public produce = async <T>(queue: string, message: T): Promise<boolean> => {
    try {
      if (!this.connection) await this.start();
      await this.initChannel(queue);
      const sendResult = this.channel.sendToQueue(queue, Buffer.from(message), {
        persistent: true,
      });
      if (!sendResult) {
        await new Promise(resolve => this.channel.once('drain', () => resolve));
      }
      return sendResult;
    } catch (error) {
      Logger.info(error.message);
      return false;
    } finally {
      this.close();
    }
  };

Subscribe

public subscribe = async (
    queue: string,
    onMessage: (msg: IMessage) => boolean,
  ): Promise<void> => {
    if (!this.connection) await this.start();
    const channel = await this.initChannel(queue);
    channel.consume(queue, message => {
      if (!message) return false;
      const body = <IMessage>JSON.parse(message.content.toString());
      if (body && onMessage(body)) onMessage(body);
      channel.ack(message);
    });
  };

And this to init connection and listenner events:

private start = async () => {
    try {
      this.connection = await connect(this.rabbitUrl);
      Logger.info('connect to RabbitMQ success');
      await this.listeners();
    } catch (err) {
      Logger.info(err.message);
      sleep(this.start, 10000);
    }
  };

private listeners = async (): Promise<Connection> => {
    return (
      this.connection.on('error', (err: Error) => {
        Logger.info(err.message);
        sleep(this.start, 10000);
      }) &&
      this.connection.on('close', () => {
        Logger.info('connection to RabbitQM closed!');
        sleep(this.start, 10000);
      })
    );
  };

Answer 1

Creating connection is expensive, channel is lightweight but thread-unsafe in most client.

For Node.js application(single-thread model), it is ideally only have two connections for publish and subscribe, one channel per connection.

So please keep the connection and channel open.