Description
I have a RabbitMQ cluster with multiple nodes. In order to have redundancy the application needs to be able to connect to all of the nodes. As of now, Symfony Messenger does not allow you to specify more than one node. Right now we "solve" the problem by using HAProxy. It would be better if Symfony allowed you to specify all of the nodes in the DSN.

Proposal
The default AMQP extension of PHP does not allow you to specify multiple nodes (as far as I'm concerned). The library php-amqplib allows you to do this with its AMQPStreamConnection class. Like this:

$connection = AMQPStreamConnection::create_connection([
    ['host' => HOST1, 'port' => PORT, 'user' => USER, 'password' => PASS, 'vhost' => VHOST],
    ['host' => HOST2, 'port' => PORT, 'user' => USER, 'password' => PASS, 'vhost' => VHOST]
],
$options);

I propose something similar as how Symfony uses Redis Sentinel. To use Redis Sentinel you need the Predis library and you can specify your DSN as follows:

redis:?host[redis1:26379]&host[redis2:26379]&host[redis3:26379]&redis_sentinel=mymaster

Then for AMQP you would specify the DSN as follows:

amqp:?host[node1:5672]&host[node2:5672]&host[node3:5672]