Mirrored queues have been a feature in RabbitMQ for quite some time. When using mirrored queues messages are replicated across multiple nodes providing high availability in a RabbitMQ cluster. Each mirrored queue has a master and one or more mirrors, and messages are replicated from the master to its mirrors.
Mirrored Queues operate on synchronous replication, meaning that the master node waits for at least one mirror to acknowledge the receipt of a message before considering it successfully delivered. This impacts performance and can result in throughput issues due to the synchronous nature of replication.
Certain failure scenarios can result in mirrored queues confirming messages too early, potentially resulting in a data loss.
Quorum queues
Quorum Queues are a more recent addition to RabbitMQ, introduced to address some of the limitations posed by Mirrored Queues. They use a different replication model based on the Raft consensus algorithm. In this model, each queue is replicated across multiple nodes, and the consensus algorithm ensures that the data is consistent and available even if some nodes fail.
By default MassTransit automatically creates a queue for you. If you want to use a quorum queue you can use the following code to do this for a specific queue:
| busRegistrationConfigurator.UsingRabbitMq((context, cfg) => | |
| { | |
| // host setup etc. | |
| cfg.ReceiveEndpoint('examplequeue', configurator => | |
| { | |
| configurator.SetQuorumQueue(); | |
| }); | |
| }); |
Or use the configuration callback if you want to apply this for all queues:
| x.AddConfigureEndpointsCallback((name, cfg) => | |
| { | |
| if (cfg is IRabbitMqReceiveEndpointConfigurator rmq) | |
| rmq.SetQuorumQueue(3); | |
| cfg.UseMessageRetry(r => r.Immediate(2)); | |
| }); |