RabbitMQ

RabbitMQ is one of the most widely deployed open-source message brokers, trusted by tens of thousands of organizations for reliable message delivery. Built on the AMQP 0-9-1 protocol, RabbitMQ provides sophisticated routing capabilities through its exchange-and-queue model, making it particularly well-suited for scenarios where messages need to be routed to different consumers based on content, headers, or routing patterns. When you connect pg_tide to RabbitMQ, your outbox messages are published to exchanges where RabbitMQ's routing rules determine which queues (and ultimately which consumers) receive each message.

When to Use This Sink

Choose RabbitMQ when you need complex message routing patterns (topic exchanges, header-based routing, priority queues), when you are integrating with existing RabbitMQ infrastructure, or when you need per-message acknowledgment with sophisticated dead-letter handling built into the broker itself. RabbitMQ's management UI and mature tooling ecosystem also make it an excellent choice for teams that value operational visibility.

Configuration

Minimal Configuration

SELECT tide.relay_set_outbox(
    'orders-to-rabbit',
    'orders',
    'rabbit-relay',
    '{
        "sink_type": "rabbitmq",
        "url": "amqp://localhost:5672",
        "exchange": "events",
        "routing_key": "orders.created"
    }'::jsonb
);

Production Configuration

SELECT tide.relay_set_outbox(
    'orders-to-rabbit',
    'orders',
    'rabbit-relay',
    '{
        "sink_type": "rabbitmq",
        "url": "amqps://${env:RABBITMQ_USER}:${env:RABBITMQ_PASS}@${env:RABBITMQ_HOST}:5671/%2f",
        "exchange": "events",
        "exchange_type": "topic",
        "routing_key": "{stream_table}.{op}",
        "publisher_confirms": true,
        "mandatory": true,
        "tls_enabled": true,
        "batch_size": 100
    }'::jsonb
);

Configuration Reference

Delivery Guarantees

With publisher_confirms: true (the default), RabbitMQ acknowledges each message after it has been written to disk and (if mirrored) replicated to mirror nodes. This provides at-least-once delivery. Combined with RabbitMQ's built-in deduplication plugin or consumer-side idempotency, you can achieve effectively exactly-once processing.

Routing Patterns

RabbitMQ's routing model is more flexible than simple topic-based systems. The routing_key template combined with exchange types enables powerful patterns:

• Direct exchange: Messages with routing key orders.insert go only to queues bound with that exact key.
• Topic exchange: Messages with routing key orders.insert match queues bound to orders.*, orders.#, or *.insert.
• Fanout exchange: All messages go to all bound queues regardless of routing key (broadcast).
• Headers exchange: Route based on message headers rather than routing key.

Complete Example

-- Publish an order event
SELECT tide.outbox_publish(
    'orders',
    '{"order_id": "ord-99", "status": "paid", "amount": 149.99}'::jsonb,
    'ord-99-paid'
);

Verify with rabbitmqadmin:

rabbitmqadmin get queue=order-processing count=1

Troubleshooting

• "Connection refused" — Check RabbitMQ is running and the port is correct (5672 for AMQP, 5671 for AMQPS)
• "Access refused" — Verify username/password and that the user has publish permission on the exchange
• "Exchange not found" — Create the exchange first or set exchange_declare: true if supported
• Messages not arriving in queue — Check queue bindings match the routing key pattern

Further Reading

• Sources: RabbitMQ — Consuming from RabbitMQ into pg_tide inbox
• Content-Based Routing — Dynamic routing key templates