goevents

Go channels for distributed systems

Benefits:

• Use Go channels transparently over a messaging technology of your choice
• Write idiomatic Go code instead of using vendor specific APIs
• Write simple and independent unit test (no need to mock interfaces or running the queue technology)

Usage

The following code receives added-wishlist items from one queue and send recommendations to another queue.

wishlistItems, _ := transport.Receive("added-wishlist-items")
recommendations, _ := transport.Send("recommendations")

for received := range wishlistItems {
        
        // Channel to subscribe to the result of sending event 
        sendResult := make(chan error, 1)

        recommendations <- goevents.EventEnvelop{
            Result: sendResult,
            Event:  goevents.JsonEvent(wishlistItem.Context(), getRecommendation(wishlistItem.Event)),
        }
        
        // Acknowledge the processing of the received event
        received.Result <- <-sendResult
    }
}

Features

• Producers can
  • explicitly receive and handle the message's publishing result, enabling at-least-one delivery guarantee
  • Or fire-and-forget (removing the latency related to message publishing)
• Consumers must acknowledge the processing of message to enable message redelivery (at-least-one processing guarantee).
• Support for graceful shutdown to prevent message loses by ensuring all messages are flushed to the queue
• Middlewares to customize the processing of events .e.g. error handling, logging, retry

Supported queue technologies

• Amazon SQS
• Amazon SNS (only send of events)
• Kafka
• Rabbit MQ
• Redis
• Postgres database queue (support at-least-one delivery guarantee for producers with transaction)