mimi-messaging

Interservice communication via message bus for microservices.

No. Consider this project a WIP.

mimi-messaging is a Messaging layer -- an interservice communication layer based on message bus, for connecting microservice applications.

• Command, Query, Event communication patterns
• "at-least-once" message delivery guarantees
• Abstract message bus interface, not bound to specific message broker implementation

See also: Overview of Messaging layer properties

When it comes to organizing communications between different microservices of a system, currently there is only two options: to use HTTP or a message bus.

Why HTTP is a bad choice for interservice communication?

TBD: Message bus pro's and con's.

Concepts:

• Command: one-to-one, send and forget
• Query: one-to-one, call and wait for response
• Event: one-to-many, broadcast

gem "mimi-messaging", "~> 1.0"
gem "mimi-messaging-<ADAPTER>"

require "mimi/messaging"
require "mimi/messaging/<ADAPTER>"

Mimi::Messaging.use serializer: Mimi::Messaging::JsonSerializer
Mimi::Messaging.configure mq_adapter: "<ADAPTER>", ... # extra adapter specific options
Mimi::Messaging.start

Producing messages:

# COMMAND
Mimi::Messaging.command("users/lock", id: "b3cc29c8d2ec68e0")

# QUERY
response = Mimi::Messaging.query("orders/show", id: 123)

# EVENT

See (/examples)[/examples] folder for more examples on how to produce and consume messages.

mimi-messaging is not bound to a specific message broker implementation like RabbitMQ or Kafka. It interacts with a message broker using an adapter interface and there are several available adapters:

• Kafka
• RabbitMQ (TBD)
• NATS (TBD)
• Amazon SQS/SNS
• (in-memory (single process))[lib/mimi/messaging/adapters/memory.rb]

There are only two hard problems in distributed systems:

2. Exactly-once delivery
1. Guaranteed order of messages
2. Exactly-once delivery

Messaging API specification format

The gem is available as open source under the terms of the MIT License.