Hermod: Mythic, Mighty, Simple Message Broker

Hermod is a fast and simple gRPC based broker. It's a mini practical project to sail through the Golang and most common used tools and frameworks including:

gRPC/Protobuf
Concurrent programming
Storing data using Cassandra/Postrgres/Redis
Load Testing using K6 and simple golang client
Unit Testing
Monitoring using Prometheus and Grafana
Tracing using Jaeger
Rate Limiting using envoy
Caching and batching for highly better performance
Deploying using docker and kubernetes
Creating helm chart for easy deployment

Structure

For better understanding the core and logical concept of Hermod, i've created a simple prezi presentation. You can find it here. Make sure to check it out!

RPCs Description

Publish Requst

message PublishRequest {
  string subject = 1;
  bytes body = 2;
  int32 expirationSeconds = 3;
}

Fetch Request

message FetchRequest {
  string subject = 1;
  int32 id = 2;
}

Subscribe Request

message SubscribeRequest {
  string subject = 1;
}

RPC Service

service Broker {
  rpc Publish (PublishRequest) returns (PublishResponse);
  rpc Subscribe(SubscribeRequest) returns (stream MessageResponse);
  rpc Fetch(FetchRequest) returns (MessageResponse);
}

Up and Running

Docker

docker-compose -f deployments/docker-compose.yml up

Kubernetes