This message broker is a software that enables programs, systems and services to communicate with each other and exchange information over gRPC. Broker can have several topics and each message published to certain topic will be broadcasted to all subscribers to that topic.

Features of this broker:

• The possibility of saving messages using the PostgreSQL
• The possibility of using inMemory mode
• Ability to transmit more than 21 thousand messages per second in persistent mode
• Using Prometheus to measure broker performance metrics

The broker run on port 5100 and prometheus metrics can be accessed from :9000/metrics

• 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);
}

You can directly use Docker to run this broker:

docker build -t my-broker . 
docker run -p 9000:9000 -p 5100:5100 my-broker

Or you can run the broker by running the following command:

chmod +x run.sh
./run.sh