This application depends on scala, sbt and docker. It was developed with sbt 1.9.8, scala 3.3.1 and Docker 25.0.3. Other version will likely work for all dependencies.

Below is a diagram of the whole system. The arrows from one service to another represent the direction the data flows.

Built the docker containers by running sbt docker

Run docker compose up -d to start all containers.

After a second or two run the following command in the console.

curl -X POST localhost:8080/api/v1/push_message?message=hello!

you should get a response telling you how long it waited in the gRPC server.

Go to http://localhost:5601/app/dev_tools#/console Run the following query:

GET elastic_messages/_search
{
  "query": {
    "match_all": {}
  }
}

Log into postgres using something like DBeaver. Run the following query:

select * from postgres_messages;

Start a CQL session using docker

docker run --rm -it --network oteldemo-network nuvo/docker-cqlsh cqlsh cassandra 9042 --cqlversion='3.4.6'

then run

select * from store.cassandra_messages;

To see traces for each http request go to http://localhost:16686/search. Individual traces look like what is displayed below.