CQRS stands for Command and Query Responsibility Segregation, a pattern that separates read and update operations for a data store.
We'll create a fictional scenario where a few services communicate in order to fetch some big chunk of data, asynchronous and incrementally insert it into a relational database, wait until it's ready to process and map it to a non-relational database, then asynchronous analyze each mapped document, while providing an endpoint to fetch it.
We're using docker-compose to manage our infrastructure (as database and other services). After installing docker-compose in your machine, just run docker-compose up -d to set up everything.
The next step is set the relational database. To do so, access the /sql-database directory and read its README file.
After setting up the database, you can start the /fetcher, /mirror and /analyzer services. Go to their directories and read their README files to do that.