Docker Compose lets you scale services up and down easily, adding or removing containers to a running service. When a service is running with multiple containers, it's still accessible to other services in the network. Consumers use the service name for discovery, and the DNS server in Docker load-balances requests across all the containers in the service.
Adding more containers doesn't automatically give scale and resilience to your service, though; that depends on the application running the service. You won't get a SQL Server failover cluster just by adding another container to a SQL database service, because SQL Server needs to be explicitly configured for failover. If you add another container, you'll have ...
