As CC's users and customers become more familiar with the system, they begin to ask for more functionality. The CC application is now able to connect to the broker through WebSockets and subscribes to location updates delivered directly from the taxi. Location messages are flowing and CC's app is working great and offering more complex features.
This chapter further demonstrated how to use RPC in RabbitMQ via reply-to queues. The header exchange was introduced to build a system capable of running several versions of the same service in parallel, allowing graceful evolution during updates. Another exciting addition to the CC system took place in this chapter, which was the ability to incorporate data analysis into the system to discover important user patterns and other insights. Header exchanges were thereby explained.
The next chapter covers the all-important production realities that CC must understand going forward. Important topics such as federation features and...
