Summary
In this chapter, we learned that modern systems need to operate in an eventually consistent world and that eventual consistency is based on transparency, facts, and a well-crafted chain reaction. You learned how to increase team confidence by using an event hub to create an outbound bulkhead between upstream and downstream services and how the event sourcing pattern turns events into facts by saving them in perpetuity in an event lake.
We dug into the details and we learned how to implement fault-tolerant stream processors and how to observe and optimize a subsystem's messaging channel topology. You learned how to optimize throughput with techniques such as multiplexing, pipelining, asynchronous non-blocking I/O, and sharding. And you learned that regional failover is just a case of protracted eventual consistency.
In the next chapter, we will cover the Command Query Responsibility Segregation (CQRS) pattern and see how it helps us fight data gravity by implementing...