Designing for eventual consistency

Depending on the type of applications you have designed in the past, you may or may not have come across the concept of eventual consistency (unless you have worked extensively on distributed transactions-oriented applications). However, it is fairly common in the cloud world. After a data update, if your application can tolerate a few seconds delay before the update is reflected across all replicas of the data, then eventual consistency can lead to better scalability and performance.

Note

Cloud platforms typically store multiple replicas of the data to ensure data durability. For example, the replica of a database table could be stored in several geographically distributed locations.

Normally, eventual consistency is the default behavior in a cloud data service. If the application requires consistent reads at all times, then some cloud data services provide the flexibility to specify strongly consistent reads. However, there are several cloud data services...