Event sourcing pattern

Event sourcing is an architectural pattern in which the state of an application is determined by a sequence of events. Each event in the sequence is recorded in an append-only event store or stream. Conventionally, most software applications work with data and the application has to maintain the current state of the data by updating it as users work with the data. A typical data process is to read data from the store, make some modifications to it, and update the current state of the data with the new values. The transaction is one that changes the data value. However, this way of data update and keeping up the data consistency has many inherent limitations. It requires a two-phase commit (2PC) when accomplishing distributed transactions. Any 2PC commit reduces the throughput of transactions substantially. When there are many concurrent users, there is a...