Apache Hudi: The Definitive Guide

Chapter 7. Concurrency Control in Hudi

In the world of databases and data lakehouses, concurrency control is a critical concept that ensures data integrity and consistency in the face of multiple concurrent operations. It defines how different processes, whether they are reading or writing data, coordinate access to the shared data to prevent conflicts and maintain data integrity. Concurrency control is crucial because, without it, uncoordinated access to data can lead to various anomalies such as lost updates, dirty reads, and inconsistent data.

Imagine an ecommerce platform where two customers simultaneously attempt to purchase the last available unit of a high-demand product. If the system lacks proper concurrency control, both transactions might proceed as if the item is available, leading to one customer being charged for a product that is out of stock. This scenario can result in customer complaints, refund processing costs, and damage to brand reputation. By implementing concurrency control mechanisms, the system ensures that only one transaction succeeds, preventing overselling and maintaining accurate inventory records.

In Chapter 3, we provided an overview of Apache Hudi’s write process; in this chapter, we’ll dig deeper into how Hudi handles concurrent operations to protect against these kinds of problems.

Why Concurrency Control Is Harder in Data Lakehouses

Many database systems implement concurrency control mechanisms to handle multiple writers and readers. For instance, ...