Programming

Even in microservices, where each service has its own database and a SAGA or TCC pattern coordinates commits, every service still relies on local transactions internally. Meanwhile, many applications remain monolithic or partially modular, handling multiple DAOs or repositories within a single DB connection. In both worlds, Spring’s @Transactional is the bedrock for ensuring atomic…

In-memory database tests with @Transactional are great for quick feedback, but they don’t fully capture real concurrency or vendor-specific behaviors in MySQL, PostgreSQL, or Oracle. Plus, if your app calls external services—like a payment gateway—you can’t rely on local rollback to undo a “live” network call. That’s where Testcontainers and mocks come in. By spinning…

Have you ever run a test that inserted some data, crashed, and then left your database in a weird state for the next test? Or spent hours resetting your DB every time you ran your suite, just to avoid leftover rows cluttering the tables? These headaches arise when we fail to test our transactional logic…

A Thorough Exploration of the Internal Mechanism Many developers know that in Spring Boot, you can simply place @Transactional on a method and get declarative transactions. But few realize when and how Spring spots that annotation and what it does behind the scenes to transform your class into a transaction-aware proxy. In this article, we’ll…

You’ve configured your @Transactional settings—propagation, isolation, rollback rules—and verified everything in your code. Yet, sometimes you find a transaction isn’t firing, or a rollback isn’t happening. Why? This chapter examines three frequent culprits and some handy troubleshooting approaches. 1) Most Common Causes 1.1) Bean Not in Spring’s Scope → No Proxy Created Example: To fix…

In our previous articles, we saw how to configure transaction boundaries (Propagation), handle concurrency through Isolation, specify rollback exceptions, and fine-tune performance with readOnly or timeout. But after setting all these @Transactional properties, a question remains: How exactly does Spring apply those rules to each method call? The short answer: AOP proxies. Whenever you annotate…

In the previous articles, we explored core transaction concepts like Propagation (when and how transactions start or join), Isolation (how to avoid concurrency anomalies), and rollback rules (deciding which exceptions trigger rollbacks). Now, it’s time to look at other Spring transaction attributes that can dramatically improve performance and stability: Let’s see how to configure these…

In the previous articles, we explored how to start or join transactions (propagation) and how to handle concurrency (isolation). However, even if you have those aspects covered, you still need to decide what happens when exceptions occur: What if you need to roll back on a checked exception like IOException? Or what if you want…

In the previous article, we explored the various propagation modes (REQUIRES_NEW, NOT_SUPPORTED, etc.), showing how different pieces of your application can start new transactions or share existing ones. However, even if you’ve got propagation nailed down, that alone won’t guarantee your data remains consistent when multiple users or services hit the database at the same…

In our previous discussions, we discovered how @Transactional can automatically handle commits and rollbacks in Spring. Yet, real-world scenarios raise questions like: That’s exactly where transaction propagation steps in. This article explores the different propagation modes and how each fits common situations in everyday development. 1) What Is Transaction Propagation? Propagation in Spring determines how…