Lean Spring Boot Applications for The Cloud by Patrick Baumgartner @ Spring I/O 2024

Summary

This presentation explores optimization strategies for Spring Boot applications, especially when migrating to the cloud. The speaker, Patrick, shares insights on JVM and Spring Boot tuning, application profiling with tools like Spring Boot's startup report, and leveraging build packs for containerization. He benchmarks Java versions, demonstrates the impact of AOT processing, and discusses the benefits of different runtimes like OpenJ9 and GraalVM Native Images. The talk concludes with practical tips for reducing startup time and memory usage, emphasizing the importance of tailored benchmarks for specific applications.

Takeaways

• 🌟 Optimizing Spring Boot applications is crucial for cloud environments where resources and startup times differ significantly from traditional setups.
• 🔧 The presenter, Patrick, emphasizes the importance of benchmarking your own applications to understand their specific needs and the best optimization strategies.
• 🚀 Using build packs can greatly simplify the containerization process and improve security and efficiency, automatically handling many best practices.
• 🛠️ Java and Spring Boot versions matter for performance; newer versions and patch levels can offer better performance, so staying up-to-date is important.
• 🔄 Enabling Ahead-of-Time (AOT) processing can speed up application startup times by eliminating the need for classpath scanning at runtime.
• 📈 The use of Application ClassData Sharing (ACDS) and other runtime optimizations can lead to significant reductions in memory usage and improved throughput.
• 🛑 Disabling Spring Boot Actuators when not needed can reduce the number of Spring beans and improve startup times, although this may not always be advisable.
• 📚 The script suggests using tools like DepClean to analyze and potentially remove unused dependencies, leading to a leaner and faster application.
• 🔧 JVM tuning, including setting parameters like `--noverify` and `--tiered`, can improve startup times, although these may impact runtime performance.
• 🔄 The use of different JVMs, such as OpenJ9 for memory efficiency or GraalVM for JIT optimizations, can be beneficial depending on the application's needs.
• 🔒 Security is highlighted as a concern with technologies like Project Loom and Shenandoah, where secrets may be included in memory dumps, requiring careful handling in production.

Q & A

What is the main topic of the presentation?

The main topic of the presentation is optimizing Spring Boot applications for cloud environments, focusing on startup times, resource usage, and throughput.

Why is it important to optimize applications for the cloud?

Optimizing applications for the cloud is important because cloud resources differ from traditional on-premises servers, and optimizing can lead to better performance, reduced costs, and efficient use of cloud resources.

What is the role of Patrick, the presenter, in the software community?

Patrick is a consultant working with software teams to create real solutions. He is involved in architecture, Spring since 2007, and also teaches at the University of Applied Sciences. He is active in the software development community, including Java user groups.

Why is the Spring PetClinic application used as a baseline for the benchmarks?

The Spring PetClinic application is used as a baseline because it is a well-known, simple application that can be easily understood and used for benchmarking purposes by the audience.

What does the presenter mean by 'the problem with moving to the cloud is that things change slightly'?

The presenter is referring to the changes in resource consumption and availability when moving applications to the cloud, such as the shift from 'beefy machines' to potentially limited virtual CPU resources.

What is the significance of Java version and patch level in application performance?

The Java version and patch level are significant because they can affect the performance of an application. Newer versions and patches often include performance improvements and optimizations.

What is the role of build packs in containerizing applications?

Build packs, implemented with Paketo, help to containerize applications by providing a standardized way to create Docker images. They reduce the cognitive load on developers by handling many aspects of container creation automatically.

What are some JVM optimizations that can be done for faster startup?

Some JVM optimizations for faster startup include using the 'no verify' option to skip class verification, using the 'TieredStopAtLevel1' option to use the C1 compiler, and tweaking memory parameters with the JVM memory calculator.

What is the purpose of Spring Boot Actuators and should they always be used?

Spring Boot Actuators provide production-ready features for applications, such as health checks and metrics. However, they come with an overhead, so the presenter suggests that if they are not needed, they should be disabled to reduce startup time and resource usage.

What is the benefit of using Spring AOT (Ahead Of Time) processing?

Spring AOT processing improves startup time by eliminating the need for classpath scanning at runtime. It pre-generates code that registers Spring beans, which can be faster and more efficient.

How can the presenter's benchmarks help someone optimize their own Spring Boot application?

The benchmarks provide a set of data points and insights into how different configurations and optimizations affect application performance. However, the presenter emphasizes that each application is unique, and developers should perform their own benchmarks to find the best optimizations for their specific use case.