Why Upgrade to Spring Boot 3.4.5: Performance, Security, and Cloud‑Native Benefits

Spring Boot 3.4.5 is the latest release packed with performance optimizations, enhanced security features, and cloud-native improvements that make it a compelling upgrade for modern Java applications.

Spring Boot 3.4.5 (released April 2025) is the newest stable version in the 3.x line, and it offers numerous advantages over earlier Spring Boot releases. Whether you're a seasoned Java developer or part of a DevOps team, this version brings tangible benefits in performance, security, and cloud-native support. In this article, we'll explore the key reasons to use Spring Boot 3.4.5, highlight its notable new features, and compare improvements against previous 3.x versions – all with clear, technically accurate explanations. We’ll also point to official documentation and changelogs for reference.

Key Advantages of Spring Boot 3.4.5

Spring Boot 3.4.5 builds upon the foundation of Spring Boot 3.x (which introduced Java 17+, Jakarta EE 10, and AOT support) and delivers refinements that boost performance, tighten security, and enhance cloud-native capabilities. Here are the primary benefits:

Performance and Efficiency Improvements

Faster Startup & Lower Overhead: Continuous optimizations in the Spring Boot framework have improved startup times and memory usage in 3.4.x. For example, internal changes (like using the new WebJars locator library) result in faster application bootstrapping and classpath scanning. The Spring team notes “performance and memory enhancements to optimize application startup times” in Spring Boot 3.4.0.
Virtual Threads (Project Loom) Support: Spring Boot 3.4.x expands support for Java 21 virtual threads, enabling your application to handle many more concurrent requests with minimal thread overhead. The Undertow web server and other components (e.g. Micrometer’s OTLP meter registry) will utilize virtual threads if you enable them. This means thousands of concurrent tasks can be handled using lightweight threads, a “significant scalability boost” over the traditional OS thread model. In practice, enabling spring.threads.virtual.enabled=true allows I/O-bound workloads (REST APIs, database calls) to scale more efficiently on the same hardware.
Optimized JVM & Native Performance: Spring Boot 3.4.5 inherits improvements from Spring Framework 6.2 and related projects that positively impact performance. It leverages Java 17+ and JDK 21 enhancements (like improved garbage collection and Loom) for better runtime performance. The Spring AOT engine and GraalVM native image support introduced in Spring Boot 3.0 have matured – 3.4.x refines AOT processing, yielding quicker native image builds and reduced native runtime footprint (as reported by community benchmarks). In short, applications on 3.4.5 can start faster and handle more load than the same apps on earlier versions.
Smaller Container Images: If you containerize Spring Boot apps, you'll benefit from the new default Cloud Native Buildpacks builder. Spring Boot 3.4 switched the default builder image from Paketo’s large “jammy-base” to the new “paketobuildpacks/builder-jammy-java-tiny”, which produces leaner images. The tiny builder omits unnecessary OS packages (even excluding a shell) and supports both ARM and x86 out of the box, resulting in significantly smaller Docker image sizes and faster deploys. This is a boon for performance (less network transfer, quicker startup) in cloud environments.

Performance and Efficiency Improvements

Security Enhancements and Dependency Updates

Up-to-Date Security Frameworks: Spring Boot 3.4.5 brings in the latest versions of Spring Security, Spring Authorization Server, and other security-related dependencies. Notably, it manages Spring Security 6.4.x (versus 6.1 or 6.2 in earlier 3.x), which includes the newest security patches and features. By using 3.4.5, you ensure your app is built on frameworks that have addressed known CVEs and follow current best practices in authentication and authorization. The same goes for other libraries: Spring Boot 3.4 aligns with Spring Framework 6.2.5+, Spring Data 2024.0.x, Tomcat 10.1, Hibernate 6.2, etc., all bringing their latest security and stability improvements.
More Granular Actuator Access Control: The Actuator in Spring Boot provides operational endpoints (for health, metrics, config, etc.), and 3.4 introduces a new security mode: read-only access. In older versions, an endpoint was either fully enabled (unrestricted) or disabled; now you can mark endpoints as “read-only”, allowing safe exposure of diagnostics without permitting modifications. Corresponding properties have been updated (e.g. management.endpoint.<id>.access replaces ...enabled) to support this granularity. This enhancement means you can confidently expose monitoring endpoints in production with minimal risk, improving security posture for cloud deployments. (For example, you might allow read-only access to metrics while restricting any mutating operations.)
Automatic SSL Certificate Info and Reload: Spring Boot 3.4.x adds features to simplify certificate management. The Actuator’s /actuator/info endpoint now reports SSL certificate details, including expiration dates for certificates your app is using. This helps DevOps teams proactively identify expiring certs in production. Additionally, Spring Boot 3.4 introduced SSL Bundle support – a way to group and hot-reload keystores/truststores. With the ssl.bundle configuration, your application can automatically pick up certificate changes (if reload-on-update=true) without restart. This was not available in Spring Boot 2.x and represents an important security and reliability improvement for handling TLS in microservices.
Safer Image Building (Supply Chain Security): As mentioned above, the build tool plugins for Spring Boot now support a trustBuilder option when creating OCI images. This allows you to restrict which buildpack builders are trusted to run (by default only trusted sources like Paketo, Heroku, Google are allowed). It adds a security gate to your container build process, mitigating the risk of using unverified buildpacks. While this is a low-level improvement, it reflects Spring Boot 3.4.5's attention to security in the software supply chain.
Dependency Auditing (SBOM): Spring Boot 3.4 continues to support generating Software Bill of Materials (SBOM) for your application, a feature introduced in 3.3, to help track dependencies and known vulnerabilities. Using the Maven or Gradle plugin, you can produce an SBOM that lists all libraries your app includes. This, combined with using the latest Boot version, means easier auditing and compliance for security standards. (The SBOM feature is part of the commitment to make apps more secure and transparent, especially in regulated environments.)

Cloud-Native and Observability Improvements

Structured Logging Out of the Box: A major focus of Spring Boot 3.4 is observability. Spring Boot 3.4.5 supports structured logging – writing logs in a machine-readable JSON format following standard schemas. Specifically, it can emit logs in formats like ECS (Elastic Common Schema), Logstash JSON, or GELF (Graylog Extended Log Format). By simply setting properties (logging.structured.format.console/file), you can switch your log output to one of these structured formats, making it far easier to aggregate and analyze logs in ELK stacks, Splunk, or cloud log services without custom log formatters. Earlier Spring Boot versions did not have built-in support for these log formats – 3.4 closed that gap, greatly simplifying log management in production.
Enhanced Tracing and Metrics (Observability): Spring Boot 3.4.5 comes with improved integration for distributed tracing and metrics. It upgrades to Micrometer 1.11+ and OpenTelemetry support is refined. For example, Boot now correctly sets the service.namespace attribute in OTEL traces (important for grouping services in tracing backends). The OTLP tracing exporter can be configured to use gRPC transport in addition to HTTP, simply by a property (management.otlp.tracing.transport=grpc) – enabling more efficient export of traces. Boot 3.4 also adds new config toggles to enable/disable tracing exporters for OTLP, Wavefront, and Zipkin individually, giving you fine-grained control over which tracing systems are active. All these changes mean better out-of-the-box observability for cloud deployments: your Spring Boot 3.4.5 application can emit metrics and traces with minimal setup, and integrate cleanly with modern observability tools.
Application Grouping Metadata: In a microservice landscape, you often have many services and might want to logically group them (by domain or team). Spring Boot 3.4 introduces a new property spring.application.group to tag your application with a group name. This group name then gets included in your logs and in the OpenTelemetry resource attributes automatically. It’s a small but useful feature for cloud-native apps – for example, all services belonging to “payments” vs “orders” can include that in their telemetry, allowing dashboards to filter or group by this custom dimension.
Kubernetes and Cloud-Friendly Behavior: Spring Boot 3.4.5 is even more Kubernetes-friendly than its predecessors:

Graceful Shutdown by Default: Embedded web servers (Tomcat, Jetty, etc.) now perform graceful shutdown by default on Spring Boot 3.4+. This means when your pod is terminated (SIGTERM), the app will stop accepting new requests and wait for in-flight requests to finish for a polite shutdown. In Spring Boot 3.3 and earlier, immediate shutdown was the default (unless you enabled graceful shutdown manually). By aligning with Kubernetes best practices out of the box, 3.4.5 makes your services more robust during deployments or scale-down events.
Docker Compose & Testcontainers Integration: For cloud-native development, Spring Boot 3.4 deepened support for running dependent services via Docker. It introduced properties like spring.docker.compose.start/stop.arguments to pass custom flags to Docker Compose. It also now automatically handles common Docker Compose environment quirks (for example, supporting the POSTGRES_HOST_AUTH_METHOD=trust env var to easily start a throwaway Postgres for testing). On the testing side, Spring Boot 3.4.5 brings improved Testcontainers support – for instance, it now has out-of-the-box integration for Redis Stack and Kafka Testcontainers modules, so these services can be spun up in tests with zero custom code. This is a big improvement over earlier versions where developers had to manually configure Testcontainers for such services. All of this makes developing and testing cloud-native apps (with ephemeral containers, etc.) much easier.

Improved Image Building & Multi-Arch Support: As mentioned earlier, the Spring Boot Maven/Gradle plugin now easily produces OCI images tailored for cloud deployment. With 3.4+, you can specify an imagePlatform to build images for a different OS/architecture than your build machine (useful for building ARM images on an x86 CI server, for example). Plus, the default images support ARM out-of-the-box, which is great for teams using Apple M1/M2 for development or running services on ARM instances in the cloud (AWS Graviton, etc.). These cloud-friendly tooling enhancements streamline the path from code to container to cloud.

In summary, Spring Boot 3.4.5’s advantages can be felt in day-to-day development (faster starts, less config), in production ops (better logs, metrics, and safer actuators), and in the DevOps pipeline (smaller images, easier testing). Next, let's look specifically at some of the new features and updates introduced in the 3.4.x line that make these advantages possible.

Notable New Features in Spring Boot 3.4.5

Spring Boot 3.4.5 includes all the new features from 3.4.0 (released Nov 2024) plus subsequent refinements up to 3.4.5. According to the official release announcement, 3.4 added a significant number of new features and improvements. Here are the highlights of what’s new:

Structured Logging Support: As discussed, 3.4 introduces first-class support for structured log output. Developers can choose JSON log formats compatible with Elasticsearch or Graylog by simple configuration, eliminating the need for custom log appenders. This makes log aggregation and analysis much easier out-of-the-box.
Expanded Virtual Thread Support: Spring Boot 3.4.5 fully supports Java virtual threads in more places. In addition to web server support (Undertow), internal schedulers and metrics exporters can utilize virtual threads when available. This means Spring components are ready to take advantage of Project Loom for highly concurrent workloads. (Boot 3.2 started Loom support, and 3.4 optimized it.)
Docker Compose and Testcontainers Enhancements: Spring Boot 3.4 brought built-in integration with Docker Compose for dev/test. You can declare services in a docker-compose.yaml and Boot will manage them (via the @DynamicPropertySource mechanism) when running tests or the app. Spring Boot 3.4.5 extends this by supporting additional Docker images (like Bitnami variants) and adding Testcontainers support for Redis Stack, Kafka, etc.. This dramatically reduces the friction to write integration tests or run your app locally with all its dependencies.
Actuator Improvements: Several improvements make the Actuator more powerful:

SSL Certificate Info: The new SSL Info endpoint surfaces certificate expiry and other TLS details in /actuator/info, aiding monitoring.
Scheduled Tasks: The /actuator/scheduledtasks endpoint now shows next execution times and last run status/exceptions for scheduled jobs.
Read-Only Endpoints: As noted, you can mark endpoints read-only to expose info safely.
Operational Overrides: (In a Tanzu environment, operators can even override actuator settings centrally – beyond our scope, but highlights enterprise readiness.)

Ability to Define Additional Beans alongside Auto-Config: A subtle but important feature in 3.4 is that you can define your own bean of a type that Spring Boot auto-configures without having to disable the auto-configuration. Boot will now intelligently register multiple beans of the same type if appropriate. For example, if Spring Boot auto-configures a DataSource but you want a second DataSource bean, you can simply define it – previously, auto-config would often back off or conflict. Spring Boot 3.4 “offers support for defining additional beans of the same type as those that are auto-configured”, which gives developers more flexibility to extend built-in configuration.
RestClient and HTTP Clients Choice: Spring Boot 3.4 adds auto-configuration for the new Spring Framework RestClient (a successor to RestTemplate) and enhances RestTemplate as well to autodetect available HTTP client libraries. Now, by default, Boot 3.4 will choose the best HTTP client on the classpath (e.g. Apache HttpClient, Jetty client, Reactor Netty, JDK HTTP) in a defined order. This means if you include, say, Reactor Netty, your RestTemplate will automatically use its non-blocking HttpClient under the hood. You can also force a particular implementation via the spring.http.client.factory property. This new feature gives you optimized HTTP communications without manual config, and is especially useful in reactive or high-load scenarios (e.g., using Reactor Netty’s HTTP client for better performance).
Embedded ActiveMQ Broker Support: If you use ActiveMQ classic for messaging, Spring Boot 3.4 restores the ability to easily spin up an embedded broker for tests or dev. ActiveMQ 5.x had removed embedded broker support in recent versions but added it back, and Boot 3.4’s auto-config will now detect activemq-broker on the classpath and start an in-memory broker for you. (Remember to include the activemq-broker dependency; the ActiveMQ starter itself remains client-only.) This is convenient for testing messaging flows without a full external MQ server.
Apache Pulsar Improvements: Spring Boot 3.4.5 also adds features for Apache Pulsar messaging. It introduces new configuration properties to fine-tune Pulsar client threads and listener concurrency, and a PulsarContainerFactoryCustomizer interface to customize auto-configured Pulsar listener containers. This level of integration was not present in earlier Boot 3.x, reflecting Spring Boot’s expanding support for cloud messaging platforms.
Auto-configuration for Testing (MockMvc & Testcontainers): Test support got a boost. If you have AssertJ on the classpath, Spring Boot 3.4 auto-configures MockMvcTester, which provides a fluent AssertJ-style API for MVC tests. This makes writing unit tests for controllers more expressive (e.g., mockMvcTester.get("/api/users").andAssertThat()...). Additionally, as noted, Testcontainers support is improved with zero-config integration for common services (Redis, Kafka, etc.), and even automatic detection of containerized databases. For example, if you use @Testcontainers for a PostgreSQL container, Boot 3.4 will recognize it and skip the default embedded database replacement (previously you had to use @AutoConfigureTestDatabase(replace=NONE), which is no longer required in many cases).
Gradle 8 and Kotlin 1.9 Support: On the build tool side, Spring Boot 3.4 raises the minimum supported Gradle version to 8.4 (for compatibility with Gradle’s latest improvements). It also supports Kotlin 1.9.x for those writing Spring Boot applications in Kotlin. Keeping tooling up to date ensures better performance and compatibility with modern Java features.

These are just some of the new and noteworthy features in Spring Boot 3.4.x. The official Spring Boot 3.4 release notes enumerate many more minor changes and deprecation, but the items above are the most relevant for most developers. Overall, Spring Boot 3.4.5 is a feature-packed release that smooths over rough edges from earlier versions and adds capabilities that align with today’s development and operations needs.

Spring Boot 3.4.5 vs. Previous 3.x Releases (Comparison)

To appreciate the progress, let’s compare Spring Boot 3.4.5 with previous 3.x versions (3.0 through 3.3). The following table summarizes some improvements in 3.4.x over its predecessors:

Feature/Area	Spring Boot 3.3 and Earlier	Spring Boot 3.4.5 (Latest 3.x)
Performance Concurrency	No built-in virtual threads support (runs on platform threads). Graceful shutdown off by default.	Virtual threads integration for Tomcat/Undertow, etc., enabling high concurrency with low overhead. Graceful shutdown on by default (better Kubernetes support).
Logging & Observability	Plain text logging; no native support for JSON schemas (needed custom config). Basic tracing config.	Structured logging with JSON formats (ECS, GELF, etc.) supported via properties. Enhanced tracing config (OTLP over gRPC, new trace export toggles), and new `spring.application.group` for log/trace grouping.
Actuator Endpoints	Endpoints either enabled or disabled; no intermediate access level. No built-in SSL cert info.	Read-only actuator mode for safer monitoring. New SSL certificate info via Actuator (shows expiring certs), plus richer `/scheduledtasks` details.
Testing & Containers	Limited Testcontainers auto-config (from 3.1, lacked some services). `@MockBean` and manual `MockMvc` usage.	Extended Testcontainers support (e.g. Redis, Kafka) simplifies integration tests. AssertJ-based `MockMvcTester` auto-configured. New `@MockitoBean` (Spring Framework 6.1+).
Cloud Integration	Larger default container images (Paketo base). ARM images required custom config.	Smaller images by default with Paketo `tiny` builder (faster startup). Multi-arch (ARM64) support. Docker Compose integration adds support for args and common env vars.
Messaging	ActiveMQ in-memory broker not auto-configured (had been removed). Basic Pulsar support.	ActiveMQ embedded broker auto-config is back (if `activemq-broker` is on classpath). Improved Pulsar support with new tuning and container customizer.
Dependency Versions	`Spring Framework 6.0/6.1`, `Spring Security 6.2`, etc. (older generations).	`Spring Framework 6.2`, `Spring Security 6.4`, `Spring Batch 5.2`, `Spring Data 2024.0`, `Hibernate 6.2`, etc. Aligns with 2025.0.0 Spring release train.

Notes: Even compared to Spring Boot 3.3, version 3.4.x is a minor release with major benefits. Upgrading within 3.x is far easier than the jump from 2.x to 3.x (which required Java 17 and Jakarta EE namespace changes), and the Spring team has provided upgrade instructions and release notes to smooth the process. Most applications can update to 3.4.5 with minimal code changes but immediately gain the improvements listed above.

Conclusion

Spring Boot 3.4.5 represents the state-of-the-art for Spring-based backend development as of 2025. It refines the developer experience, enhances observability, and strengthens integration with cloud platforms. By upgrading to 3.4.5, professional development teams can reap significant benefits:

Better performance under load (thanks to virtual threads and other optimizations),
Improved security by default (with the latest dependencies and more secure defaults),
Simplified cloud-native operations (with features aligning to container and microservice best practices).

In a world where efficient, secure, and scalable services are a must, Spring Boot 3.4.5 provides a robust foundation to build on. As the official Spring blog puts it, Spring Boot 3.4.0 “expands the possibilities for enterprise Java applications” and “pushes the boundaries of what these applications can achieve”. The 3.4.5 release builds on that foundation with additional polish (over 60 bug fixes and improvements) ensuring a smooth and reliable experience.

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