2026-04-15 Spring IO - I Can See Clearly Now

Transcript

1. 2026-04-15 Jonatan Ivanov & Tommy Ludwig I Can See Clearly Now Observability of JVM & Spring Boot 2-3-4 apps
2. Spring Team/Micrometer Jonatan Ivanov Tommy Ludwig
3. Observability Basics
4. What is Observability? How well we can understand the internals of a system based on its outputs (Providing meaningful information about what happens inside) (Data about your app)
5. Why do we need Observability? Today's systems are increasingly complex (cloud) (Death Star Architecture, Big Ball of Mud)
6. Environments can be chaotic You turn a knob here a little and apps are going down there We need to deal with unknown unknowns We can’t know everything Things can be perceived differently by observers Everything is broken for the users but seems ok to you Why do we need Observability?
7. DEMO 🍵 github.com/jonatan-ivanov/teahouse
8. Tea Service 💻 Tealeaf Service Water Service Architecture Tealeaf DB Water DB
10. through traces TraceID ❮ Exemplars Tags ❯ metrics logs traces
11. Observability with Spring Boot 2.7
12. Migrate to Spring Boot 3.5
13. spring.io/projects/spring-boot#support
15. Observability with Spring Boot 3.5
16. Migrate to Spring Boot 4.x
17. Logging with Spring Boot (2.7, 3.5, 4.x)
18. SLF4J with Logback comes pre-configured SLF4J (Simple Logging Façade for Java) Simple API for logging libraries Logback Natively implements the SLF4J API If you want Log4j2 instead of Logback: - spring-boot-starter-logging + spring-boot-starter-log4j2 Logging: SLF4J + Logback
19. Logging: Payload, Access, GC Payload logs: Logbook + org.zalando:logbook-spring-boot-starter + org.zalando:logbook-* (httpclient5) Access logs: server.tomcat.accesslog.enabled=true server.jetty.accesslog.enabled=true server.undertow.accesslog.enabled=true (+ ch.qos.logback.access:logback-access-*) GC logs: JVM args
20. Metrics with Spring Boot (2.7, 3.5, 4.x)
21. Metrics: Micrometer Dimensional Metrics library on the JVM Like SLF4J, but for metrics API is independent of the configured metrics backend Supports many backends Comes with spring-boot-actuator Spring projects are instrumented using Micrometer Many third-party libraries use Micrometer
22. Supported metrics backends/formats/protocols Ganglia Graphite Humio InfluxDB JMX KairosDB New Relic (/actuator/metrics) OpenTSDB OTLP Prometheus SignalFx Stackdriver (GCP) StatsD Wavefront (VMware) AppOptics Atlas Azure Monitor CloudWatch (AWS) Datadog Dynatrace Elastic
23. org.springframework.boot: spring-boot-starter-actuator io.micrometer: micrometer-registry-prometheus Metrics
24. spring-boot-starter-actuator OR spring-boot-starter-micrometer- metrics (+ micrometer-registry-*) Metrics with Spring Boot 4.x
25. Tracing with Spring Boot (2.7, 3.5, 4.x)
26. Distributed Tracing with Spring Boot 2.7 Spring Cloud Sleuth Provides an abstraction layer on top of tracing libraries - Brave (OpenZipkin), “default” - OpenTelemetry (CNCF), “experimental” Instrumentation for Spring Projects, 3rd party libraries, your app Support for various backends
27. Distributed Tracing with Spring Boot 3.5 Micrometer Tracing (Sleuth w/o Spring dependencies) Provides an abstraction layer on top of tracing libraries - Brave (OpenZipkin), “default” - OpenTelemetry (CNCF), “experimental” Instrumentation for Spring Projects, 3rd party libraries, your app Support for various backends
28. Distributed Tracing with Spring Boot 3.5 (Brave) org.springframework.boot: spring-boot-starter-actuator io.micrometer: micrometer-tracing-bridge-brave io.zipkin.reporter2: zipkin-reporter-brave
29. Distributed Tracing with Spring Boot 3.5 (OTel) org.springframework.boot: spring-boot-starter-actuator io.micrometer: micrometer-tracing-bridge-otel io.opentelemetry: opentelemetry-exporter-otlp
30. spring-boot-starter-zipkin OR spring-boot-starter-opentelemetry (includes micrometer-registry-otlp) Distributed Tracing with Spring Boot 4.x
31. spring-boot- micrometer-tracing-brave micrometer-tracing-opentelemetry (+ bridge and a reporter/exporter) Distributed Tracing with Spring Boot 4.x
32. OpenTelemetry with Spring Boot 4.x OpenTelemetry with Spring Boot Blog post spring.io/blog/2025/11/18/opentelemetry-with-spring-boot start.spring.io => “OpenTelemetry” Logging The OTel Logback/Log4J appenders are not stable
33. Read the Docs docs.spring.io/spring-boot docs.spring.io/spring-boot/3.5 docs.spring.io/spring-boot/docs/2.7.x/reference start.spring.io (3.5 and 4.x) Boot 4.0 Migration Guide
34. Observation API
35. • Add Logs (application logs) • Add Metrics • Add Distributed Tracing You want to instrument your application…
36. Introducing Observation API • Since Micrometer 1.10 / Boot 3.0 (micrometer-observation) micrometer-core has a dependency on it • Higher level abstraction than metrics or tracing for timing an operation • Instrument once, configure handlers for multiple purposes (e.g.: metrics, tracing, logging, etc.) • Already used for most instrumentation shown
37. Observation API basic usage example Observation observation = Observation.start("talk",registry); try { // TODO: openScope() return getSomething(); // ← This is what we’re observing } catch (Exception exception) { observation.error(exception); throw exception; } finally { // TODO: attach tags (key-value) observation.stop(); }
38. Configuring an ObservationHandler (without Boot) ObservationRegistry registry = ObservationRegistry.create(); registry.observationConfig() .observationHandler(new MetricsHandler(...)) .observationHandler(new TracingHandler(...)) .observationHandler(new LoggingHandler(...)) .observationHandler(new AuditEventHandler(...));
39. ObservationHandler with Spring Boot Spring Boot auto-configures handlers for meters and tracing. Boot will also register ObservationHandler beans to the ObservationRegistry that it auto-configures. @Bean ObservationHandler<MyContext> myHandler() { return new MyObservationHandler(); }
40. Observation API shortcuts Observation.createNotStarted("talk",registry) .lowCardinalityKeyValue("event", "SIO") .highCardinalityKeyValue("uid", userId) .observe(this::talk);
41. Observation API shortcuts @Observed(...) @ObservationKeyValue(...) String email(@ObservationKeyValue(...) String id)
42. What’s ~new? • @MeterTag, @ObservationKeyValue • OtlpMetricsSender • More support for Virtual Threads • Jakarta Mail instrumentation • JSpecify • MeterConvention + OTel semantic conventions • Same name, different set of tag keys (Prometheus) • Exemplars support for OTLP
43. What’s ~new? • Spring Boot modularization ◦ OpenTelemetry starter ◦ Zipkin starter • Spring AI enhancements • SslInfo + Health improvements • SSL Bundle Metrics • ProcessInfo enhancements
44. Thank you! slack.micrometer.io #springio2026 GH: jonatan-ivanov/teahouse