Actuator Articles
7 articles about Actuator. Explore Spring Boot implementation, design, and operations across related topics.
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How to Tune Embedded Tomcat Thread Count in Spring Boot - Deciding server.tomcat.threads.max, max-connections, and accept-count
This article explains at which stage of request handling server.tomcat.threads.max, threads.min-spare, max-connections, and accept-count take effect in Spring Boot 3.x's embedded Tomcat, and walks through a procedure for choosing values with evidence using Actuator's tomcat.threads.* metrics and load testing. It also covers alignment with HikariCP's maximumPoolSize and the differences when Virtual Threads are enabled.
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How to Create Custom Health Checks (HealthIndicator) and Custom Actuator Endpoints in Spring Boot
Learn how to integrate the health status of dependencies such as external APIs, databases, and message brokers into your custom health using a custom HealthIndicator, assign them to readiness/liveness via health groups, and add custom operational Actuator endpoints with @Endpoint. Includes verification with curl.
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How to Speed Up Spring Boot Application Startup - Reducing Time with CDS, AOT, and Lazy Initialization
Spring Boot apps starting too slowly, causing Pods to miss readiness probes, or breaking your focus during local rebuilds—this guide solves those problems with practical steps. Learn how to identify bottlenecks with Actuator startup, then progressively apply lazy initialization, AutoConfig exclusion, CDS, and AOT to consistently reduce startup time.
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How to Correctly Configure and Tune the HikariCP Connection Pool in Spring Boot - Why the Default of 10 Isn't Enough
A tuning walkthrough for eliminating "Connection is not available" errors with HikariCP in Spring Boot. Covers the default maximumPoolSize of 10 and the official sizing formula (cores × 2 + 1), reducing connectionTimeout from 30s to 3s, the relationship between maxLifetime and wait_timeout, and leak detection with leakDetectionThreshold, all with implementation examples. Includes comparison data showing the timeout error rate dropping from 40% to 3% after revisiting the configuration.
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How to Deploy a Spring Boot Application to Kubernetes
A step-by-step guide to deploying a Dockerized Spring Boot application to Kubernetes. Covers creating Manifests for Deployment, Service, ConfigMap, and Secret, as well as configuring Actuator health endpoints as livenessProbe/readinessProbe — practical patterns you can use in production.
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Visualizing Spring Boot Metrics with Prometheus and Grafana
A hands-on guide to collecting Spring Boot application metrics in Prometheus via Micrometer and visualizing them in real time on Grafana dashboards. Also covers custom metrics implementation examples (Counter and Gauge) and security considerations for production operation.
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Getting Started with Spring Boot Actuator
A practical guide covering everything from introducing spring-boot-starter-actuator, configuring health/info/metrics endpoint exposure, a minimal application.yml, Prometheus integration, to secure production-ready exposure configurations. A gentle summary for those touching Spring Boot Actuator for the first time.