Kubernetes Articles
5 articles about Kubernetes. Explore Spring Boot implementation, design, and operations across related topics.
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Why HikariCP Fails to Connect When Scaling Spring Boot to Multiple Replicas on Kubernetes - Reverse-Engineering maximumPoolSize from the DB's max_connections
This article explains why 'too many connections' errors occur when scaling out a Spring Boot application on Kubernetes, and describes a design approach for reverse-engineering the per-Pod HikariCP maximumPoolSize from the DB's max_connections and the number of replicas.
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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 Prevent Duplicate @Scheduled Execution in Distributed Environments with Spring Boot and ShedLock
Learn how to solve the @Scheduled duplicate execution problem that occurs when running multiple Pods on Kubernetes and similar platforms using ShedLock. Covers LockProvider configuration for both JDBC and Redis, correct usage of @SchedulerLock, and common pitfalls.
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How to Achieve Graceful Shutdown and Zero-Downtime Deployment in Spring Boot
A practical guide to combining graceful shutdown configuration in Spring Boot 2.3+ with Kubernetes preStop hooks to ensure zero-downtime deployments without dropping in-flight requests.
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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.