Application Yml Articles
5 articles about Application Yml. Explore Spring Boot implementation, design, and operations across related topics.
-
How to Split and Externalize Configuration Files with Spring Boot's spring.config.import
Explains how to use spring.config.import, available in the Config Data API since Spring Boot 2.4, with code examples covering the use of optional:, choosing between classpath:/file:, the load order priority of multiple files, and externalizing secret files.
-
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.
-
How to Connect Spring Boot to MySQL - application.yml Configuration, JDBC URL Parameters, and Time Zone/Character Encoding Pitfalls
A step-by-step guide to connecting Spring Boot 3.x to MySQL 8, covering Docker Compose startup, application.yml configuration, and connectivity checks. Also covers recommended JDBC URL parameter values and how to fix the Public Key Retrieval error, date/time offsets, and utf8mb4 garbled characters.
-
How to Properly Configure and Tune HikariCP Connection Pool in Spring Boot - Why the Default of 10 Isn't Enough
A tuning guide to eliminate Connection is not available errors in Spring Boot's HikariCP. Covers the maximumPoolSize default of 10 versus the official formula (cores × 2 + 1), revisiting connectionTimeout from 30 seconds to 3 seconds, the relationship between maxLifetime and wait_timeout, and leak detection with leakDetectionThreshold, all with implementation examples. Includes comparative data showing how configuration review reduced the timeout error rate from 40% to 3%.
-
How to Encrypt Sensitive Information in Configuration Files Using Jasypt with Spring Boot
If you're concerned about storing database passwords and API keys in plain text in application.yml, Jasypt is an easy solution. This guide covers the full implementation process for production use, from encryption steps using the ENC() wrapper to integration with environment variables and CI.