Spring Boot Thread Starvation Explained Visually | Why Every Service Needs a Timeout | Microservices

In this video, we simulate a real-world production issue where a slow downstream service causes a Spring Boot application to become completely unresponsive. Using Spring Boot, WebClient, Prometheus, Grafana, and JMeter, we will visualize how missing timeouts can lead to Tomcat thread exhaustion and thread starvation. What you'll learn: What Thread Starvation is Why slow downstream dependencies can impact your application How missing timeouts affect Tomcat worker threads Monitoring response times and thread utilization using Grafana Why health checks and metrics endpoints may stop responding How adding a timeout helps keep the application responsive Tech Stack: Spring Boot WebClient Micrometer Prometheus Grafana Apache JMeter Video Chapters: 00:00 Introduction 00:13 Project Setup Overview 03:12 Important Metrics and Grafana Dashbaord 05:14 JMeter Test Setup Overview 07:45 Healthy External Service Without a Timeout 09:42 Slow External Service Without a Timeout 11:37 Thread Starvation 12:54 Application Becomes Unresponsive 16:00 Adding Timeout 18:02 Application Remains Responsive (No Thread Starvation) 18:52 Closing Comments Key Takeaway: Never do anything in life or code without a timeout. #SpringBoot #Java #Microservices #Prometheus #Grafana #Micrometer #JMeter #PerformanceTesting #ThreadStarvation #WebClient #BackendEngineering #JavaPerformance #Observability #ProductionDebugging