This article breaks down the interview question "Can TCP and UDP use the same port?" by examining protocol-level port spaces, client‑side TCP and UDP port sharing rules, server‑side TCP reuse with SO_REUSEADDR, and UDP reuse with SO_REUSEPORT, complete with code examples and practical implications.
This article explains why TCP and UDP can use the same numeric port, how client and server processes manage port sharing, and the role of socket options like SO_REUSEADDR and SO_REUSEPORT in enabling high‑availability and load‑balanced networking.
When updating a SpringBoot application the old process must be stopped because the new one cannot bind to the same port, but by leveraging Tomcat's embedded container, ServletWebServerFactory, and dynamic port handling you can keep both processes alive and achieve zero‑downtime deployments.
This article explains how to achieve seamless code updates for SpringBoot applications by allowing two instances to share the same port, detailing the underlying Tomcat embedding mechanism, DispatcherServlet handling, and providing a complete Java implementation with step‑by‑step instructions and test results.
This article explains how to enable two SpringBoot processes to share the same port for seamless code updates, covering the underlying servlet container mechanics, the required initialization flow, and providing a complete Java implementation with a demo that achieves near‑zero downtime during deployment.
