Port already in use
The root error Port already in use occurs when an application attempts to start a network service on a port that is already occupied by another running process. Because operating systems allow only one process to listen on a specific port and protocol combination at a time, this error is common in Linux servers, Windows systems, Java and Spring Boot applications, Docker containers, and database or web server environments. When does this error occur? When starting a server application while another process is already listening on the same port When a previously running service did not shut down cleanly and kept the port open When multiple applications are configured to use the same default port When a Docker container is still bound to a host port When system services occupy common ports such as 8080, 3306, or 5432 Root cause of Port already in use The Port already in use error is raised by the operating system’s networking stack. When a process binds to a TCP ...