Spring Boot graceful shutdown

Graceful shutdown

Graceful shutdown is supported with all four embedded web servers (Jetty, Reactor Netty, Tomcat, and Undertow) and with both reactive and Servlet-based web applications. When enabled using server.shutdown=graceful, upon shutdown, the web server will no longer permit new requests and will wait for a grace period for active requests to complete. The grace period can be configured using spring.lifecycle.timeout-per-shutdown-phase. Please see the reference documentation for further details.

Spring Boot 2.3.0.RELEASE引入了Graceful Shutdown的功能。其中应用在等待下线期间对待新请求的方式，取决于我们所使用的 Server 类型。根据官方文档Tomcat、Jetty 和 Reactor Netty将会在网络层面停止接收新的请求。Undertow 会继续接收新的请求，但立即会以 HTTP 503（服务不可用）来响应。