Use SmartLifecycle for graceful web server shutdown

Closes gh-21325

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -100,6 +100,11 @@ public class ServerProperties {
 	 */
 	private DataSize maxHttpHeaderSize = DataSize.ofKilobytes(8);
 
+	/**
+	 * Type of shutdown that the server will support.
+	 */
+	private Shutdown shutdown = Shutdown.IMMEDIATE;
+
 	@NestedConfigurationProperty
 	private Ssl ssl;
 
@@ -109,9 +114,6 @@ public class ServerProperties {
 	@NestedConfigurationProperty
 	private final Http2 http2 = new Http2();
 
-	@NestedConfigurationProperty
-	private final Shutdown shutdown = new Shutdown();
-
 	private final Servlet servlet = new Servlet();
 
 	private final Tomcat tomcat = new Tomcat();
@@ -154,6 +156,14 @@ public void setMaxHttpHeaderSize(DataSize maxHttpHeaderSize) {
 		this.maxHttpHeaderSize = maxHttpHeaderSize;
 	}
 
+	public Shutdown getShutdown() {
+		return this.shutdown;
+	}
+
+	public void setShutdown(Shutdown shutdown) {
+		this.shutdown = shutdown;
+	}
+
 	public ErrorProperties getError() {
 		return this.error;
 	}
@@ -174,10 +184,6 @@ public Http2 getHttp2() {
 		return this.http2;
 	}
 
-	public Shutdown getShutdown() {
-		return this.shutdown;
-	}
-
 	public Servlet getServlet() {
 		return this.servlet;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -266,6 +266,9 @@
       "name": "server.ssl.trust-store-type",
       "description": "Type of the trust store."
     },
+    { "name": "server.shutdown",
+      "defaultValue:": "immediate"
+    },
     {
       "name": "server.tomcat.max-http-post-size",
       "type": "org.springframework.util.unit.DataSize",

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/ReactiveWebServerFactoryCustomizerTests.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.autoconfigure.web.reactive;
 
 import java.net.InetAddress;
-import java.time.Duration;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -76,13 +75,13 @@ void testCustomizeServerSsl() {
 	}
 
 	@Test
-	void whenGracePeriodPropertyIsSetThenGracePeriodIsCustomized() {
-		this.properties.getShutdown().setGracePeriod(Duration.ofSeconds(30));
+	void whenShutdownPropertyIsSetThenShutdownIsCustomized() {
+		this.properties.setShutdown(Shutdown.GRACEFUL);
 		ConfigurableReactiveWebServerFactory factory = mock(ConfigurableReactiveWebServerFactory.class);
 		this.customizer.customize(factory);
 		ArgumentCaptor<Shutdown> shutdownCaptor = ArgumentCaptor.forClass(Shutdown.class);
 		verify(factory).setShutdown(shutdownCaptor.capture());
-		assertThat(shutdownCaptor.getValue().getGracePeriod()).isEqualTo(Duration.ofSeconds(30));
+		assertThat(shutdownCaptor.getValue()).isEqualTo(Shutdown.GRACEFUL);
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/ServletWebServerFactoryCustomizerTests.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.autoconfigure.web.servlet;
 
 import java.io.File;
-import java.time.Duration;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -165,15 +164,15 @@ void sessionStoreDir() {
 	}
 
 	@Test
-	void whenGracePeriodPropertyIsSetThenGracePeriodIsCustomized() {
+	void whenShutdownPropertyIsSetThenShutdownIsCustomized() {
 		Map<String, String> map = new HashMap<>();
-		map.put("server.shutdown.grace-period", "30s");
+		map.put("server.shutdown", "graceful");
 		bindProperties(map);
 		ConfigurableServletWebServerFactory factory = mock(ConfigurableServletWebServerFactory.class);
 		this.customizer.customize(factory);
 		ArgumentCaptor<Shutdown> shutdownCaptor = ArgumentCaptor.forClass(Shutdown.class);
 		verify(factory).setShutdown(shutdownCaptor.capture());
-		assertThat(shutdownCaptor.getValue().getGracePeriod()).isEqualTo(Duration.ofSeconds(30));
+		assertThat(shutdownCaptor.getValue()).isEqualTo(Shutdown.GRACEFUL);
 	}
 
 	private void bindProperties(Map<String, String> map) {

spring-boot-project/spring-boot-docs/src/docs/asciidoc/spring-boot-features.adoc

@@ -3145,21 +3145,19 @@ You can learn more about the resource configuration on the client side in the <<
 [[boot-features-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, shutdown of the application will include a grace period of configurable duration.
-During this grace period, existing requests will be allowed to complete but no new requests will be permitted.
+It occurs as part of closing the application context and is performed in the earliest phase of stopping `SmartLifecycle` beans.
+This stop processing uses a timeout which provides a grace period during which existing requests will be allowed to complete but no new requests will be permitted.
 The exact way in which new requests are not permitted varies depending on the web server that is being used.
 Jetty, Reactor Netty, and Tomcat will stop accepting requests at the network layer.
 Undertow will accept requests but respond immediately with a service unavailable (503) response.
 
 NOTE: Graceful shutdown with Tomcat requires Tomcat 9.0.33 or later.
 
-Graceful shutdown occurs as one of the first steps during application close processing and before any beans have been destroyed.
-This ensures that the beans are available for use by any processing that occurs while in-flight requests are being allowed to complete.
-To enable graceful shutdown, configure the configprop:server.shutdown.grace-period[] property, as shown in the following example:
+To enable graceful shutdown, configure the configprop:server.shutdown[] property, as shown in the following example:
 
 [source,properties,indent=0,configprops]
 ----
-server.shutdown.grace-period=30s
+server.shutdown=graceful
 ----
 
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyGracefulShutdown.java

@@ -32,12 +32,14 @@
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.server.handler.HandlerWrapper;
+import org.eclipse.jetty.server.handler.StatisticsHandler;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
 import org.eclipse.jetty.util.thread.ThreadPool;
 
 import org.springframework.boot.web.reactive.server.AbstractReactiveWebServerFactory;
 import org.springframework.boot.web.reactive.server.ReactiveWebServerFactory;
+import org.springframework.boot.web.server.Shutdown;
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.http.client.reactive.JettyResourceFactory;
 import org.springframework.http.server.reactive.HttpHandler;
@@ -103,7 +105,7 @@ public void setAcceptors(int acceptors) {
 	public WebServer getWebServer(HttpHandler httpHandler) {
 		JettyHttpHandlerAdapter servlet = new JettyHttpHandlerAdapter(httpHandler);
 		Server server = createJettyServer(servlet);
-		return new JettyWebServer(server, getPort() >= 0, getShutdown().getGracePeriod());
+		return new JettyWebServer(server, getPort() >= 0);
 	}
 
 	@Override
@@ -182,6 +184,11 @@ protected Server createJettyServer(JettyHttpHandlerAdapter servlet) {
 		if (this.useForwardHeaders) {
 			new ForwardHeadersCustomizer().customize(server);
 		}
+		if (getShutdown() == Shutdown.GRACEFUL) {
+			StatisticsHandler statisticsHandler = new StatisticsHandler();
+			statisticsHandler.setHandler(server.getHandler());
+			server.setHandler(statisticsHandler);
+		}
 		return server;
 	}
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyReactiveWebServerFactory.java

@@ -41,6 +41,7 @@
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.HandlerWrapper;
+import org.eclipse.jetty.server.handler.StatisticsHandler;
 import org.eclipse.jetty.server.session.DefaultSessionCache;
 import org.eclipse.jetty.server.session.FileSessionDataStore;
 import org.eclipse.jetty.server.session.SessionHandler;
@@ -57,6 +58,7 @@
 
 import org.springframework.boot.web.server.ErrorPage;
 import org.springframework.boot.web.server.MimeMappings;
+import org.springframework.boot.web.server.Shutdown;
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.boot.web.servlet.ServletContextInitializer;
 import org.springframework.boot.web.servlet.server.AbstractServletWebServerFactory;
@@ -152,6 +154,11 @@ public WebServer getWebServer(ServletContextInitializer... initializers) {
 		if (this.useForwardHeaders) {
 			new ForwardHeadersCustomizer().customize(server);
 		}
+		if (getShutdown() == Shutdown.GRACEFUL) {
+			StatisticsHandler statisticsHandler = new StatisticsHandler();
+			statisticsHandler.setHandler(server.getHandler());
+			server.setHandler(statisticsHandler);
+		}
 		return getJettyWebServer(server);
 	}
 
@@ -398,7 +405,7 @@ protected void postProcessWebAppContext(WebAppContext webAppContext) {
 	 * @return a new {@link JettyWebServer} instance
 	 */
 	protected JettyWebServer getJettyWebServer(Server server) {
-		return new JettyWebServer(server, getPort() >= 0, getShutdown().getGracePeriod());
+		return new JettyWebServer(server, getPort() >= 0);
 	}
 
 	@Override