Remove ServerHttpObservationFilter from WebFlux

This commit removes the auto-configuration of the
`ServerHttpObservationFilter` bean for WebFlux applications as it's been
deprecated by Spring Framework.

The Observability instrumentation is now handled at the
`WebHttpHandlerBuilder` in Framework directly and doesn't need any
auto-configuration from Spring Boot.

Closes gh-37344

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/observation/web/reactive/WebFluxObservationAutoConfiguration.java

@@ -21,9 +21,6 @@ import io.micrometer.core.instrument.config.MeterFilter;
 import io.micrometer.observation.Observation;
 import io.micrometer.observation.ObservationRegistry;
 
-import org.springframework.beans.factory.ObjectProvider;
-import org.springframework.boot.actuate.autoconfigure.metrics.CompositeMeterRegistryAutoConfiguration;
-import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.MetricsProperties;
 import org.springframework.boot.actuate.autoconfigure.metrics.OnlyOnceLoggingDenyMeterFilter;
 import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
@@ -33,16 +30,10 @@ import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
-import org.springframework.http.server.reactive.observation.DefaultServerRequestObservationConvention;
-import org.springframework.http.server.reactive.observation.ServerRequestObservationConvention;
-import org.springframework.web.filter.reactive.ServerHttpObservationFilter;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for instrumentation of Spring
@@ -53,48 +44,22 @@ import org.springframework.web.filter.reactive.ServerHttpObservationFilter;
  * @author Dmytro Nosan
  * @since 3.0.0
  */
-@AutoConfiguration(after = { MetricsAutoConfiguration.class, CompositeMeterRegistryAutoConfiguration.class,
+@AutoConfiguration(after = { SimpleMetricsExportAutoConfiguration.class, ObservationAutoConfiguration.class })
-		SimpleMetricsExportAutoConfiguration.class, ObservationAutoConfiguration.class })
+@ConditionalOnClass({ Observation.class, MeterRegistry.class })
-@ConditionalOnClass(Observation.class)
+@ConditionalOnBean({ ObservationRegistry.class, MeterRegistry.class })
-@ConditionalOnBean(ObservationRegistry.class)
 @ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.REACTIVE)
 @EnableConfigurationProperties({ MetricsProperties.class, ObservationProperties.class })
-@SuppressWarnings("removal")
 public class WebFluxObservationAutoConfiguration {
 
-	private final ObservationProperties observationProperties;
-
-	public WebFluxObservationAutoConfiguration(ObservationProperties observationProperties) {
-		this.observationProperties = observationProperties;
-	}
-
 	@Bean
-	@ConditionalOnMissingBean(ServerHttpObservationFilter.class)
+	@Order(0)
-	@Order(Ordered.HIGHEST_PRECEDENCE + 1)
+	MeterFilter metricsHttpServerUriTagFilter(MetricsProperties metricsProperties,
-	public ServerHttpObservationFilter webfluxObservationFilter(ObservationRegistry registry,
+			ObservationProperties observationProperties) {
-			ObjectProvider<ServerRequestObservationConvention> customConvention) {
+		String name = observationProperties.getHttp().getServer().getRequests().getName();
-		String name = this.observationProperties.getHttp().getServer().getRequests().getName();
+		MeterFilter filter = new OnlyOnceLoggingDenyMeterFilter(
-		ServerRequestObservationConvention convention = customConvention
+				() -> "Reached the maximum number of URI tags for '%s'.".formatted(name));
-			.getIfAvailable(() -> new DefaultServerRequestObservationConvention(name));
+		return MeterFilter.maximumAllowableTags(name, "uri", metricsProperties.getWeb().getServer().getMaxUriTags(),
-		return new ServerHttpObservationFilter(registry, convention);
+				filter);
-	}
-
-	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnClass(MeterRegistry.class)
-	@ConditionalOnBean(MeterRegistry.class)
-	static class MeterFilterConfiguration {
-
-		@Bean
-		@Order(0)
-		MeterFilter metricsHttpServerUriTagFilter(MetricsProperties metricsProperties,
-				ObservationProperties observationProperties) {
-			String name = observationProperties.getHttp().getServer().getRequests().getName();
-			MeterFilter filter = new OnlyOnceLoggingDenyMeterFilter(
-					() -> "Reached the maximum number of URI tags for '%s'.".formatted(name));
-			return MeterFilter.maximumAllowableTags(name, "uri", metricsProperties.getWeb().getServer().getMaxUriTags(),
-					filter);
-		}
-
 	}
 
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/observation/web/reactive/WebFluxObservationAutoConfigurationTests.java

@@ -16,12 +16,12 @@
 
 package org.springframework.boot.actuate.autoconfigure.observation.web.reactive;
 
-import java.util.List;
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
 
 import io.micrometer.core.instrument.MeterRegistry;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
-import reactor.core.publisher.Mono;
 
 import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.test.MetricsRun;
@@ -33,16 +33,6 @@ import org.springframework.boot.test.context.assertj.AssertableReactiveWebApplic
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
 import org.springframework.boot.test.system.CapturedOutput;
 import org.springframework.boot.test.system.OutputCaptureExtension;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.core.Ordered;
-import org.springframework.core.annotation.Order;
-import org.springframework.http.server.reactive.observation.DefaultServerRequestObservationConvention;
-import org.springframework.test.web.reactive.server.WebTestClient;
-import org.springframework.web.filter.reactive.ServerHttpObservationFilter;
-import org.springframework.web.server.ServerWebExchange;
-import org.springframework.web.server.WebFilter;
-import org.springframework.web.server.WebFilterChain;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -54,7 +44,6 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Madhura Bhave
  */
 @ExtendWith(OutputCaptureExtension.class)
-@SuppressWarnings("removal")
 class WebFluxObservationAutoConfigurationTests {
 
 	private final ReactiveWebApplicationContextRunner contextRunner = new ReactiveWebApplicationContextRunner()
@@ -62,31 +51,6 @@ class WebFluxObservationAutoConfigurationTests {
 		.withConfiguration(
 				AutoConfigurations.of(ObservationAutoConfiguration.class, WebFluxObservationAutoConfiguration.class));
 
-	@Test
-	void shouldProvideWebFluxObservationFilter() {
-		this.contextRunner.run((context) -> assertThat(context).hasSingleBean(ServerHttpObservationFilter.class));
-	}
-
-	@Test
-	void shouldProvideWebFluxObservationFilterOrdered() {
-		this.contextRunner.withBean(FirstWebFilter.class).withBean(ThirdWebFilter.class).run((context) -> {
-			List<WebFilter> webFilters = context.getBeanProvider(WebFilter.class).orderedStream().toList();
-			assertThat(webFilters.get(0)).isInstanceOf(FirstWebFilter.class);
-			assertThat(webFilters.get(1)).isInstanceOf(ServerHttpObservationFilter.class);
-			assertThat(webFilters.get(2)).isInstanceOf(ThirdWebFilter.class);
-		});
-	}
-
-	@Test
-	void shouldUseCustomConventionWhenAvailable() {
-		this.contextRunner.withUserConfiguration(CustomConventionConfiguration.class).run((context) -> {
-			assertThat(context).hasSingleBean(ServerHttpObservationFilter.class);
-			assertThat(context).getBean(ServerHttpObservationFilter.class)
-				.extracting("observationConvention")
-				.isInstanceOf(CustomConvention.class);
-		});
-	}
-
 	@Test
 	void afterMaxUrisReachedFurtherUrisAreDenied(CapturedOutput output) {
 		this.contextRunner.withUserConfiguration(TestController.class)
@@ -108,7 +72,7 @@ class WebFluxObservationAutoConfigurationTests {
 			.withPropertyValues("management.metrics.web.server.max-uri-tags=2",
 					"management.observations.http.server.requests.name=my.http.server.requests")
 			.run((context) -> {
-				MeterRegistry registry = getInitializedMeterRegistry(context);
+				MeterRegistry registry = getInitializedMeterRegistry(context, "my.http.server.requests");
 				assertThat(registry.get("my.http.server.requests").meters()).hasSizeLessThanOrEqualTo(2);
 				assertThat(output).contains("Reached the maximum number of URI tags for 'my.http.server.requests'");
 			});
@@ -127,53 +91,17 @@ class WebFluxObservationAutoConfigurationTests {
 			});
 	}
 
-	private MeterRegistry getInitializedMeterRegistry(AssertableReactiveWebApplicationContext context)
+	private MeterRegistry getInitializedMeterRegistry(AssertableReactiveWebApplicationContext context) {
-			throws Exception {
+		return getInitializedMeterRegistry(context, "http.server.requests");
-		return getInitializedMeterRegistry(context, "/test0", "/test1", "/test2");
 	}
 
-	private MeterRegistry getInitializedMeterRegistry(AssertableReactiveWebApplicationContext context, String... urls)
+	private MeterRegistry getInitializedMeterRegistry(AssertableReactiveWebApplicationContext context,
-			throws Exception {
+			String metricName) {
-		assertThat(context).hasSingleBean(ServerHttpObservationFilter.class);
+		MeterRegistry meterRegistry = context.getBean(MeterRegistry.class);
-		WebTestClient client = WebTestClient.bindToApplicationContext(context).build();
+		meterRegistry.timer(metricName, "uri", "/test0").record(Duration.of(500, ChronoUnit.SECONDS));
-		for (String url : urls) {
+		meterRegistry.timer(metricName, "uri", "/test1").record(Duration.of(500, ChronoUnit.SECONDS));
-			client.get().uri(url).exchange().expectStatus().isOk();
+		meterRegistry.timer(metricName, "uri", "/test2").record(Duration.of(500, ChronoUnit.SECONDS));
-		}
+		return meterRegistry;
-		return context.getBean(MeterRegistry.class);
-	}
-
-	@Configuration(proxyBeanMethods = false)
-	static class CustomConventionConfiguration {
-
-		@Bean
-		CustomConvention customConvention() {
-			return new CustomConvention();
-		}
-
-	}
-
-	static class CustomConvention extends DefaultServerRequestObservationConvention {
-
-	}
-
-	@Order(Ordered.HIGHEST_PRECEDENCE)
-	static class FirstWebFilter implements WebFilter {
-
-		@Override
-		public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
-			return chain.filter(exchange);
-		}
-
-	}
-
-	@Order(Ordered.HIGHEST_PRECEDENCE + 2)
-	static class ThirdWebFilter implements WebFilter {
-
-		@Override
-		public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
-			return chain.filter(exchange);
-		}
-
 	}
 
 }

spring-boot-project/spring-boot-docs/src/docs/asciidoc/web/reactive.adoc

@@ -245,9 +245,6 @@ When it does so, the orders shown in the following table will be used:
 |===
 | Web Filter | Order
 
-| `ServerHttpObservationFilter` (Micrometer Observability)
-| `Ordered.HIGHEST_PRECEDENCE + 1`
-
 | `WebFilterChainProxy` (Spring Security)
 | `-100`