feat: enable TcpClient metrics

r2dbc-mysql/src/main/java/io/asyncer/r2dbc/mysql/MySqlConnectionConfiguration.java

@@ -25,6 +25,7 @@
 import io.netty.resolver.AddressResolverGroup;
 import org.jetbrains.annotations.Nullable;
 import org.reactivestreams.Publisher;
+import reactor.netty.internal.util.Metrics;
 import reactor.netty.resources.LoopResources;
 import reactor.netty.tcp.TcpResources;
 
@@ -131,6 +132,8 @@ public final class MySqlConnectionConfiguration {
     @Nullable
     private final AddressResolverGroup<?> resolver;
 
+    private final boolean metrics;
+
     private MySqlConnectionConfiguration(
         boolean isHost, String domain, int port, MySqlSslConfiguration ssl,
         boolean tcpKeepAlive, boolean tcpNoDelay, @Nullable Duration connectTimeout,
@@ -146,7 +149,8 @@ private MySqlConnectionConfiguration(
         Set<CompressionAlgorithm> compressionAlgorithms, int zstdCompressionLevel,
         @Nullable LoopResources loopResources,
         Extensions extensions, @Nullable Publisher<String> passwordPublisher,
-        @Nullable AddressResolverGroup<?> resolver
+        @Nullable AddressResolverGroup<?> resolver,
+        boolean metrics
     ) {
         this.isHost = isHost;
         this.domain = domain;
@@ -177,6 +181,7 @@ private MySqlConnectionConfiguration(
         this.extensions = extensions;
         this.passwordPublisher = passwordPublisher;
         this.resolver = resolver;
+        this.metrics = metrics;
     }
 
     /**
@@ -312,6 +317,10 @@ AddressResolverGroup<?> getResolver() {
         return resolver;
     }
 
+    boolean isMetrics() {
+        return metrics;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) {
@@ -349,7 +358,8 @@ public boolean equals(Object o) {
             Objects.equals(loopResources, that.loopResources) &&
             extensions.equals(that.extensions) &&
             Objects.equals(passwordPublisher, that.passwordPublisher) &&
-            Objects.equals(resolver, that.resolver);
+            Objects.equals(resolver, that.resolver) &&
+            metrics == that.metrics;
     }
 
     @Override
@@ -364,7 +374,7 @@ public int hashCode() {
             loadLocalInfilePath, localInfileBufferSize,
             queryCacheSize, prepareCacheSize,
             compressionAlgorithms, zstdCompressionLevel,
-            loopResources, extensions, passwordPublisher, resolver);
+            loopResources, extensions, passwordPublisher, resolver, metrics);
     }
 
     @Override
@@ -398,7 +408,8 @@ private String buildCommonToStringPart() {
                 ", loopResources=" + loopResources +
                 ", extensions=" + extensions +
                 ", passwordPublisher=" + passwordPublisher +
-                ", resolver=" + resolver;
+                ", resolver=" + resolver +
+                ", metrics=" + metrics;
     }
 
     /**
@@ -498,6 +509,8 @@ public static final class Builder {
         @Nullable
         private AddressResolverGroup<?> resolver;
 
+        private boolean metrics;
+
         /**
          * Builds an immutable {@link MySqlConnectionConfiguration} with current options.
          *
@@ -532,7 +545,7 @@ public MySqlConnectionConfiguration build() {
                 loadLocalInfilePath,
                 localInfileBufferSize, queryCacheSize, prepareCacheSize,
                 compressionAlgorithms, zstdCompressionLevel, loopResources,
-                Extensions.from(extensions, autodetectExtensions), passwordPublisher, resolver);
+                Extensions.from(extensions, autodetectExtensions), passwordPublisher, resolver, metrics);
         }
 
         /**
@@ -1175,6 +1188,25 @@ public Builder resolver(AddressResolverGroup<?> resolver) {
             return this;
         }
 
+        /**
+         * Option to enable metrics to be collected and registered in Micrometer's globalRegistry
+         * with {@link reactor.netty.tcp.TcpClient#metrics(boolean)}. Defaults to {@code false}.
+         * <p>
+         * Note: It is required to add {@code io.micrometer.micrometer-core} dependency to classpath.
+         *
+         * @param enabled enable metrics for {@link reactor.netty.tcp.TcpClient}.
+         * @return this {@link Builder}
+         * @throws IllegalArgumentException if {@code io.micrometer:micrometer-core} is not on the classpath.
+         * @since 1.3.2
+         */
+        public Builder metrics(boolean enabled) {
+            require(!enabled || Metrics.isMicrometerAvailable(),
+            "dependency `io.micrometer:micrometer-core` must be added to classpath if metrics enabled"
+            );
+            this.metrics = enabled;
+            return this;
+        }
+
         private SslMode requireSslMode() {
             SslMode sslMode = this.sslMode;
 

r2dbc-mysql/src/main/java/io/asyncer/r2dbc/mysql/MySqlConnectionFactory.java

@@ -148,7 +148,8 @@ private static Mono<MySqlConnection> getMySqlConnection(
             context,
             configuration.getConnectTimeout(),
             configuration.getLoopResources(),
-            configuration.getResolver()
+            configuration.getResolver(),
+            configuration.isMetrics()
         )).flatMap(client -> {
             // Lazy init database after handshake/login
             boolean deferDatabase = configuration.isCreateDatabaseIfNotExist();

r2dbc-mysql/src/main/java/io/asyncer/r2dbc/mysql/MySqlConnectionFactoryProvider.java

@@ -320,6 +320,16 @@ public final class MySqlConnectionFactoryProvider implements ConnectionFactoryPr
      */
     public static final Option<AddressResolverGroup<?>> RESOLVER = Option.valueOf("resolver");
 
+    /**
+     * Option to enable metrics to be collected and registered in Micrometer's globalRegistry
+     * with {@link reactor.netty.tcp.TcpClient#metrics(boolean)}. Defaults to {@code false}.
+     * <p>
+     * Note: It is required to add {@code io.micrometer.micrometer-core} dependency to classpath.
+     *
+     * @since 1.3.2
+     */
+    public static final Option<Boolean> METRICS = Option.valueOf("metrics");
+
     @Override
     public ConnectionFactory create(ConnectionFactoryOptions options) {
         requireNonNull(options, "connectionFactoryOptions must not be null");
@@ -413,6 +423,8 @@ static MySqlConnectionConfiguration setup(ConnectionFactoryOptions options) {
             .to(builder::lockWaitTimeout);
         mapper.optional(STATEMENT_TIMEOUT).as(Duration.class, Duration::parse)
             .to(builder::statementTimeout);
+        mapper.optional(METRICS).asBoolean()
+            .to(builder::metrics);
 
         return builder.build();
     }

r2dbc-mysql/src/main/java/io/asyncer/r2dbc/mysql/client/Client.java

@@ -127,19 +127,21 @@ public interface Client {
      * @param context        the connection context
      * @param connectTimeout connect timeout, or {@code null} if it has no timeout
      * @param loopResources  the loop resources to use
+     * @param metrics        if enable the {@link TcpClient#metrics)}
      * @return A {@link Mono} that will emit a connected {@link Client}.
      * @throws IllegalArgumentException if {@code ssl}, {@code address} or {@code context} is {@code null}.
      * @throws ArithmeticException      if {@code connectTimeout} milliseconds overflow as an int
      */
     static Mono<Client> connect(MySqlSslConfiguration ssl, SocketAddress address, boolean tcpKeepAlive,
         boolean tcpNoDelay, ConnectionContext context, @Nullable Duration connectTimeout,
-        LoopResources loopResources, @Nullable AddressResolverGroup<?> resolver) {
+        LoopResources loopResources, @Nullable AddressResolverGroup<?> resolver, boolean metrics) {
         requireNonNull(ssl, "ssl must not be null");
         requireNonNull(address, "address must not be null");
         requireNonNull(context, "context must not be null");
 
         TcpClient tcpClient = TcpClient.newConnection()
-            .runOn(loopResources);
+            .runOn(loopResources)
+            .metrics(metrics);
 
         if (connectTimeout != null) {
             tcpClient = tcpClient.option(ChannelOption.CONNECT_TIMEOUT_MILLIS,

r2dbc-mysql/src/test/java/io/asyncer/r2dbc/mysql/MySqlConnectionConfigurationTest.java

@@ -222,6 +222,19 @@ void validResolver() {
         assertThat(resolverGroup).isSameAs(resolver);
     }
 
+    @Test
+    void invalidMetrics() {
+        // throw exception when metrics true without micrometer-core dependency
+        assertThatIllegalArgumentException().isThrownBy(() ->
+            MySqlConnectionConfiguration
+                .builder()
+                .host(HOST)
+                .user(USER)
+                .metrics(true)
+                .build()
+        );
+    }
+
     private static MySqlConnectionConfiguration unixSocketSslMode(SslMode sslMode) {
         return MySqlConnectionConfiguration.builder()
             .unixSocket(UNIX_SOCKET)

r2dbc-mysql/src/test/java/io/asyncer/r2dbc/mysql/MySqlConnectionFactoryProviderTest.java

@@ -51,6 +51,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import static io.asyncer.r2dbc.mysql.MySqlConnectionFactoryProvider.METRICS;
 import static io.asyncer.r2dbc.mysql.MySqlConnectionFactoryProvider.PASSWORD_PUBLISHER;
 import static io.asyncer.r2dbc.mysql.MySqlConnectionFactoryProvider.RESOLVER;
 import static io.asyncer.r2dbc.mysql.MySqlConnectionFactoryProvider.USE_SERVER_PREPARE_STATEMENT;
@@ -469,6 +470,18 @@ void validResolver() {
         assertThat(ConnectionFactories.get(options)).isExactlyInstanceOf(MySqlConnectionFactory.class);
     }
 
+    @Test
+    void invalidMetrics() {
+        // throw exception when metrics true without micrometer-core dependency
+        assertThatIllegalArgumentException().isThrownBy(() ->
+            ConnectionFactories.get(ConnectionFactoryOptions.builder()
+                .option(DRIVER, "mysql")
+                .option(HOST, "127.0.0.1")
+                .option(USER, "root")
+                .option(METRICS, true)
+                .build()));
+    }
+
     @Test
     void allConfigurationOptions() {
         List<String> exceptConfigs = Arrays.asList(