Add Log Messages when Configuring Reactor Netty ConnectionProvider

sdk/core/azure-core-http-netty/src/main/java/com/azure/core/http/netty/NettyAsyncHttpClientBuilder.java

@@ -233,6 +233,18 @@ public com.azure.core.http.HttpClient build() {
      */
     public NettyAsyncHttpClientBuilder connectionProvider(ConnectionProvider connectionProvider) {
         // Enables overriding the default reactor-netty connection/channel pool.
+        if (connectionProvider != null) {
+            LOGGER.verbose("Setting ConnectionProvider for the Reactor Netty HttpClient. Please be aware of the "
+                + "differences in runtime behavior when creating a default Reactor Netty HttpClient vs an HttpClient"
+                + "with a specified ConnectionProvider. For more details see " 
+                + "https://aka.ms/azsdk/java/docs/configure-httpclient.");
+        }
+
+        this.connectionProvider = connectionProvider;
+        return this;
+    }
+
+    NettyAsyncHttpClientBuilder connectionProviderInternal(ConnectionProvider connectionProvider) {
         this.connectionProvider = connectionProvider;
         return this;
     }

sdk/core/azure-core-http-netty/src/main/java/com/azure/core/http/netty/NettyAsyncHttpClientProvider.java

@@ -7,6 +7,7 @@
 import com.azure.core.http.HttpClientProvider;
 import com.azure.core.util.Configuration;
 import com.azure.core.util.HttpClientOptions;
+import com.azure.core.util.logging.ClientLogger;
 import reactor.netty.resources.ConnectionProvider;
 
 /**
@@ -18,6 +19,8 @@ public final class NettyAsyncHttpClientProvider implements HttpClientProvider {
     private final boolean enableHttpClientSharing;
     private static final int DEFAULT_MAX_CONNECTIONS = 500;
 
+    private static final ClientLogger LOGGER = new ClientLogger(NettyAsyncHttpClientProvider.class);
+
     // Enum Singleton Pattern
     private enum GlobalNettyHttpClient {
         HTTP_CLIENT(new NettyAsyncHttpClientBuilder().build());
@@ -73,6 +76,8 @@ public HttpClient createInstance(HttpClientOptions clientOptions) {
         // Only configure the maximum connections if it has been set in the options.
         Integer maximumConnectionPoolSize = clientOptions.getMaximumConnectionPoolSize();
         if (maximumConnectionPoolSize != null && maximumConnectionPoolSize > 0) {
+            LOGGER.verbose("Setting Reactor Netty ConnectionProvider's maximum connections to "
+                + maximumConnectionPoolSize + ".");
             connectionProviderBuilder.maxConnections(maximumConnectionPoolSize);
         } else {
             // reactor-netty (as of version 1.0.13) uses different default values for maxConnections when creating
@@ -89,7 +94,7 @@ public HttpClient createInstance(HttpClientOptions clientOptions) {
             connectionProviderBuilder.maxConnections(DEFAULT_MAX_CONNECTIONS);
         }
 
-        builder = builder.connectionProvider(connectionProviderBuilder.build());
+        builder = builder.connectionProviderInternal(connectionProviderBuilder.build());
 
         return builder.build();
     }