Silence peer closed warning logs

Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>

Author: chemicL

mcp-core/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java

@@ -164,6 +164,9 @@ else if (message instanceof McpSchema.JSONRPCRequest request) {
 				if (t instanceof McpTransportSessionClosedException) {
 					logger.debug("Can't send response to request {} when the transport is closed", request.id());
 				}
+				else if (McpTransport.isPeerClosed(t)) {
+					logger.debug("Can't send response to request {}: connection closed by peer", request.id(), t);
+				}
 				else {
 					logger.warn("Failed to send response to the server", t);
 				}

mcp-core/src/main/java/io/modelcontextprotocol/spec/McpTransport.java

@@ -53,7 +53,23 @@ public interface McpTransport {
 	 */
 	default void close() {
 		this.closeGracefully().subscribe(ignored -> {
-		}, error -> logger.warn("Error during asynchronous close", error));
+		}, error -> {
+			if (isPeerClosed(error)) {
+				logger.debug("Error during asynchronous close", error);
+			}
+			else {
+				logger.warn("Error during asynchronous close", error);
+			}
+		});
+	}
+
+	static boolean isPeerClosed(Throwable t) {
+		for (Throwable c = t; c != null; c = c.getCause()) {
+			if (c instanceof java.io.EOFException) {
+				return true;
+			}
+		}
+		return false;
 	}
 
 	/**

mcp-test/src/test/java/io/modelcontextprotocol/server/transport/ServerTransportSecurityIntegrationTests.java

@@ -81,6 +81,7 @@ void setUp() {
 
 	@AfterEach
 	void tearDown() {
+		requestCustomizer.reset();
 		mcpClient.close();
 	}