Increase default keepAliveTimeout to 60s and warn on legacy 5s usage

Author: pras529

doc/api/http.md

@@ -1940,6 +1940,9 @@ added: v8.0.0
 
 * Type: {number} Timeout in milliseconds. **Default:** `5000` (5 seconds).
 
+> **Note:** As of Node.js v24.0.0, the default value for `http.Server.keepAliveTimeout` is **60000ms (60s)**. Previous versions used **5000ms (5s)**. This aligns Node.js with browsers, proxies, and mobile clients, and avoids subtle connection failures. If your infrastructure expects the old value, set it explicitly. See [issue #59193](https://github.com/nodejs/node/issues/59193).
+
+
 The number of milliseconds of inactivity a server needs to wait for additional
 incoming data, after it has finished writing the last response, before a socket
 will be destroyed. If the server receives new data before the keep-alive

doc/changelogs/CHANGELOG_V24.md

@@ -624,6 +624,10 @@ latest release and evaluate their potential impact on your applications.
 
 ## Notable Changes
 
+### Breaking Changes
+- **http:** Changed the default value of `http.Server.keepAliveTimeout` from **5000ms (5s)** to **60000ms (60s)**. This prevents subtle long-connection failures due to premature socket closure, aligning with industry norms (browsers, proxies, mobile clients). See [issue #59193](https://github.com/nodejs/node/issues/59193).
+
+
 ### V8 13.6
 
 The V8 engine is updated to version 13.6, which includes several new

lib/_http_server.js

@@ -478,10 +478,24 @@ function storeHTTPOptions(options) {
 
   const keepAliveTimeout = options.keepAliveTimeout;
   if (keepAliveTimeout !== undefined) {
-    validateInteger(keepAliveTimeout, 'keepAliveTimeout', 0);
-    this.keepAliveTimeout = keepAliveTimeout;
+   validateInteger(keepAliveTimeout, 'keepAliveTimeout', 0);
+   this.keepAliveTimeout = keepAliveTimeout;
+   if (keepAliveTimeout === 5000) {
+     process.emitWarning(
+       'You are explicitly setting http.Server.keepAliveTimeout to 5000ms (5s), which was the legacy default. ' +
+       'This value is shorter than most industry infrastructure expects and can cause subtle connection failures. ' +
+       'It is recommended to use a higher value, such as 60000ms (60s). See: https://github.com/nodejs/node/issues/59193',
+       { code: 'LEGACY_KEEPALIVETIMEOUT', detail: 'Consider increasing the value to match common proxy/browser defaults.' }
+     );
+   }
   } else {
-    this.keepAliveTimeout = 5_000; // 5 seconds;
+    this.keepAliveTimeout = 60_000; // 60 seconds
+    process.emitWarning(
+     'The default http.Server.keepAliveTimeout has changed from 5000ms (5s) to 60000ms (60s) in Node.js v24.0.0. ' +
+     'This change aligns Node.js with common proxy and browser expectations and prevents subtle long-lived connection failures. ' +
+     'If your application relies on the previous default, set it explicitly. See: https://github.com/nodejs/node/issues/59193',
+     { code: 'KEEPALIVETIMEOUT_DEFAULT_CHANGED', detail: 'Check your infrastructure and client expectations.' }
+    );
   }
 
   const connectionsCheckingInterval = options.connectionsCheckingInterval;