fix: remove changes outside deprecations

Author: durran

src/cmap/connect.ts

@@ -329,13 +329,14 @@ const SOCKET_ERROR_EVENTS = new Set(SOCKET_ERROR_EVENT_LIST);
 function makeConnection(options: MakeConnectionOptions, _callback: Callback<Stream>) {
   const useTLS = options.tls ?? false;
   const keepAlive = options.keepAlive ?? true;
+  const socketTimeoutMS = options.socketTimeoutMS ?? Reflect.get(options, 'socketTimeout') ?? 0;
   const noDelay = options.noDelay ?? true;
   const connectTimeoutMS = options.connectTimeoutMS ?? 30000;
   const rejectUnauthorized = options.rejectUnauthorized ?? true;
-  // Default to delay to 300 seconds. Node automatically then sets TCP_KEEPINTVL to 1 second
-  // which is acceptable to the recommendation of 10 seconds and also cannot be configured.
-  // TCP_KEEPCNT is also set to 10 in Node and cannot be configured. (Recommendation is 9)
-  const keepAliveInitialDelay = options.keepAliveInitialDelay;
+  const keepAliveInitialDelay =
+    ((options.keepAliveInitialDelay ?? 120000) > socketTimeoutMS
+      ? Math.round(socketTimeoutMS / 2)
+      : options.keepAliveInitialDelay) ?? 120000;
   const existingSocket = options.existingSocket;
 
   let socket: Stream;

src/connection_string.ts

@@ -870,7 +870,7 @@ export const OPTIONS = {
     deprecated: 'Will not be able to turn off in the future.'
   },
   keepAliveInitialDelay: {
-    default: 300000,
+    default: 120000,
     type: 'uint',
     deprecated: 'Will not be configurable in the future.'
   },

test/unit/mongo_client.test.js

@@ -610,7 +610,7 @@ describe('MongoOptions', function () {
       ['forceserverobjectid', false],
       ['heartbeatfrequencyms', 10000],
       ['keepalive', true],
-      ['keepaliveinitialdelay', 300000],
+      ['keepaliveinitialdelay', 120000],
       ['localthresholdms', 15],
       ['maxidletimems', 0],
       ['maxpoolsize', 100],