feat(NODE-7020): remove ping on connect

src/sdam/topology.ts

@@ -46,7 +46,6 @@ import {
   makeStateMachine,
   noop,
   now,
-  ns,
   promiseWithResolvers,
   shuffle
 } from '../utils';
@@ -469,9 +468,11 @@ export class Topology extends TypedEventEmitter<TopologyEvents> {
         readPreferenceServerSelector(readPreference),
         selectServerOptions
       );
+
       const skipPingOnConnect = this.s.options.__skipPingOnConnect === true;
       if (!skipPingOnConnect && this.s.credentials) {
-        await server.command(ns('admin.$cmd'), { ping: 1 }, { timeoutContext });
+        const connection = await server.pool.checkOut({ timeoutContext: timeoutContext });
+        server.pool.checkIn(connection);
         stateTransition(this, STATE_CONNECTED);
         this.emit(Topology.OPEN, this);
         this.emit(Topology.CONNECT, this);

test/integration/node-specific/auto_connect.test.ts

@@ -842,32 +842,6 @@ describe('When executing an operation for the first time', () => {
       });
     });
 
-    describe(
-      'when the server requires auth and ping is delayed',
-      { requires: { auth: 'enabled', mongodb: '>=4.4' } },
-      function () {
-        beforeEach(async function () {
-          // set failpoint to delay ping
-          // create new util client to avoid affecting the test client
-          const utilClient = this.configuration.newClient();
-          await utilClient.db('admin').command({
-            configureFailPoint: 'failCommand',
-            mode: { times: 1 },
-            data: { failCommands: ['ping'], blockConnection: true, blockTimeMS: 1000 }
-          } as FailPoint);
-          await utilClient.close();
-        });
-
-        it('timeoutMS from the client is not used for the internal `ping`', async function () {
-          const start = performance.now();
-          const returnedClient = await client.connect();
-          const end = performance.now();
-          expect(returnedClient).to.equal(client);
-          expect(end - start).to.be.within(1000, 1500); // timeoutMS is 1000, did not apply.
-        });
-      }
-    );
-
     describe(
       'when server selection takes longer than the timeout',
       { requires: { auth: 'enabled', mongodb: '>=4.4' } },

test/integration/node-specific/mongo_client.test.ts

@@ -18,7 +18,7 @@ import {
   ServerDescription,
   Topology
 } from '../../mongodb';
-import { clearFailPoint, configureFailPoint, runLater } from '../../tools/utils';
+import { clearFailPoint, configureFailPoint } from '../../tools/utils';
 import { setupDatabase } from '../shared';
 
 describe('class MongoClient', function () {
@@ -588,30 +588,27 @@ describe('class MongoClient', function () {
     });
 
     it(
-      'creates topology and send ping when auth is enabled',
+      'creates topology and checks out connection when auth is enabled',
       { requires: { auth: 'enabled' } },
       async function () {
-        const commandToBeStarted = once(client, 'commandStarted');
+        const checkoutStarted = once(client, 'connectionCheckOutStarted');
         await client.connect();
-        const [pingOnConnect] = await commandToBeStarted;
-        expect(pingOnConnect).to.have.property('commandName', 'ping');
+        const checkout = await checkoutStarted;
+        expect(checkout).to.exist;
         expect(client).to.have.property('topology').that.is.instanceOf(Topology);
       }
     );
 
     it(
-      'does not send ping when authentication is disabled',
+      'does not checkout connection when authentication is disabled',
       { requires: { auth: 'disabled' } },
       async function () {
-        const commandToBeStarted = once(client, 'commandStarted');
+        const checkoutStartedEvents = [];
+        client.on('connectionCheckOutStarted', event => {
+          checkoutStartedEvents.push(event);
+        });
         await client.connect();
-        const delayedFind = runLater(async () => {
-          await client.db().collection('test').findOne();
-        }, 300);
-        const [findOneOperation] = await commandToBeStarted;
-        // Proves that the first command started event that is emitted is a find and not a ping
-        expect(findOneOperation).to.have.property('commandName', 'find');
-        await delayedFind;
+        expect(checkoutStartedEvents).to.be.empty;
         expect(client).to.have.property('topology').that.is.instanceOf(Topology);
       }
     );
@@ -620,15 +617,15 @@ describe('class MongoClient', function () {
       'permits operations to be run after connect is called',
       { requires: { auth: 'enabled' } },
       async function () {
-        const pingCommandToBeStarted = once(client, 'commandStarted');
+        const checkoutStarted = once(client, 'connectionCheckOutStarted');
         await client.connect();
-        const [pingOnConnect] = await pingCommandToBeStarted;
+        const checkout = await checkoutStarted;
+        expect(checkout).to.exist;
 
         const findCommandToBeStarted = once(client, 'commandStarted');
         await client.db('test').collection('test').findOne();
         const [findCommandStarted] = await findCommandToBeStarted;
 
-        expect(pingOnConnect).to.have.property('commandName', 'ping');
         expect(findCommandStarted).to.have.property('commandName', 'find');
         expect(client).to.have.property('topology').that.is.instanceOf(Topology);
       }
@@ -1186,24 +1183,28 @@ describe('class MongoClient', function () {
 
       const tests = [
         // only skipInitialPing=true will have no events upon connect
-        { description: 'should skip ping command when set to true', value: true, expectEvents: 0 },
         {
-          description: 'should not skip ping command when set to false',
+          description: 'should skip connection checkout when set to true',
+          value: true,
+          expectEvents: 0
+        },
+        {
+          description: 'should not skip connection checkout when set to false',
           value: false,
           expectEvents: 1
         },
         {
-          description: 'should not skip ping command when unset',
+          description: 'should not skip connection checkout command when unset',
           value: undefined,
           expectEvents: 1
         }
       ];
       for (const { description, value, expectEvents } of tests) {
         it(description, async function () {
           const options = value === undefined ? {} : { __skipPingOnConnect: value };
-          const client = this.configuration.newClient({}, { ...options, monitorCommands: true });
+          const client = this.configuration.newClient({}, { ...options });
           const events = [];
-          client.on('commandStarted', event => events.push(event));
+          client.on('connectionCheckOutStarted', event => events.push(event));
 
           try {
             await client.connect();
@@ -1212,11 +1213,6 @@ describe('class MongoClient', function () {
           }
 
           expect(events).to.have.lengthOf(expectEvents);
-          if (expectEvents > 1) {
-            for (const event of events) {
-              expect(event).to.have.property('commandName', 'ping');
-            }
-          }
         });
       }
     });