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  1. Node.js Driver
  2. NODE-679

4000 connections from MongoClient, caused by reconnects

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • 2.1.10
    • Affects Version/s: 2.1.8
    • Component/s: MongoDB 3.2
    • Labels:
    • Environment:
      using nodejs 5.7.1

      We're seeing lots of connection from a machine which is running 2.1.8. We're connecting to a replicaSet.

      MongoClient
          .connect(mongoUrl, {promiseLibrary: Promise})
          .then(adminDb => {
            adminDb.on('reconnect', () => console.log('reconnect', new Error().stack))
          })
      

      When the reconnect logs appear, we see 4 connections being made within a couple of milliseconds.

      The stacktrace we're printing is not always the same:

          at null.<anonymous> (/opt/myproject/src/mongodb/index.js:35:49)
          at emitTwo (events.js:100:13)
          at emit (events.js:185:7)
          at listener (/opt/myproject/node_modules/mongodb/lib/db.js:1729:14)
          at emitNone (events.js:80:13)
          at emit (events.js:179:7)
          at null.<anonymous> (/opt/myproject/node_modules/mongodb/lib/replset.js:200:10)
          at emitOne (events.js:90:13)
          at emit (events.js:182:7)
          at State.update (/opt/myproject/node_modules/mongodb-core/lib/topologies/replset_state.js:471:20)
          at /opt/myproject/node_modules/mongodb-core/lib/topologies/replset.js:1146:27
          at commandCallback (/opt/myproject/node_modules/mongodb-core/lib/topologies/server.js:945:9)
          at Callbacks.emit (/opt/myproject/node_modules/mongodb-core/lib/topologies/server.js:116:3)
          at null.messageHandler (/opt/myproject/node_modules/mongodb-core/lib/topologies/server.js:288:23)
          at Socket.<anonymous> (/opt/myproject/node_modules/mongodb-core/lib/connection/connection.js:320:20)
          at emitOne (events.js:90:13)
          at Socket.emit (events.js:182:7)
      

      or

          at null.<anonymous> (/opt/myproject/src/mongodb/index.js:35:49)
          at emitTwo (events.js:100:13)
          at emit (events.js:185:7)
          at listener (/opt/myproject/node_modules/mongodb/lib/db.js:1729:14)
          at emitNone (events.js:80:13)
          at emit (events.js:179:7)
          at null.<anonymous> (/opt/myproject/node_modules/mongodb/lib/replset.js:200:10)
          at emitOne (events.js:90:13)
          at emit (events.js:182:7)
          at State.update (/opt/myproject/node_modules/mongodb-core/lib/topologies/replset_state.js:471:20)
          at processNewServer (/opt/myproject/node_modules/mongodb-core/lib/topologies/replset.js:1311:27)
          at null.<anonymous> (/opt/myproject/node_modules/mongodb-core/lib/topologies/replset.js:1364:46)
          at g (events.js:273:16)
          at emitOne (events.js:90:13)
          at emit (events.js:182:7)
          at /opt/myproject/node_modules/mongodb-core/lib/topologies/server.js:497:23
      

      When I revert to 2.1.4, this is reconnecting doesn't happen. The mongodb primary's connections are stable again.

            Assignee:
            christkv Christian Amor Kvalheim
            Reporter:
            jaap@q42.nl Jaap Taal
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              Created:
              Updated:
              Resolved: