Node.js MongoError:写入冲突

模式定义 用户集合：（optimisticConcurrency:true）

预订收藏（没有对该收藏施加优化一致性y）

所有对后端的api调用都有一个authenticate（）中间件要交叉，该中间件在验证auth头中的令牌后通过查询用户进行身份验证。然后检索用户对象并最终更新以下属性

pingdat→ 当前日期

{
  _id: [Object Id],
  pingedAt: [Date],
  currentBal: [Int32],
  { ...otherUserAttibutes }
}

导致问题的场景：

12:01:01:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:

12:01:01:200ms用户进行/预订-接听电话，12:01:01:250ms在身份验证期间更新用户的pingedAt

到12:01:01:300ms，通过会话检索到的预订更改为取消

在同一个取消预订电话中，我们将钱添加到用户的钱包中。假设预订费是300/-。在12:01:01:350ms，我们将用户对象与更新的余额一起保存

WriteConflict引发错误，因为同一用户对象已在12:01:01发生更改：250ms

错误日志

MongoError: WriteConflict
  at MessageStream.messageHandler (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/connection.js:268:20)
  at MessageStream.emit (events.js:315:20)
  at MessageStream.EventEmitter.emit (domain.js:483:12)
  at processIncomingData (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/message_stream.js:144:12)
  MessageStream._write (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/message_stream.js:42:5)
  at doWrite (_stream_writable.js:403:12)
  writeOrBuffer (_stream_writable.js:387:5)
  at MessageStream.Writable.write (_stream_writable.js:318:11)
  at TLSSocket.ondata (_stream_readable.js:716:22)
  at TLSSocket.emit (events.js:315:20)
  at TLSSocket.EventEmitter.emit (domain.js:483:12)
  at addChunk (_stream_readable.js:295:12)
  at readableAddChunk (_stream_readable.js:271:9)
  at TLSSocket.Readable.push (_stream_readable.js:212:10)
  at TLSWrap.onStreamRead (internal/stream_base_commons.js:186:23)
  at TLSWrap.callbackTrampoline (internal/async_hooks.js:120:14)}

    const session = await mongoose.startSession();
    session.startTransaction();
    const booking = await this.bookingsRepository.getBookingWithSession({ _id: bookingId }, session)

    user.pingedAt = new Date();
    await user.save();

    booking.status = 3
    await booking.save({ session })

    booking.user.currentBal = booking.user.currentBal + 300
    await booking.user.save({ session });

MongoError: WriteConflict
  at MessageStream.messageHandler (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/connection.js:268:20)
  at MessageStream.emit (events.js:315:20)
  at MessageStream.EventEmitter.emit (domain.js:483:12)
  at processIncomingData (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/message_stream.js:144:12)
  MessageStream._write (/home/ubuntu/api.backend.js/node_modules/mongodb/lib/cmap/message_stream.js:42:5)
  at doWrite (_stream_writable.js:403:12)
  writeOrBuffer (_stream_writable.js:387:5)
  at MessageStream.Writable.write (_stream_writable.js:318:11)
  at TLSSocket.ondata (_stream_readable.js:716:22)
  at TLSSocket.emit (events.js:315:20)
  at TLSSocket.EventEmitter.emit (domain.js:483:12)
  at addChunk (_stream_readable.js:295:12)
  at readableAddChunk (_stream_readable.js:271:9)
  at TLSSocket.Readable.push (_stream_readable.js:212:10)
  at TLSWrap.onStreamRead (internal/stream_base_commons.js:186:23)
  at TLSWrap.callbackTrampoline (internal/async_hooks.js:120:14)}