[BUG.v5.2.1] ClientSession cannot be serialized to BSON - Sessions #6663
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docs
This issue is due to a mistake or omission in the mongoosejs.com documentation
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I haven't used sessions at all yet, so I'm really not sure if this should work or not. I was able to create a complete repro script that demonstrates the outcome based on some assumptions about @GregoryNEUT's code sample. 6663.js#!/usr/bin/env node --no-deprecation
'use strict';
const { ATLASSRV } = require('/Users/lineus/.env');
const mongoose = require('mongoose');
mongoose.connect(ATLASSRV.replace(/test/, 'gh-6663'));
const conn = mongoose.connection;
const Schema = mongoose.Schema;
const schemaA = new Schema({
name: String
});
const schemaB = new Schema({
name: String
});
const A = mongoose.model('A', schemaA);
const B = mongoose.model('B', schemaB);
const a = new A({ name: 'Andrew' });
const b = new B({ name: 'Billy' });
async function run() {
await conn.dropDatabase();
await a.save();
await b.save();
const session = await A.startSession();
const foundA = await A.findOne({}, { session });
await B.findOneAndUpdate({}, { name: foundA.name }, { session });
await session.commitTransaction();
session.endSession();
let newB = await B.findOne({});
console.log(`hello from ${newB.name}`);
return conn.close();
}
run().catch(console.error);Output:something about creating the session on the first model, and passing it to a query on the second model feels wrong |
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This is a common gotcha that we should add docs for, but your issue is that the 2nd arg to |
vkarpov15
added
the
docs
|
@vkarpov15 LOL 🤕 I can't believe I missed that. I had to make a couple of adjustments to my example that were wrong beyond the missing projection. In case it might help someone in the future here is the working code: 6663.js#!/usr/bin/env node --no-deprecation
'use strict';
const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017,localhost:27018,localhost:27019/gh-6663?replicaSet=rs');
const conn = mongoose.connection;
const Schema = mongoose.Schema;
const schemaA = new Schema({
name: String
});
const schemaB = new Schema({
name: String
});
const A = mongoose.model('A', schemaA);
const B = mongoose.model('B', schemaB);
const a = new A({ name: 'Andrew' });
const b = new B({ name: 'Billy' });
async function run() {
await conn.dropDatabase();
await a.save();
await b.save();
const session = await A.startSession();
await session.startTransaction();
const foundA = await A.findOne({}, {}, { session });
await B.findOneAndUpdate({}, { name: foundA.name }, { session });
await session.commitTransaction();
session.endSession();
let newB = await B.findOne({});
console.log(`hello from ${newB.name}`);
return conn.close();
}
run().catch(console.error);Output: |
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It is a real bug in debug environment. mongoose.set('debug', true); |
const {MongoClient} = require('mongodb');
const uri = 'mongodb://localhost:27017,localhost:27018,localhost:27019/test-mongodb';
MongoClient.connect(uri, {useNewUrlParser: true, replicaSet: 'rs'}).then(async (client) => {
// console.log(client);
const db = client.db();
await db.dropDatabase();
await db.collection('Account').insertMany([
{name: 'A', balance: 5},
{name: 'B', balance: 10}
]);
await transfer('A', 'B', 4); // Success
try {
await transfer('A', 'B', 6);
} catch (error) {
console.log(error);
}
// The actual transfer logic
async function transfer(from, to, amount) {
const session = client.startSession();
session.startTransaction();
try {
const opts = {session, returnOriginal: false};
const B = await db.collection('Account').findOneAndUpdate({name: to}, {$inc: {balance: amount}}, opts).then(res => res.value);
const A = await db.collection('Account').findOneAndUpdate({name: from}, {$inc: {balance: -amount}}, opts).then(res => res.value);
if (A.balance < 0) {
// If A would have negative balance, fail and abort the transaction
// `session.abortTransaction()` will undo the above `findOneAndUpdate()`
throw new Error('Insufficient funds: ' + (A.balance + amount));
}
await session.commitTransaction();
session.endSession();
return {from: A, to: B};
} catch (error) {
// If an error occurred, abort the whole transaction and
// undo any changes that might have happened
await session.abortTransaction();
session.endSession();
throw error; // Rethrow so calling function sees error
}
}
}).catch(console.log);
@vkarpov15 your example worked |
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Hello; trying to use simple transaction case as described in the documentation; I'm getting an error
My code look like :
Versions I use :
Thanks
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