OrienDb.RequestError: Found unknown session x

Question

I'm using OrientJs to communicate with OrientDB through node.js. I've implemented an API to insert a new User into the db, after checking whether he does exist.

var dbServer = OrientDB({
    host: 'localhost',
    port: 2424,
    username: 'root',
    password: 'password'
});

// Connect to db 'test'
var db = dbServer.use({
    name: 'mydbtest',
    username: 'root',
    password: 'my_root_password'
})

// Set the server...

app.post('/insertUser/', function (req, res) {
    let username = req.body.username
    let password = req.body.password

    //Checks on username and password ...

    let fetcher = require('../fetcher/fetcher')
    fetcher.userExists(db, username, password).then(function (exists) {
        console.log(exists) //exists = true/false
        if (!exists) {
            db.open().then(
                db.let('user', function (user) {
                    user.create('vertex', 'User')
                        .set({
                            username: username,
                            password: password
                        })
                }).commit().return('$user').one().then(function (result) {
                    db.close()
                    if (!result.undefined) { res.status(200).send(true) }
                    else { res.status(200).send(false) }
                }).catch(function (e) {  // The error is caught here
                    db.close()
                    console.error(e);  
                    res.status(500).send({ message: 'Unable to save new user1' })
                })
            ).catch(function (e) {
                db.close()
                res.status(500).send({ message: 'Unable to save new user' })
            })
        }

        else res.status(200).send(false)
    })
})

Where fetcher.userExists(db, username, password) is a function that return true if the user does exist, false otherwise. When calling thi api from Postman, i receive this error message:

{ OrientDB.RequestError
at child.Operation.parseError (C:\Users\sdp\node_modules\orientjs\lib\transport\binary\protocol33\operation.js:896:13)
at child.Operation.consume (C:\Users\sdp\node_modules\orientjs\lib\transport\binary\protocol33\operation.js:487:35)
at Connection.process (C:\Users\sdp\node_modules\orientjs\lib\transport\binary\connection.js:410:17)
at Connection.handleSocketData (C:\Users\sdp\node_modules\orientjs\lib\transport\binary\connection.js:301:20)
at emitOne (events.js:115:13)
at Socket.emit (events.js:210:7)
at addChunk (_stream_readable.js:252:12)
at readableAddChunk (_stream_readable.js:239:11)
at Socket.Readable.push (_stream_readable.js:197:10)
at TCP.onread (net.js:588:20)
name: 'OrientDB.RequestError',
message: 'Found unknown session 13',
data: {},
previous: [],
id: 1,
type: 'com.orientechnologies.common.io.OIOException',
hasMore: 0 }

The message is Found unknown session 13, but it increases the number by 2 each time I call the service.

If I put the code in the if(!exists){}statement out of the then block of fetcher.userExists(db, username, password).then(function (exists) {.. it works fine, but doing so I can check if the user exists. I can figure out what's the problem. Can someone help me? Thanks.

Note: I'm using OrientDB Community 2.2.24

Answer 1

The issue was the db connection in the fetcher.userExists(db, username, password), In that method I made a query to find if user exists (in a similar way I do in the code I posted). So, I opened the connection with db.open() and then, before returning the result, I closed it simply performing db.close(). I didn't close it properly. The code after db.close() should be in the then block, like this:

//...
if (!exists) {
    db.open().then(
        db.let('user', function (user) {
            user.create('vertex', 'User')
                .set({
                    username: username,
                    password: password
                 })
        }).commit().one().then(function (result) {
            db.close().then(function(){     // <--- ADD then BLOCK HERE
                if (!result.undefined) { res.status(200).send(true) }
                else { res.status(200).send(false) }
            })
        })
    })
}

So, after opening the connection in fetcher.userExists(db, username, password) it was like I tried to open a new connection and execute query before the old one was closed. Putting the code in then() after db.close() avoid this.