Unable to connect to mysql after upgrading to 2.3.3

[rrosenblum]

After upgrading from version 2.2.0 to 2.3.3, I am unable to connect to mysql. I believe this is related to #98. There isn't much of an actual error being produced that I can see. The lambda just winds up timing out without ever actually connecting to mysql. I have tried increasing the timeout. I think this might be related to #98.

I have tried 2 different ways to capture mysql.

const AWSXRay = require('aws-xray-sdk-core');    
const captureMySQL = require('aws-xray-sdk-mysql');    
const mysql = captureMySQL(require('mysql'));    
                                         
const pool = mysql.createPool({    
  host: process.env.DB_PRIMARY_ENDPOINT,    
  database: process.env.DB_NAME,    
  port: process.env.DB_PORT,    
  user: process.env.DB_USERNAME,    
  password: process.env.DB_PASSWORD    
});

module.exports.handler = async (event) => {
  pool.query
}

const mysql = require('aws-xray-sdk').captureMySQL(require('mysql'));    
    
const pool = mysql.createPool({    
  host: process.env.DB_PRIMARY_ENDPOINT,    
  database: process.env.DB_NAME,    
  port: process.env.DB_PORT,    
  user: process.env.DB_USERNAME,    
  password: process.env.DB_PASSWORD    
});

module.exports.handler = async (event) => {
  pool.query
}

[awssandra]

Hi rrosenblum,

Sorry for the issues. We'll do some testing on our end to see what the issue is. I think it's a fair call that the mysql2 changes may have broken the mysql patch functionality.

[M-TGH]

Hey,

Thanks for the report. My apologies for any inconveniences. I didn't have too much time so far to look into it, but I was able to reproduce it. For now it should be alright to (temporarily) remove the parts that patch a Pool it's getConnection function.

So far it looked like it's somewhere down that line that something was hitting a snag, maybe because the MySQL package internally uses getConnection on the Pool when using Pool.query. Unfortunately I couldn't yet figure out the full problem, but I'll try looking into it more as soon as I have the time.

Suppose it might be interesting to see if this can be replicated with a test which stubs/simulates a Pool's query function.

Let me know if I can be of any more help.

[M-TGH]

After looking into it further, Pool.query creates a Query instance and a connection and then calls the connection.query function with only the Query instance as argument. This falls into this case, from further up in query: https://github.com/mysqljs/mysql/blob/99d6f78ba00f926de162dbef42865029b6e8ec39/lib/Connection.js#L26

It's currently going into this if statement:

aws-xray-sdk-node/packages/mysql/lib/mysql_p.js

Line 142 in ad817e5

if (argsObj[0] instanceof Object) {

Which then splits up the Query instance that was passed through and currently makes it so that a new one is created by calling Connection.query with its sql and values, thereby losing the original Query instances EventEmitter.

[yvele]

Same problem with aws-xray-sdk-mysql version >=2.3.0

Temporary workaround, downgrade aws-xray-sdk-mysql:

"dependencies": {
    "aws-xray-sdk-core": "~2.3.3",
    "aws-xray-sdk-mysql": "2.2.0"
}

[willarmiros]

Closing since it was fixed in PR.