Enabling node.js source maps increases neo4j-driver total execution time by 70x+ on my machine

[ztratar]

When i run neo4j in my node.js app, if --enable-source-maps is enabled, the average query time moves from 10ms to over a second.

Some more details:

We have a node.js backend application. When I run in using yarn dev
(e.g. DEBUG=backend* node --enable-source-maps build.js --start --watch")

All queries and operations take about a second minimum.

When I then build that javascript app "rm -rf dist && NODE_ENV=development node build.js
And then run dist/index.js.. boom, 1 second turns to 7ms.

For building I am using esbuild.
When I run a hybrid node build.js --start --watch manually... even though I'm watching as in normal dev mode, the query time remains performant.

I've been able to narrow this down to purely source maps. I don't know why source maps should affect neo4j query performance, but I would like to have them enabled and still be able to run development with speedy queries.

[bigmontz]

Thanks for the report @ztratar, which driver and node versions are you using?

[bigmontz]

I don't have issue with my simple esbuild setup here:

package.json

{
  "name": "gh1168",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "devDependencies": {
    "esbuild": "^0.19.11"
  },
  "dependencies": {
    "neo4j-driver": "^5.16.0"
  },
  "scripts": {
    "build": "esbuild index.js --bundle --platform=node --sourcemap --outfile=bin/out.js"
  }
}

index.js

const neo4j = require('neo4j-driver')


const driver = neo4j.driver('neo4j://localhost:7687', neo4j.auth.basic('neo4j', 'password'))


performance.measure('Start to Now');
performance.mark('Before Query');

driver.executeQuery('RETURN 1', {}, {
    database: 'neo4j'
}).then(() => {
    performance.mark('After Query')
    
    const measure = performance.measure('Query Time', 'Before Query', 'After Query');

    console.log('Query took', measure.duration)
}).finally(() => driver.close())

Command line:

yarn build && node bin/out.js

[ztratar]

Hello! This was happening on 16.19.

We've now upgraded to node 20 LTS, and, oddly enough, it appears the query times have all improved to normal with that change.

[bigmontz]

I've tried my sample with project with node v16.19.0 and I can't reproduce the problem.
I can't figure out what's happening. Can you reproduce the problem with the setup I shared?

Thanks