Situation:

I have a Node.js api that is called many times a second on a website. I am using console.time('RESPONSE TIME') and console.timeEnd('RESPONSE TIME') to measure how long the api is taking to respond to the client on to each request. Inside of the api, I am using a Promise.all() to aggregate responses from 4 different api's and then return a final response based on what the 4 apis returned.

Issue:

Everything works as expected except for an occasional warning logged Warning: No such label 'RESPONSE TIME' for console.timeEnd(). Why is this and how do I properly avoid this?

I speculate that it's because Node is asynchronous and while one request may still be waiting for it's 4 api's to respond, another request will have finished and hit the console.timeEnd() ending both timers since they share the same name. But I can't find an answer anywhere.

Situation:

I have a Node.js api that is called many times a second on a website. I am using console.time('RESPONSE TIME') and console.timeEnd('RESPONSE TIME') to measure how long the api is taking to respond to the client on to each request. Inside of the api, I am using a Promise.all() to aggregate responses from 4 different api's and then return a final response based on what the 4 apis returned.

Issue:

Everything works as expected except for an occasional warning logged Warning: No such label 'RESPONSE TIME' for console.timeEnd(). Why is this and how do I properly avoid this?

I speculate that it's because Node is asynchronous and while one request may still be waiting for it's 4 api's to respond, another request will have finished and hit the console.timeEnd() ending both timers since they share the same name. But I can't find an answer anywhere.

• javascript
• node.js
• express
• asynchronous

• can't you just log Date.now() - msStart instead of using the console timing feature? that way, you don't have to worry about order of operations or rush conditions. – dandavis Commented May 21, 2019 at 19:09
• @dandavis I thought about that. It's a solution but ideally I'd like to use console.time() since it's cleaner and that's what it's made for. Every ms counts so I'd rather avoid using things like the Date object – Ryan Walker Commented May 21, 2019 at 21:04
• Even I am thinking about the explanation you are giving but would like to know if that's the exact reason? – Saras Arya Commented Jan 6, 2020 at 15:14
• @SarasArya In regards to the original question? I still haven't found the answer. – Ryan Walker Commented Jan 6, 2020 at 21:40

1 Answer 1

Your speculation is correct, you should have a unique label name for every api call. Assuming every request has a unique identifier stored in req.id you can use the following:

console.time(`RESPONSE TIME request ${req.id}`)
// await api call
console.timeEnd(`RESPONSE TIME request ${req.id}`)