Profiling Workers - same timstamp for start and end times

[tomas.cerkasas]

Hi,

am trying to achieve a very basic profiler by measuring difference in miliseconds in several different code execution points.

    start_time = Date.now()
<...>
     end_time = Date.now()
    diff_time = end_time - start_time

The values these variables get assigned are as follows:
Start time: 1569593739079 End time: 1569593739079 Diff time: 0 .

I would expect at least the minimall difference - what am I missing here?

Thanks!

[adaptive]

I personally return this on the header when debugging.

Best way to get origin response time in worker?

I have this code(simplified) which seems to work, but some requests end up so fast that I am not sure if they actually that fast or the code is wrong: requestStartTime = Date.now(); const response = await fetch(event.request); requestEndTime = Date.now(); originTime = requestEndTime - requestStartTime; is is possible for the requestEndTime line to run before response is fetched?

[thomas4]

It was mentioned in a previous discussion by Cloudflare that…
" Date.now() only advances when I/O is performed, however, and is intentionally coarse."

Which means that you can’t measure how long a worker takes to do some work, but you can measure how long requests using fetch take to complete. If i remember correctly, they also make exact timing harder to avoid timing attacks.