Hi there

I hope someone can help with this issue which is driving me crazy.

While testing some newly implemented caching on an export endpoint here (locally) we ran into a weird problem with the k6 tests to verify the new and hopefully faster response times.

After some troubleshooting we have simplified the test as much as possible, and are now sending one single http get request (receiving about 23 MB of JSON). We have set discardResponseBodies to true. The script is about as minimal as is possible.

It seems like k6 adds about 20 seconds overhead on the response times. Using other tools (we have tried Postman, Insomnia, ThunderClient, curl and now finally Gatling) we were able to measure the response times to 300-500ms with a populated cache, while k6 consequently shows ~20 seconds.

Requests to other endpoints in the same API are showing fast response times, so we figure it must have something to do with k6 and the 20+ megabyte response, somehow.

Any idea what could be causing this?

edit;

here is an example of a report showing a http_req_receiving time of 19.4s:

```
data_received..................: 23 MB 1.2 MB/s
data_sent......................: 109 kB 5.5 kB/s
http_req_blocked...............: avg=103.83ms min=103.83ms med=103.83ms max=103.83ms p(90)=103.83ms p(95)=103.83ms
http_req_connecting............: avg=0s min=0s med=0s max=0s p(90)=0s p(95)=0s
http_req_duration..............: avg=19.51s min=19.51s med=19.51s max=19.51s p(90)=19.51s p(95)=19.51s
{ expected_response:true }...: avg=19.51s min=19.51s med=19.51s max=19.51s p(90)=19.51s p(95)=19.51s
http_req_failed................: 0.00% ✓ 0 ✗ 1
http_req_receiving.............: avg=19.4s min=19.4s med=19.4s max=19.4s p(90)=19.4s p(95)=19.4s
http_req_sending...............: avg=0s min=0s med=0s max=0s p(90)=0s p(95)=0s
http_req_tls_handshaking.......: avg=102.1ms min=102.1ms med=102.1ms max=102.1ms p(90)=102.1ms p(95)=102.1ms
http_req_waiting...............: avg=111.22ms min=111.22ms med=111.22ms max=111.22ms p(90)=111.22ms p(95)=111.22ms
http_reqs......................: 1 0.050977/s
iteration_duration.............: avg=19.61s min=19.61s med=19.61s max=19.61s p(90)=19.61s p(95)=19.61s
iterations.....................: 1 0.050977/s
vus............................: 1 min=1 max=1
vus_max........................: 1 min=1 max=1
```