Graph showing some url Min=0

Gatling (Open-Source)
1

I have run 15 hours gatling on my scenarios. And notices that some of the request has “0ms” in the Min column. Is that possible?

2

Do you see those 0ms in the generated reports, or in the simulation.log file?
Duration measurement is a tricky thing… Even with System.nanoTime, one can have cores desynchronization (meaning start was measured one one core, end on another one). Things are worse on Windows than on X platforms.
Then, we have an accuracy config param (in gatling.conf) for rounding up times during report generation and lessen memory consumption. That you can tune.

Cheers,

Stéphane

3

One last possibility is that the request failed because the server immediately refused to connect.

4

Yeah, I am seeing a lot of KO request that has the same start and end time stamp:

This is one line that in the simulation log, seems like the 2 timestamp are the same:

REQUEST ViewDocumentExt Scence 1314 /docs/DOC-1031 1371491435702 1371491435702 1371491435930 1371491435995 KO status().is(200) didn’t match: expected 200 but found 403

Can you tell me what each column means?

BTW, there is another line in the similation log like:
SCENARIO ProfilePlaces Scence 1414 1371491433801 1371491435782

What are the columns means in this line?

Thx

5

Yeah, I am seeing a lot of KO request that has the same start and end time
stamp:

This is one line that in the simulation log, seems like the 2 timestamp
are the same:

REQUEST ViewDocumentExt Scence 1314 /docs/DOC-1031
1371491435702 1371491435702 1371491435930 1371491435995 KO
status().is(200) didn't match: expected 200 but found 403

Can you tell me what each column means?

The timestamps are described here:

So in this case, have the 2 first timestamps equal looks OK to me (and
wouldn't cause a 0ms response time).

BTW, there is another line in the similation log like:
SCENARIO ProfilePlaces Scence 1414 1371491433801 1371491435782

What are the columns means in this line?

record type / Scenario name, user id, start, end

Cheers,

Stéphane

6

I am seeing this in the generated reports. I didn’t go to simulation log to do the math. (or you mean other way?) I use the different accuracy, seems having similar result.

Is there any suggestion on how to alleviate this?

7

Default accuracy is 10ms. Did you try 1 ms?
Did you get those 0ms only with KO requests, or also with OK ones?
What’s your OS?