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Re: Performance issue with libcurl 7.73

From: Ray Satiro via curl-library <curl-library_at_cool.haxx.se>
Date: Fri, 30 Oct 2020 04:02:06 -0400

On 10/29/2020 7:57 PM, Jeffrey McKay via curl-library wrote:
> Recently we did have some problem with logging in to some servers, and
> I determined that the issue
> could be fixed by updating to libcurl 7.71 (not sure why). However I
> ran into some other problem
> with this version, where for some reason after several thousand
> messages, libcurl seemed to be
> returning null data in response to a GET. However I am*not* asking
> about that problem in this
> message.
>
> The above problem went away when I switched to libcurl 7.73. However,
> this version has its own
> problem, a serious performance issue, where large chunks of data seem
> to be taking 1 second to
> upload, vs a fraction of a second seen with the previous version.
>
> Take a look at the attached two log files, slow_upload.txt and
> fast_upload.txt. These are
> logs of the debug function after I do a POST. In the slow version,
> each 64k chunk of data
> is taking approximately 1 second. In the fast version, each chunk is a
> fraction of a second or
> not even measurable. These results are consistent when doing multiple
> tests at different times
> of the day. I don't think it is related to EWS server variability.
>
> Keep in mind that the exact same main program binary executable code
> is running in each test, only
> the libcurl.dll has been changed.
>
> Any idea what could be causing this? I've also included some of my
> code that performs the POST
> operation (cleaned up of a lot of extraneous stuff). Hopefully there
> is some curl option that
> I can set or change that fixes this.


I was able to reproduce this and have filed a bug report [1]. If you
can, please take any further comments about this issue to that report
instead of the mailing list. Thanks

[1]: https://github.com/curl/curl/issues/6146

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Received on 2020-10-30