PutObject extremely slow when using web debugging proxy

[TommyN]

I'm replacing an old (non AWS) S3 library with AWSSDK.S3
When running Fiddler (Web debugging proxy) on my local windows box I see a massive slowdown when uploading files using PutObjectAsync.

With Fiddler running:

Upload took: 1582 ms
Upload took: 1187 ms
Upload took: 1104 ms
Upload took: 1107 ms
Upload took: 1107 ms
Upload took: 1124 ms

Without:

Upload took: 809 ms
Upload took: 162 ms
Upload took: 168 ms
Upload took: 170 ms
Upload took: 150 ms
Upload took: 164 ms
Upload took: 129 ms

The library I'm replacing doesn't take any noticeable performance hit when running Fiddler.
Any idea what the problem might be? Should I report this as a bug?

<PackageReference Include="AWSSDK.S3" Version="3.7.9.21" />

[ashishdhingra]

@TommyN I'm unsure what the ask here is. The Fiddler web proxy intercepts the incoming and outgoing requests, this could add some delay to the request. There is also some discussion thread https://groups.google.com/g/httpfiddler/c/ut7EnElW3nw which talks about request slowdown, but it might not be application in your case as it compares IPv4 vs. IPv6 local stack. Did you try opening a case with Fiddler support forum?

[TommyN]

I'll try the Fiddler support forum. The reason I asked here first is because of the difference between the S3 SDK and the legacy Affirma.ThreeSharp we're replacing. I'm not able to reproduce the issue at home, so I'll try again when I'm back in the office. Feel free to close the issue/question.

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.