[Webkit-unassigned] [Bug 195451] New: Safari sometimes (1%) fails relay loopback test

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=195451

            Bug ID: 195451
           Summary: Safari sometimes (1%) fails relay loopback test
           Product: WebKit
           Version: Safari 12
          Hardware: iPhone / iPad
                OS: iOS 12
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: WebRTC
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: daginge at confrere.com
                CC: youennf at gmail.com

Created attachment 363997

  --> https://bugs.webkit.org/attachment.cgi?id=363997&action=review

Sample call with the failure

We're seeing a 1% failure rate when performing a relay loopback test on iOS devices running Safari 12 in production.

The issues is that one peer connection is able to get a relay candidate, while the other times out. This is happening at the same time, on the same device, so there is no reason why only one peer connection can get a relay candidate and not the other. Both peer connections are configured with an iceTransportPolicy to only gather relay candidates.

Attached I have a sample log of this happening, please view it at https://fippo.github.io/webrtc-dump-importer/rtcstats

As you can see from PC_0 and PC_1, they attempt to connect to each other, and PC_1 gets an onicecandidate as expected, while PC_0 just times out and generates a null candidate. Neither peer connection goes to the failed ice connection state as expected.

We have observed this in 1% of all loopback tests done with iOS 12 and Safari 12.x (we have the most data from 12.1.2 and 12.1.4).

Let me know if you need additional debug details, hopefully the attached log may give enough insight into this issue happening to discover what's going on. Smells like a race condition to me...

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20190308/18c6b7c9/attachment-0001.html>