Possible race condition for reading video files written by red5

liuzhe02 / bigbluebutton

Automatically exported from code.google.com/p/bigbluebutton

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Possible race condition for reading video files written by red5 #1807

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago


There may be a race condition whereby for large webcam files, red5 needs some 
time to transfer them from a temporary file to their final location.

In parallel, after BigBlueButton Web detects the meeting has ended, it writes a 
done file that triggers the start of the record and playback worker.

The race condition is if the record and playback worker starts processing the 
video files before red5 is finished writing them, resulting in the webcam file 
being skipped due to zero length.

Reported 

  https://groups.google.com/d/msg/bigbluebutton-users/dajxUikKcvo/NWc5YdnA1YgJ

We need to investigate further.

What is the expected output? What do you see instead?

Please use labels and text to provide additional information.

Original issue reported on code.google.com by ffdixon@gmail.com on 24 Sep 2014 at 8:07

GoogleCodeExporter commented 9 years ago

HI,
Any update for this issue? we have encountered the same problem with another 
recording.

Original comment by b.selmib...@gmail.com on 4 Nov 2014 at 9:08

GoogleCodeExporter commented 9 years ago

Original comment by ffdixon@gmail.com on 13 Nov 2014 at 12:23

GoogleCodeExporter commented 9 years ago

We've added a delay (2 minutes) in the processing scripts in 0.9.0 to make it 
less likely to hit the race condition, but the problem isn't really solved, 
just reduced.

If this delay makes the recordings process more reliably, we're going to push 
the real solution (some sort of synchronization) off to a future release, since 
it'll be very complicated to implement.

Original comment by calvin.walton@kepstin.ca on 13 Nov 2014 at 12:27

GoogleCodeExporter commented 9 years ago

https://github.com/bigbluebutton/bigbluebutton/pull/423

Original comment by calvin.walton@kepstin.ca on 13 Nov 2014 at 12:57

Removed labels: Milestone-Release0.9.0

GoogleCodeExporter commented 9 years ago

Marking this as WontFix as we've since both updated red5 to a newer build and 
added more logic to the record-and-playback scripts to recreate the files.

Original comment by ffdixon@gmail.com on 23 Mar 2015 at 11:21

Changed state: WontFix