a couple of days ago i conducted some scalability tests with the
live555 media server. The computer in test was a quad core that
handle the job pretty well and of course a Gigabit port was used.
For the last test I used several openRTSP clients. The video source
I used was a transport steam file. The normal client downloads an
average of 10Mbit/s (1,3Mbytes/s). For the test I created 68 clients
all connecting to the same live555 server. The connection sequence
was the following, 25 clients, 24 clients, 12 clients and 8. For the
first 49 clients the connection was stable and normal, having a
total throughput of more than 500Mbit/s. However when connecting the
next 12 and 8, the bandwidth was reduced more than 20% for every
client i think. Because testing for one the average speed was less
than 8Mbit/s with a total Throughput from the server of around
500Mbit/s.
Later when the first 25 clients disconnected and the rest remained,
the connection went up reaching almost 750Mbit for 5 minutes and
just for 44 clients, meaning they were compensating I guess for the
stream delay. In the end all the remaining clients had a video file
almost identical to the original one (missing a few seconds maybe).
Why did this happen?
I don't know. You'll have to explicitly measure exactly where in
your system the bottleneck(s) are occurring, and exactly what is
getting overloaded.
Note that there's a lot more in 'your system' than just our software.
In particular, you have operating systems, CPUs, networks, routers,
etc. Any of which could be limiting scalability.
Note in particular that scalability problems with this (and other)
software is often caused by operating-system-imposed limits on the
number of open sockets. Such a limit can usually be increased by
reconfiguring your OS, so that's one of many things that you might
try.
I'm guessing ofcourse this is due to the RTCP protocol.
No, that's highly unlikely. The overhead of RTCP is negligible.
--
Ross Finlayson
Live Networks, Inc.
http://www.live555.com/
_______________________________________________
live-devel mailing list
[email protected]
http://lists.live555.com/mailman/listinfo/live-devel
