I have setup Wowza Streaming Engine 4.4.1 on Linux 64bit Mem 126GB CPU 24 and Wowza Streaming Engine 4.0.1 on Linux 64bit Mem 126GB CPU 24 . I have enabled transcoder, transrate and SMILs for live feeds. SMILs are working fine on Wowza Streaming Engine 4.0.1 on Linux 64bit Mem 126GB CPU 24 with same configurations as on Wowza Streaming Engine 4.4.1.
But when playing SMIL on Wowza Streaming Engine 4.4.1 its working fine for 7 live feeds but when feeds are increased to 8 or 9. Video started to stuck while audio keeps on playing.
I don’t know whats the issue here please guide me in resolving this issue. Also i have seen below message in logs.
2016-10-26 22:36:29 IST comment server INFO 200 - TranscodingSession.updateBehindFilter[live/definst/mYstream]: Video behind filter state change. New state: SKIP4FRAME - - - 307.664 - - - - - - - - - - - - -
2016-10-26 22:36:30 IST comment server INFO 200 - TranscodingSession.updateBehindFilter[live/definst/my]: Video behind filter state change. New state: KEYFRAMESONLY - - - 308.775 -
The source of the problems that you are seeing is that your Transcoder is overloaded.
Seeing SKIP1FRAME, SKIP2FRAME, SKIP4FRAME, KEYFRAMESONLY, or ALLFRAMESOFF signals that transcoder is overloaded and is skipping frames in an attempt to keep up with your live feed. This will fill the java heap rapidly which can cause Wowza Streaming Engine to restart. You need to look at tuning Wowza Streaming Engine performance on your system.
Please check your system usage while transcoding is in action using top, htop, lotop vmstat, netstat, or whichever monitoring tool works best for you. You should also look at our set of benchmarks that we have performed with Transcoder.
I hope that this answers your question as to why your system is having issues.
And yes you are right we were using 20 live feeds with transcoder on single server and transcoder was overloaded. Our CPU utilization was at 90% during transcoding. We did performance tunning as well but issue was still there.
So finally we splitted 20 live feeds on 3 different Wowza servers and its working fine now. The main issue was of transcoder overloading and also because we were using low bitrate and low resolution source feed and from transcoder trying to get high bitrate stream with high resolution due to which transcoder was getting overloaded.