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Zero sized function error on Wowza ec2 instance

Hi,

I sometimes got ‘Zero sized function’ error.

What does the error mean? and how to fix it?

Is it GC problem?

Our service has very few streams. Wowza receives RTMP from iPhone and create HLS files.

We use WowzaStreamingEngine 4.2.0.01, on Amazon EC2 instance which is from pre-build wowza official AMI. The instance type is C4.2xlarge, which has 16GB Ram.

I read an article about performance tuning(https://www.wowza.com/docs/general-tuning), and see conf/Tune.xml.

The article says ’ If you have at least 16 GB of RAM, set your heap size to 8000 MB’ and conf/Tune.xml says ‘${com.wowza.wms.TuningGarbageCollectorConcurrentDefault} - Concurrent Collector’ is recommended.

But the AMI default setting of HeapSize and GC on conf/Tune.xml is ‘${com.wowza.wms.TuningHeapSizeProduction}’ and ‘{com.wowza.wms.TuningGarbageCollectorG1Default}’.

Wowza log shows current max heap size set to 10GB, and GC is G1Default.

Why the AMI default config uses these parameters, not recommended heap size and GC?

Regards.

Hi,

If this is this your own encoder or a 3rd party encoder and it’s not using the Adobe RTMP libraries this will cause problems.

If that’s true, this is most likely some issue with the RTMP implementation that this encoder uses which is a problem on the encoder side not the Wowza side.

Please see if you can reproduce this issue using a different RTMP based encoder such as Wirecast. If you can, please provide the reproducible steps so we can look further.

The Tuning guide says “Don’t set your heap size above 10 GB, as this can lead to long garbage collection cycles/pauses”. The “G1 (Garbage First) collector” is now the recommended garbage collection method and works better than the “Concurrent collector”. The G1 (Garbage First) collector should be used with Java 8 (1.8) which now ships with the Wowza Streaming Engine 4.x installers which is why the default is to now use the G1 (Garbage First) collector.

Regards,

Jason

Hi,

Thank you for your reply.

If this is this your own encoder or a 3rd party encoder and it’s not using the Adobe RTMP libraries this will cause problems.

Yes, I use 3rd party RTMP library, so it will cause problems.

I’m looking for better RTMP library for iOS, but I can’t find yet. Do you know one?

I also understand wowza default config is not a problem, I will keep it.

Regards,

Jun

What problem does the library have?

I will ask the 3rd party developer about the problem, so I want to know the reason of zero sized function error.

regards.

Hi JasonH,

I’m team-mate with tjun84.

Recently, we still got this error at server side. But luckily, we got 2 clips in which, 1 cause the problem, 1 is not. But checking with VLC or FFMPEG, we can’t find any different between these 2 clips. Can you help take a look and guide us how to prevent this kind of error. Right now, it troubling us quite much!

Error case :

[video]https://www.dropbox.com/s/mphpcg0m4yicliw/error.flv?dl=0[/video]

Success case:

[video]https://www.dropbox.com/s/80ozu5lcucajdvy/success.flv?dl=0[/video]