ProppFrexx on a VM - Minimum Requirements

[inl_inc]

Right now I'm running ProppFrexx on a Windows Server 2008 R2 dedicated box (Core i3 2130 3.4GHz 8GB). Thinking of switching it to a virtualized machine running Windows Server 2012 R2.

What are the minimum requirements for ProppFrexx to run on a VM? 2 cores & 2GB - would that be sufficient for a basic set up? I.e. VM dedicated to running a single instance of proppfrexx with 2 cd players, 2 icecast streams (64/128 kbps) and VST effects on the out channel. Or would you recommend allocating more resources? I am a bit constrained with how much power I can assign, as there will be other servers running on that box.

[radio42]

That question is rather hard to answer, as the needed machine resources depend on various factors:
- Memory: mainly the size of your media lib(s)
- CPU: complexity of your setup and mainly the number and type of VSTs/DSPs you are planning to use

By default I would always recommend 4GB and at least 2 cores!

However using Virtual Machines with NO soundcards typically lead to another real-time audio issue - which highly depends on the machine and VM host being used AND also on the utilization of the underlying hardware...

Streaming to a server (e.g. SHOUTcast or ICEcast) always requires real-time processing. Meaning you must send exactly the ‘correct’ amount of data to the server!
If the source client (your VM machine running ProppFrexx) constantly delivers too less data (over time) the server’s audio data buffer will simply underrun.
If the source client constantly delivers too much data (over time) the server’s audio data buffer will simply overflow.
In both cases the connection or the server might either miss or overwrite data within its buffer, or even completely mess up the connection.

We recently did some extensive tests with the developers of the audio engine we are using, and the results are pretty simple to explain: the timing on VMs is terribly bad!
Here are some examples:
- Using a regular PC with a soundcard, any audio processing is done using the soundcard clock: no problems at all, as the soundcard clock is very accurate!
- Using a (local, non-virtualized PC) with NO soundcard: no real problems, the system clock is accurate enough – problems might happen only after months/years!
- Using a Virtual Machine (Win7/2008) with NO soundcard: time differences are up to 15 seconds(!) within 5 hours! This is a problem!
- Using a Virtual Machine (Win8.1/2012R2) with NO soundcard: time differences are better, but might still be +/- 1 second per day! Depending on the streaming server buffer this might be good enough for a couple of months or only a few days.
Different HyperV-Hosts deliver different results.

As a result we can say: a VM by itself (without any soundcard) is simply not suited for real-time audio processing and depending on the OS version and HyperV-Host the results are better/worse.
SHOUTcast has a better buffer underrun/overflow detection implemented – a source client is cleanly disconnected and can safely reconnect.
ICEcast (depending on the fork/version used) has quite a bad buffer underrun/overflow detection and sometimes hardly kills a source client connection.

So please make some serious tests upfront when choosing your VM!, as I can not guarantee a 100% full stable streaming in all cases!
If you need a time limited full license to run your tests please contact me directly or via a PM.

[inl_inc]

Bernd thank you for a great explanation! It will take me some time to get the new server set up and configured.

Really interesting that you brought up the buffer under/over-run issue. Under my current set up, ProppFrexx can remain connected to IceCast for weeks on end. Then multiple disconnects will happen, maybe 1 or 2 an hour for several hours. I was attributing the problem to internet congestion. Actually, this is part of the reason why I am trying to switch to a VM set up - run both ProppFrexx source and the IceCast server on the same box and on the same virtual local network.

Is there a log in ProppFrexx that would show the reason why a connection to the streaming server is dropped? My IceCast logs aren't terribly informative - just a plain Source Timed Out error.

[radio42]

No, ProppFrexx can not log such thing, as it doesn't know and can not know anything about the timing of the streaming server and how much they drift apart.
The streaming server is the only place where buffer under runs/over flows might be detected.

[inl_inc]

In case anyone cares how this set up worked out ...

I haven't experienced a single instance of ProppFrexx/Icecast dropping the connection (been running continuously for 2 months short a week). No timing issues that Bernd pointed out before, however ProppFrexx is running on an pretty powerful 8-core box on the host itself and not as a VM.

[radio42]

Yes, as said, the issue MIGHT happen on VM's especially - however, not on all, but some.

[DJTez]

Hope posting this is this part of the forum is ok. I have been using PPOA for 3 years now. LOVE IT! I have unfortunately forgotten how to configure my streaming data into the Network Streaming Monitor. I have been using Icecast for so long I forgot! here is a screenshot of how I have it cinfigured. can anyone PLEASE help me get it right? I have 6 days until I get a reply. Hopefully Bernd or anyone else totally knowledgeable will answer me asap. Thanks in advance. I have a 2nd question about automating an outside stream to play automatically, but will check thwe FQAQ's first. Cheers everyone and thank you in advance for the help!!

Sincerely,
Tez

[radio42]

At the top right of the dialog you need to select the server type (currently you have selected SHOUTcast), so if your server is an ICEcast server, just select that one
Then the 'Stream ID' field will change to mountpoint - in which you need to specify your specific ICEcast mountpoint name.
That's it...the rest should be okay.

Regarding the outside stream to play automatically:
See here: viewtopic.php?f=9&t=921&p=3273&hilit=mod+stream#p3273

[DJTez]

Thank you for the information. I am using SHOUTCAST for this application. I have an Icecast server already done for years. I just forgot how to set up the shoutcast. Can you check my settings in the picture and see if I need to change anything? Thank you Bernd VERY MUCH!

[radio42]

Is something not working Can you not connect?
What should I check?

Are you using a SHOUTcast v1 or v2 server?
If it is a v1 server, please leave the StreamID empty!
The rest is okay.