Crazy Remote Encoding Super Server?!

[deria]

Hi,

I have an interesting situation. I have a SageTV installation with 4 tuners; I had purchased 4 additional tuners to replace the existing 4 tuners, but for a variety of reasons that appears to no longer be necessary (reverted to an older computer which seems to just plain work better with the original tuners).

So now I have 4 tuners doing essentially nothing. My tinkerer's heart simply won't let sleeping dogs lie, though. I've put them into a second computer, and they work well (so far, anyway).

This just seems like a situation that cries out for some sort of distributed encoding.

Is there any way that I can harness the power of those other 4 encoders? They are PVR150MCE boards, so I know I cannot use the SageTV Recorder module. I heard that you could install a second copy of SageTV though and have it act as a network encoder. How would that work, though?

Would all the shows recorded on the second server be visible on the first? (In the actual TV section, not the movie/video section.)

And would they be stored on the first server or the second?

Basically I'd like the second machine to just be a slave to the first. If something needs to be recorded, and the first doesn't have enough tuners available, it jumps into the breach and saves the day.

Anyone have any ideas?

[Opus4]

There is some info on using 2 full installations of SageTV w/one acting as a network encoder in Appendix G of the manual -- p. 248 for v5.

- Andy

[deria]

Hi Opus4,

Thanks I'll take a look at that. I found a thread that talked about it as well, but the people in the thread didn't seem to have much luck (it was back in January though).

Do you know if the trial-version of SageTV is sufficient for the second server (while I get things setup, I mean; obviously I'd have to buy a second license in order for it to work longer than 15 days). I can't remember if the trial version of SageTV has any limitations. I actually bought it outright as soon as I started using it. I'd rather not buy a second license until after I see it work, though.

[Panzer]

I tried this out in January and it worked great for me. From memory just change enable encoding server to true in the properties. I do remember restarting the main server because I was impatient for it to be detected. After the restart the new unconfigured tuner appeared on the mainserver as "Hauppauge WinTV PVR PCI II Capture #1 on SageServer2"
I'm not using both servers right now because I'm still buying new parts but eventually I'll get back to them.

[Narflex]

You just need to enable encoding server discovery on the 'SageTV Server' and enable the encoding server on the 'network encoder'. This'll work with the trial as well.

[deria]

Cool, I'll give it a try tonight after the hockey game. If this works (and it sounds like it will) and if my signal strength is strong enough to survive that many splits (and it might be; I just picked up an 8-way 2.4ghz splitter) than this will be one rocking system. Since it has its own sound card, I could even use the client part of it as a second tv in the same room (so that I can watch the game while my fiance watches something sickly sweet like Beaches).

Assuming I get this setup, I think I'm going to put together a nice break-down of my system with photos and such. Its rapidly reaching the "perfect PVR" state that I've been aspiring to for years and years.

[deria]

Hi Narflex,

I have a semi-technical question. When using a second server as a network encoding slave, do you know the approximate network bandwidth required?

If I had to guess I would say it would be something along the lines of your_recording_bitrate + some_percent_increment", but what happens if your network lacks the bandwidth? Is the data buffered on the client side until it can be successfully transmitted (ie: you might not be able to watch in real-time, but the show will eventually finish transmitting and be recorded) or would that constitute a failed recording with the result being unwatchable?

The reason I ask is that my network "card" in my main SageTV server is actually a USB-LAN. It is a 10/100 device, but that 100 should be taken with a grain of salt (to say the least). Its more like 20 in my experience. I could take one of the tuners out and put a real network card in, but I would rather not do that unless I actually need to.

Or, if the overhead of having 4 tuners going simultaneously is extreme, I could take a tuner out of each machine and put in a giga-lan card. Then I'd be down to six tuners only (of a possible 8) which is less cool than I'd like.

So I guess my plan is going to hinge pretty heavily on what happens when you have a bandwidth-throtled network. Any insight?

BTW, its *ultra impressive* that this is even possible with SageTV. Features like this really show why SageTV is such a monstrously powerful platform for HTPC enthusiasts.

[deria]

Ok, so I gave this a try. The results are mixed, unfortunately.

There was no trouble getting SageTV to see the encoders on the remote SageTV server. I started some recordings (only one of which was on the network encoder) and all was well... until it was time for the recordings to stop. As soon as the recordings stopped, the CPU usage went to 100% on the main SageTV server and stayed there. When I looked in the task manager, it was SageTVService.exe that was using all of the CPU time.

I stopped that process, rebooted the PC, and tried again with the same result. It doens't seem to be a bandwidth issue, as I was able to later sucessfully start 4 recordings on the network encoder and it didn't seem to be having any trouble keeping up. The problem only arises when the network encoder is supposed to stop recording something.

Any thoughts on what might be happening here? I've attached my sage.properties file if thats any help.

[Narflex]

SageTV logs files would tell us what we need to know probably. Get them from both sides (debug_logging=TRUE)

[deria]

Hi Narflex,

Thanks for the quick reply. I appreciate it.

I'm working on getting the logs now. After restarting everything, I started a recording and it ran to completion without the error occuring. The only apparent difference (aside from the fact that everything was restarted) was that I never actually attempted to watch the recording while it was in progress. So I started another one, started watching it, then jumped to the main menu and left it there (paused, since I do not have menu video turned on). That recording should finish in about 10 minutes and we'll see what happens. Looking at the log files on the slave-side, all I see so far is the occassional timeout message on the encoder socket and and AWFUL LOT of GetFileSize() calls.

As soon as I get the problem to happen I'll post the logs from both sides.

[deria]

Ok, here are the logs.

The show ended at 12:00. The time on both servers is the same (within 1 minute anyway) so the logs should match up reasonably well.

[deria]

I've been playing around quite a bit with this today, and there are three things of note:

1) Its looking more and more like this problem only happens if you actually start watching the show that is being recorded on the encoder. I have started eight separate recordings (four at a time) and allowed them to run to completion. After completion, all is well. All of the failures have been related to a recording ending while a show was being played back. This could be either remarkably good luck, or a useful piece of information.

2) When you look at the logs, you'll see that after the Unsolved History show ends, there is mention of another show. I never told it to record that show (and, indeed, when I rebooted the system it didn't try to). I'm not sure if the reference to the show was just some unrelated communication between the various parts of SageTV or if it means something.

3) I just noticed this; not sure if it makes a difference or not. My primary server is running SageTV 5.0.3 (the beta) and the slave server is running SageTV 5.0.2. I'll upgrade the slave to the proper version regardless, but would it have mattered?

[Opus4]

Originally Posted by deria

2) When you look at the logs, you'll see that after the Unsolved History show ends, there is mention of another show. I never told it to record that show (and, indeed, when I rebooted the system it didn't try to). I'm not sure if the reference to the show was just some unrelated communication between the various parts of SageTV or if it means something.

I don't know anything about your error, but in case you didn't know this part: once you watch a recording in progress, you are in 'live tv mode' until you stop playback, so it will continue to record & playback subsequent shows on the same channel. That would be why you see it continue to the next show when you watch the current one.

- Andy

[deria]

Originally Posted by Opus4

I don't know anything about your error, but in case you didn't know this part: once you watch a recording in progress, you are in 'live tv mode' until you stop playback, so it will continue to record & playback subsequent shows on the same channel. That would be why you see it continue to the next show when you watch the current one.

- Andy

Fair enough, then -- it seems the failure occurs when it tries to do that. As long as I am not watching a show that is recording on a network encoder, all is well. I can watch -other- shows that are recording (ie: shows recording on the primary machine) just fine. Unfortunately, being able to watch stuff while its recording is pretty important in terms of WAF so I'm hoping we'll be able to find a solution.

[pjwerdna]

Originally Posted by deria

Any thoughts on what might be happening here? I've attached my sage.properties file if thats any help.

Erm!

I may be wrong, but dont the video storage paths need to be UNC paths rather than drive letters when you use remote encoders? Otherwise where it gets stored depends on where the encoder is rather than where Sage tells the encoder to record to.

[deria]

Well, with the network encoders setup this way you never specify paths of any kind. They just show up as extra tuners in your tuner list and the recording happens directly to your regular hard disk just as if the tuner was in your machine. Its really completely transparent. (And, with this one exception, works beautifully well.)

I'm hoping that Nerflex will be able to solve the problem by looking at the log files I posted. Its an american holdiay today, though, so I don't really expect that he'll have much of a chance to look at it just yet.

[pjwerdna]

Originally Posted by deria

Well, with the network encoders setup this way you never specify paths of any kind.

If this is correct then the documentation is misleading.

The PDF manual section G points you to http://www.sagetv.com/configuration.html which points you to a text file http://www.sagetv.com/2_papers/NetworkEncoderSetup.txt. This is about Network Encoding using SageRecorder, but the first paragraph says "The one main constraint is that all of the drives that are used by the SageTV server for storing video must be network shares"

Originally Posted by deria

They just show up as extra tuners in your tuner list and the recording happens directly to your regular hard disk just as if the tuner was in your machine.

Of course. But the encoders still need somewhere to record to. If the network encoder is recording to drive C: on the server then the SageTV server must be passing all the data from the encoder to the file. This doesnt seem right to me given what I've read about the forced_video_storage_path_prefix parameter allowing netowrk encoders to be presuaded to record to their local discs etc. (At one point I was going to set up something similar, but decided just to get a better server instead)

[Opus4]

The first part of Appendix G refers to the old way of using SageTVRecorder for the network encoder & doesn't apply to using 2 full installations of SageTV.

Here is a previous comment regarding video recording paths:

Originally Posted by Narflex

With the network encoder discovery you also don't need to worry about mapped drives or UNC paths either.

The old network encoder protocol versions are still fully supported though (and those require mapped drives or UNC paths that match on the encoder & server)

The thing I'm not certain about is what would happen if you do happen to use a video recording path that exists as local paths on both PCs. For now, I would just try not to do that.

- Andy

[deria]

I'm not an expert, but this is the way I see it:

There are "standard" network encoders (the kind referred to by that page) and then there is using a full instance of SageTV as a secondary server. It seems to be two different beasts.

When using SageTV as a second server, I'm not sure whether the data is first recorded to a temporary file and then transmitted or if its never recorded to a temporary file. The final product resides on the primary servers hard drive, though.

I have no shared drives (UNC or otherwise) between those two systems, though, so however its doing it its handling it all by itself. The bottom line though is that part works fine. The only thing that doesn't work is when a recording ends that is being managed by the encoding server while your watching it. Everything else is fine, so I'm not worried one way or the other about the paths. I just want to get that one problem resolved; the rest works beatifully.

EDIT: Ah, Opus4 beat me to it.

[Narflex]

deria,

Can you get me those same kinds of logs again, but let me know at exactly what time the server CPU started to go to 100%. I'm not sure exactly what the problem is yet.

Also, try doing isolated recordings (i.e. there's nothing recorded before or after the recording that's happening) on the network encoders and see if those work OK.