Backend crash while navigating in-progress recording

[Allan]

While watching an in-progress recording, I tried to skip forward and the backend crashed. Not only did it crash, but it also deleted the recording. The program in question (CTV news) is set to only keep 1 recording, but normally the older recording is not deleted until the new recording is completed.

WebOS frontend was in use at the time. Logs spanning the crash are attached (internal IPs obscured).

[mvallevand]

The main problem is your LG client crashed the backend. This is one of the risks of using UI clients they aren't as stable as Kodi. You should probably have posted in the LG client section.

The second problem was that because of the crash a second recording was attempted but it failed for the same reasons we discussed before. https://forums.nextpvr.com/showthread.php?tid=66280 I don't see you attempting to watch the first segment just the second zero byte recording. In fact everything about this is report is a duplicated from that thread you even have the clock jump

2025-05-14 23:07:33.234 [WARN][63] clock jump of 81807.803533 seconds

Which can make it harder for h/w player like the LG to play.


Martin

[Allan]

I feel I posted this in the right place, because the backend crashed. It seems to me that, even though it may have been triggered by the frontend, the backend still shouldn't crash.

I couldn't watch the first segment after the crash because it was gone - the backend seems to have deleted it or possibly overwrote it. I checked storage, and the only thing left was the null recording. I will try a prestartup script as you previously suggested, to see if that works around the null recording issue. I did not try yet because I was gunshy about breaking something.

The only reason I use the LG player at all is because it is the only one I can run in the family room (LG TV with an apple TV) that can play in progress recordings with any competence. The other options available to me (MrMC and the TVos app) are unusable for watching in-progress recordings. It is literally the only WebOS app I use, as I find them generally much inferior to the equivalent apps on the apple TV. There seems to be some movement at KODI to get into the TVos app store, which would be super welcome, as it works very well on the bedroom TV. In the interim, I may pay one of those services that enables you to install using a paid developers certificate, so it lasts for a year.

[mvallevand]

I understand your reasoning since the UI client process runs on the server. Sub has said that many UI client issues could be in libskiasharp which is actually the library that crashes not the bacikend itselt. It'd suggest you report on their github if you are every able to find the faulting application on macOS.

I personally don't like mixing UI client issues with all the backend issues and questions to give them more visibility. As an example direct channel changing in UI clients has been broken for a while, and it appear as a client issue but it can only be fixed on the server.

Martin

[Allan]

To be 100% clear, whatever process may have crashed, dotnet did crash as well.

The crash occurred while I was trying to fast forward through an ad. Then the backend deleted or overwrote the original file that I had been watching. Seems like more going wrong than the process you mentioned.

[mvallevand]

NextPVR is doing nothing wrong, you misinterpreted keep 1, That delete is when recording starts and you can see that the delete in the logs.

2025-05-14 23:24:14.305 [DEBUG][11] About to start recording (6703 on 21): /volumes/TV/nextpvr/CTV National News with Omar Sachedina/Season 2025/CTV.National.News.with.Omar.Sachedina.S2025E104-0.ts
....
2025-05-14 23:24:27.993 [DEBUG][11] - deleting extra recording: /volumes/TV/nextpvr/CTV National News with Omar Sachedina/Season 2025/CTV.National.News.with.Omar.Sachedina.S2025E104.ts (2025-05-15 2:59:00 AM)

I am not sure what happens with the LG client though and why it requested the deleted recording, the session login was odd and it appears to be streaming cached media which is why this should be in the LG section.

Code:

2025-05-14 23:24:29.677    [DEBUG][20]    ClientGetActivity() returning:
{
  "level": 4,
  "url": "/stream?client=211202131e064130add4d176973f6bdf&f=%2Fvolumes%2FTV%2Fnextpvr%2FCTV%20National%20News%20with%20Omar%20Sachedina%2FSeason%202025%2FCTV.National.News.with.Omar.Sachedina.S2025E104-0.ts",
  "screen": "player-PlayerOSD",
  "recording_id": "6703",
  "recording_name": "CTV National News with Omar Sachedina",
  "recording_title": "CTV National News With Omar Sachedina",
  "recording_description": "",
  "recording_duration": "15",
  "recording_size": "0",
  "recording_status": "recording",
  "supports_server_skip": "true",
  "thumbnails": "false",
  "file": "/volumes/TV/nextpvr/CTV National News with Omar Sachedina/Season 2025/CTV.National.News.with.Omar.Sachedina.S2025E104-0.ts"

}

2025-05-14 23:24:30.126    [DEBUG][20]    Got request [x.x.x.98]: /live
2025-05-14 23:24:30.128    [DEBUG][20]    /live?recording=6677&sid=211202131e064130add4d176973f6bdf&growing=true&range=undefined
2025-05-14 23:24:30.128    [DEBUG][20]     - recording: 6677
2025-05-14 23:24:30.128    [DEBUG][20]     - sid: 211202131e064130add4d176973f6bdf
2025-05-14 23:24:30.128    [DEBUG][20]     - growing: true
2025-05-14 23:24:30.128    [DEBUG][20]     - range: undefined
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@1..
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@2
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@3
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@4
2025-05-14 23:24:30.136    [DEBUG][20]    Requested recording not found: 6677

Martin

[sub]

Code:

2025-05-14 23:24:29.677    [DEBUG][20]    ClientGetActivity() returning:
{
  "level": 4,
  "url": "/stream?client=211202131e064130add4d176973f6bdf&f=%2Fvolumes%2FTV%2Fnextpvr%2FCTV%20National%20News%20with%20Omar%20Sachedina%2FSeason%202025%2FCTV.National.News.with.Omar.Sachedina.S2025E104-0.ts",
  "screen": "player-PlayerOSD",
  "recording_id": "6703",
  "recording_name": "CTV National News with Omar Sachedina",
  "recording_title": "CTV National News With Omar Sachedina",
  "recording_description": "",
  "recording_duration": "15",
  "recording_size": "0",
  "recording_status": "recording",
  "supports_server_skip": "true",
  "thumbnails": "false",
  "file": "/volumes/TV/nextpvr/CTV National News with Omar Sachedina/Season 2025/CTV.National.News.with.Omar.Sachedina.S2025E104-0.ts"

}

2025-05-14 23:24:30.126    [DEBUG][20]    Got request [x.x.x.98]: /live
2025-05-14 23:24:30.128    [DEBUG][20]    /live?recording=6677&sid=211202131e064130add4d176973f6bdf&growing=true&range=undefined
2025-05-14 23:24:30.128    [DEBUG][20]     - recording: 6677
2025-05-14 23:24:30.128    [DEBUG][20]     - sid: 211202131e064130add4d176973f6bdf
2025-05-14 23:24:30.128    [DEBUG][20]     - growing: true
2025-05-14 23:24:30.128    [DEBUG][20]     - range: undefined
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@1..
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@2
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@3
2025-05-14 23:24:30.134    [DEBUG][20]    StreamNative@4
2025-05-14 23:24:30.136    [DEBUG][20]    Requested recording not found: 6677

Yeah, that's kind of odd.

I could see this error possibly happening if you're using NextPVR from two places at the same time, say web app and a ui client, and deleted from one. They other client, depending on where it was in the app, might not know about it having been deleted.

[sub]

Martin, did you see an error there anywhere for the backend crash? I had a quick scan through the logs, but didn't notice one.

[mvallevand]

No, I am only assuming a libskiasharp crash because @Allan is not able to get a dmesg like log to confirm.

Martin

[sub]

Yeah, I'm guessing you're right. That is the most likely thing happening.

There has been a few 3.x builds of skia now, so we might try switching to the latest for the next build. Hopefully it'll help with these occasional skiasharp problems.