Server suddenly developed lag spikes when playing anything higher than 4Mbps quality

General Discussions
1

I’m not sure what’s going on. I am sure this is a server/network issue but I can’t lay my finger on the source. I used to be able to any movie at max/original quality (most are 12Mbps) without a hiccup. Now it seems like I cannot play most items above 4Mbps without serious lag spikes. I’m not sure when it started since I haven’t been home to actually use full bandwidth much but my fiance tells me it started about a month ago. It also doesn’t seem to matter what I’m playing the videos on - cell phone, tablet, web, Chromecast V1, Chromecast V2 - they all develop the spikes.

My server Specs:
Plex Server: 1.0.3.2461
48GB RAM
Xeon E5-2675 CPU
2x Gigabit LAN connecitons set up as a team.

The big issue is the lagging when to the chromecasts because that’s what we use most. The old version 1 chromecast is the only device connected to that particular wireless network and is about 5 feet from the wireless access point. In the past, with the limits of the 2.4Ghz band, this one couldn’t always do 12Mbps+ but was happy at 8-10, now it’s down to 4 tops. The version 2 chromecast is connected to a different access point on a 5Ghz wireless AC band. This one is about 10 feet from the access point with nothing but the TV between the chromecast and the access point. Both access points are hard-wired to the same central switch as my server, all devices supporting gigabit speeds (tested and confirmed).

I have tried rebooting my PC, the switch, main router and all the access points to see if something was just needing a refresh and that didn’t work. I’ve also tried playing with the transcoder settings, trying Automatic, High Quality, High Speed and Make My CPU Hurt and they all lag.

I’m attaching a log file I got yesterday. I started a new movie (the second Austin Powers) around 3:22pm and it was immediately laggy. Looking through the trace myself, I did see one notice of excessive buffering detected in middle of it spiking but it couldn’t nail down the source. I also see this a lot:
WARN - Held transaction for too long (…\Sync\SyncItemGenerator.cpp:105): 0.140625 seconds

Not sure what that means but there were not devices receiving sync updates at that time. Log is showing the V2 Chromecast. At the time of running this, the only items active on my network were my server, this chrome cast, my cell phone which was controlling the cast and a desktop PC that I was at getting the log files from. CPU usage on my server maxed out at 15%, with only 8% of my RAM used.

Anyone have any ideas on what’s causing my lag spikes? As I said, it used to work great at higher qualities and hardware and software wise the only changes have been plex updates - I haven’t touched anything else. All my hardware passes diagnostic tests which while not perfect give me some confidence that it’s not a failing hard drive or bad stick of RAM.

2

Does anyone have any ideas or know what that warning message means?

3

I have been experiencing the same issue! I would have 7-10 users no issues. Lately 2-3 users and lag! Hope it gets fixed

4

same issue.

5

anyone from plex going to comment?

6

Geeze it sucks paying for software when there’s 0 support…

7

This has been out here for almost 3 weeks with no input from plex. at least 3 people now saw sudden slow down so I’m sure it’s not my network like I suspected and related to the code mentioned in the trace.

8

knock knock.

9

knock knock.

10

Pulled in an update yesterday but still having issues. Where is the support here plex? It has now been more than a month.

11

There is no official support. You rely on users to help if they can. You might randomly get a dev chime in but it’s not common.

12

Yet, how can bugs get fixed if the devs/plex reps don’t even check the forums? This is happening for more than one user and their’s indications in the traces that the code is holding something up.

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@celegorm13 said:
Yet, how can bugs get fixed if the devs/plex reps don’t even check the forums? This is happening for more than one user and their’s indications in the traces that the code is holding something up.

I said it’s not common. Not that it doesn’t happen. Maybe a Plex Ninja can help further.

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Hey there, I was just made aware of this thread. Sorry no one has helped you out before.

I looked at your log and it shows that your Chromecast is trying to direct play 5.1 AAC audio. Is your Chromecast connected to something that can support 5.1 AAC audio? Otherwise, trying to playback an incompatible audio type can result in playback issues.

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Some yes, others no. I don’t think in these traces that the device support 5.1 audio, so it was a little quieter than if it were 2.0 (there was no 2.0 audio option in the file to switch to). But I had played the same videos on that same setup without issues many times before (I’m a big Austin Powers fan).

I was watching some videos yesterday on a non-5.1 TV yesterday. The file again was 5.1 Audio so it was quieter and it was some-what better than it had been in the past (I updated the server on Friday). But it still had issue with buffering. THe odd thing was I was able to get the buffering to stop when I changed from “Original” to 12 Mbps which wasn’t helping before. Not sure if that was a fluke or not though that the 12Mbps setting worked this time where before it wasn’t helping.

I’ve also noticed that some home videos I have that used to play flawlessly before the 1.0 upgrade are very pixelated now when I play - regardless of the destination and quality setting. These videos show that SyncItemGenerator.cpp warning so I don’t know if it it’s related.

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Can you check what 5.1 audio codec you were using? If it’s related to a specific codec we can look if there is a bug with that codec. I have a non-5.1 TV and have not noticed this issue using my Chromecast. If you have a specific file that this always happens with, if you ca get me a sample of the file so I can try to reproduce.

For the home video issue, please provide a sample.

That Sync… error is related to syncing so it’s not impacting these playback issues.

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For the video in the trace, it was H264 for the video, ACC for the Audio. I’ll re-watch it tonight in the same environment to try and recreate to make sure it’s a file issue not a “luck” issue. If it is a file issue, what would be best for getting you a sample?

Also, for the home videos, the pixelation is happening in web viewer and when sent to the Chromecast. If I navigate to the the file in windows and use windows media play to play it, 0 pixelation .

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I’ve seen cases where a device trying to play 5.1 AAC will result in the sound being quieter. 5.1 AAC support was added to PlexWeb recently so it’s possible that when casting, it is keeping the 5.1 AAC, which I don’t think the CC can handle. Let me test this as well and see.

For home videos, ??? Would definitely need a sample.

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The sound being quieter doesn’t actually bother me as it makes sense to me. In my non 5.1 system it’s only got 2 speakers instead of the 6 (if you count the sub) that the stream is intended for so I’m only getting what would be coming out of the front two speakers. When hooked up to a 5.1 system I haven’t seen any sound level issues.

I’m currently watching Austin Powers without Issue. I’ll queue up something else to play when it’s done. Did you still want a copy of the video (or at least a part of it since I don’t compress my videos)? I’ll also get you a copy of the a home video that’s giving issues.

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If the problem is intermittent, then there could be other issues going on. There was nothing really shown in your earlier log, so if you can get me additional logs when it does happen, maybe we can find the cause. The logs from the client you are using when it occurs would also be helpful.