Continuous buffering and lag as of late

Plex Media Server NAS & Devices
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1

Server Version#: 1.18.0.1913
Player Version#: Plex for LG 4.9.0 (webOS 3.3.0)

On router: Jumbo Frame->disabled

QNAP model: TVS-671
CPU: i5 4590S 3 GHz
RAM: 16 GB

Problem:
Not sure exactly when this problem started but it has never behaved like this before. The issue is that when i play something it starts ok but after a while (few minute) and sometime even from start in some cases the played (on my LG Tv) starts to show buffering.
Right now when i play a movie it plays 2 second and stops 1 second like its “hacking”. As if the data is not being transcoded or delivered to the player in time or something.
Not fully sure when the problem started. Could be a few plex server updates before. Could also be the player itself on the tv which was also updated recently. Sadly i cant downgrade.

I know for sure its not performance on the QNAP since i use barely 25% of the CPU and i have atleast 8 GB of RAM free.
As an example i played this:

plex
plex330Ă—520 12.7 KB

and on plex dashboard i see this (dont show much load):

IMG_0097
IMG_0097816Ă—612 166 KB

I removed all the logs since there were allot of files and played the movie when the issue happened. Also restarted Plex server on NAS + TV to be sure.
Logs.7z (149.7 KB)

I read also that subtitles cause issue here (looked into other threads too but didnt find anything that helps):

Although i never had any issue until just recently. I have the “Burn Subtitles” on Automatic and tried “only image” as well but didnt help. But for sure i dont get the lag or buffering when i remove the subtitle. Considering my PC has lots more power and i have plenty of RAM i dont get why it lags.

I connect everything using cable so there shouldnt be any issue there either.

Just for the sake of testing i also used an AppleTV (new ones, think 3rd gen) to play the same movie with subtitle and it works like a charm. Actually much much better. I kept pushing with fastforward and all and it never slowed down.

I hope someone can figure out what the issue is here. I really like to use my TV for plex as i have done for the last year.

2

The logs seem to be from Sept. 9th, but they refer to EAE can’t write to it’s directory errors.
That is the Easy Audio Encoder program from Plex.

We should get some Plex Media Server logs from the QNAP.
Can you open a web browser to https://app.plex.tv/desktop and go into
Settings - Troubleshooting - Download Logs please? Zip up what it gives you
and attach it with your next reply.

Thanks

3

Thanks for looking at the files. I actually used sftp and copied them directly from
/share/CACHEDEV1_DATA/.qpkg/PlexMediaServer/Library/Plex Media Server/Logs

But here comes the zip file from where you pointed out.
May i ask which file(s) you look into? i try to read some but the info is overwhelming.

Today i just borrowed my daughters appletv and it works just fine. Wish i could use my LG as i use to.
Hope the new logs can show something more. I have not done any changes at all except updating the software.
Plex Media Server Logs_2019-10-13_11-32-28.zip (1.5 MB)

4

I sort by the most recently modified, and look at the

  • Plex Media Server.log
  • com.plexapp.system.log

which usually go back far enough for me to gather evidence by searching for

  • error
  • fail
  • exception
  • warn
  • sqlite3
  • network
  • decision
  • EAE_ROOT

that usually points me to sections of the logs I need to then read the raw stuff around the results.
In your case with low CPU usage, it’s not clear what it will be besides things interrupting the network traffic.

1 Like
5

It looks like Plex is aware of this issue and has released a new update. My problem is, I do not know how to manually update unraid because this update will not work automatically. Plex does not have a direct support avenue as they rely on the community supporting the product.
I have downloaded the new update, but does anyone know where I should copy it to or how to manually update PMS in unraid?

1 Like
6

@alwezhpy hello there, would you please make a new thread for your exact issue?
You’re not likely to get unraid help in a QNAP tagged topic.

2 Likes
7

If I may augment: Getting logs from QNAP can be accomplished with
@dane22’s PMSLibShare package for QNAP.

This allows grabbing the entire Logs directory. Most times, at least 2 Plex Media Server.log files are needed.

1 Like
8

Thanks allot for the great list @nibbles.

@alwezhpy can you please point me to the thread or where they acknowledge this issue?

@ChuckPa i usually ssh and do → zip -r library.zip Plex Media Server
But sure thats a nice info too to know, thanks!

Hopefully we get to the bottom of this issue …

I really dont feel paying 200 dollar for a appletv :slight_smile: although i must admit it works so so much smoother and better in every way.

ps. @alwezhpy: cant you update using the “app center”? i usually go there and stop Plex and install manually.

9

Here are the release notes:
Version 1.18.0.1944

Fixes

Version 1.18.0.1944

    • (LiveTV) Pixellation and stuttering could occur during LiveTV and DVR playback

No app center in unraid, but thx. I have re-asked the question in another forum as requested.

10

Installed Version 1.18.0.1944
Even rebooted the NAS.

Playing Live TV and DVR shows still shows pixellation for about 45 seconds when starting any recorded or live show.
This pixelation only appears when playing through PLEX, all other clients play with zero pixellation.

11

So I’m looking at the last logs you uploaded. I can only find references to you playing videos on an AppleTV.

If you still need help with stuttering from PMS to the LG, let us know.
If so, we could use a restart of PMS, wait 6min, express the failure on the LG, wait 30sec, then please use the web app to Settings - Troubleshooting - Download Logs

thanks

12

I thought it should have the LG playback since i just switched yesterday but sure i will try it tomorrow and upload new files. Thanks allot for the help!

1 Like
13

Here comes the new logs. I did as you asked. Not sure if it helps but in my time at 20:24 it started to lag. Again at 20:25.

Plex Media Server Logs_2019-10-16_20-36-21.zip (3.6 MB)

14

Sir! Thank you for the timing and the new logs. This is what I saw the player and server decide:

Oct 16, 2019 20:20:03.252 [0x7f0003159700] DEBUG - MDE: The Art of Self-Defense (2019): selected subtitle cannot be converted to a compatible format, burning into video stream

So it wants to burn the PGS subs in that file, as they are image based subs. The better type of subs to have would be SRT. Anyway subtitle burns require the video to be transcoded on the CPU.

Could you try changing your Audio & Subtitle settings from Automatic it Manual?
It’s in Settings - Account. That should help you try to stop it.

15

Thanks for the investigation!
I am already using manual
image

But maybe i should remove the checkbox for “Automatically select audio and subtitle track” as well?

Also i have the CPU power so should it not be able to handle it anyway? i dont see my CPU spiking during the lag, is that not strange also?

16

Yes uncheck that so it’s fully manual.

baby steps first :hatched_chick:

17

Sure no problem. Here i played Suit and it started doing the lag at around 22:48 and 22:54

Plex Media Server Logs_2019-10-18_23-56-25.zip (3.4 MB)

18

I’m curious what these addresses are that it’s finding and why they have these names:

Oct 18, 2019 23:18:08.747 [0x7fc421a04740] DEBUG - Detected primary interface: 192.168.2.100
Oct 18, 2019 23:18:08.747 [0x7fc421a04740] DEBUG - Network interfaces:
Oct 18, 2019 23:18:08.747 [0x7fc421a04740] DEBUG -  * 1 lo (127.0.0.1) (loopback: 1)
Oct 18, 2019 23:18:08.747 [0x7fc421a04740] DEBUG -  * 6 bond0 (192.168.2.100) (loopback: 0)
Oct 18, 2019 23:18:08.747 [0x7fc421a04740] DEBUG -  * 11 br0 (192.168.2.120) (loopback: 0)

I think my QNAP uses en0 and lo.

I didn’t see anything terrible in your logs. There were a a few errors, but not at the time you mentioned or nearby. It looks like it’s just doing a transcode and burning in subtitles.

<SessionReport version="2" startTime="0" startTimestamp="Oct 18, 2019 22:45:06.114" key="/library/metadata/10081" session="uur5a32gb1vpldi5wa6dr643" transcode="u13g3x9hot21emix52j9g6k5">
<User id="1" thumb="https://plex.tv/users/3090fd7b2e2d5254/avatar?c=1557071555" title="vampyren" />
<Player address="192.168.2.152" device="" machineIdentifier="yqdyaepceyi4quxrvhktcnxx" model="OLED55E6V-Z" platform="webOS" platformVersion="3.3.0" product="Plex for LG" remotePublicAddress="84.217.46.66" state="" title="LG OLED55E6V-Z" vendor="" version="4.11.1" local="1" relayed="0" secure="0" userID="1" />
<Variants>
<Variant id="360edcb4-e4dc-4082-bf9a-c5e4841bcee9" targetBitrate="16574" context="streaming" sourceVideoCodec="hevc" sourceAudioCodec="ac3" videoDecision="transcode" audioDecision="copy" subtitleDecision="burn" protocol="hls" container="mpegts" videoCodec="h264" audioCodec="ac3" audioChannels="6" transcodeHwRequested="0" transcodeHwFullPipeline="0">

Maybe an employee will stop bye and offer suggestions.

19

I’m curious about the adapter names as well.

  1. bond0 = first bonded adapter
  2. br0 = first (and pre-created) virtual bridge adapter

QTS 4.3 and above use eth for the adapter and qvs for the virtual switch names.

I have the 4 onboard (eth0 - eth3), the 10 GbE at eth4. eth4 feeds the virtual switch and IP is attached to qvs0.

Had you not stated this is QNAP, I would have presumed Synology or other distribution.

To the matter at hand, given both bond0 and br0 are on the same subnet, default TCP packet handling is going to try and use both if the destination is also on 192.168.2.x

It does this because the configuration defaults to a metric (cost) of 1. Linux will always favor the path with the lowest cost. If cost is the same for two paths, it will assume both are valid and use both.

This could easily be the lag you’re seeing because it’s attempting to send on br0 which likely goes nowhere. Not being able to resend, it jumps back to bond0 and then ultimately does get sent.

Does this seem to describe what is being seen?

20

Thanks for the findings. Not sure i understand every detail but to explain about my network setup i can share this :
image

Basically my NAS uses 2 ETH port in trunked mode (192.168.2.100).
My VM’s uses the other address 192.168.2.120 (as you say feeds my virtual switch). So Plex should always be using 192.168.2.100.

I never changed anything and it use to work before but maybe my network configuration is wrong to begin with. Appreciate some tips. I have QTS 4.4.1.
I have looked through the settings and cant see what i should change to be honest.