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[Help] Question regarding transcoding and Firefox - Insane CPU load

nscbox1nscbox1 Members, Plex Pass Posts: 6 Plex Pass

Hi there everyone.

I have a weird "issue" with my server. Or with my clients, I suppose. Specfically the ones using Firefox to access the Plex Web servers. The Plex-transcoder goes totally bananas, and won't stop transcoding the media, until it has reached a 100% in transcoding.

I have observed this in PlexPy, where users using Firefox have transcoded 100% of their media, even though the media barely has started. Here's a few examples: Example 1 - Example 2

The problem with that, is my CPU load is going absolutely crazy, with all my cores getting maxed out, until the transcoder has reached transcoding 100% of the media.

My transcoding settings can be seen > Here! <. These settings have held up to 8 simultaneously transcoding sessions going without any issues - with the users using Chrome/Chromium. No issues at the clients' end, or at the servers end. Buuut then there's 1-2 users using Firefox, and it spikes the CPU for way too long, making the PMS crash after a short while.

I've obviously done the easiest thing: Asking them to stop using Firefox, and using a different client. That has obviously worked, but lets say - hypothetically - they share their user, and forget to tell the next person that they can't use Firefox, and the same thing happens again (e.g. server crash / insane CPU load)?

I don't really want to limit the amount of concurrent streams acceptable, since it runs perfectly and without issues with users using Chromium-based browsers like Google Chrome or SRWare Iron. I've tried changing the transcoding sessions to default, just to check, but to no avail. Firefox seems to require that transcoding-session to get completed, instead of transcoding as the media plays.

My CPU is an Intel Core i7-6700, and with 32GB RAM.. Running with Ubuntu 16.04.2 LTS.

Answers

  • horridwiltinghorridwilting Members, Plex Pass Posts: 8 Plex Pass
    edited April 16

    I can confirm this is also an issue with one of my remote users, using FireFox. It will force it to transcode the stream up to 100% and max out CPU.

    Only appears to be affecting the FF client.

    Plex: Server Version 1.5.3.3580
    Server OS: Windows 10 Pro x64

    I can't put a finger on when it started, exactly, but definitely within the last 1-2 weeks. I know FF updated to v52 recently, maybe something broke?

  • nscbox1nscbox1 Members, Plex Pass Posts: 6 Plex Pass

    @horridwilting said:
    I can confirm this is also an issue with one of my remote users, using FireFox. It will force it to transcode the stream up to 100% and max out CPU.

    Only appears to be affecting the FF client.

    Plex: Server Version 1.5.3.3580
    Server OS: Windows 10 Pro x64

    I can't put a finger on when it started, exactly, but definitely within the last 1-2 weeks. I know FF updated to v52 recently, maybe something broke?

    "Nice" to hear I'm not the only one with the issue. Sad that it is an issue though.

    And yeah.. I have no idea when it started. I just recently noticed my server crashing a lot, and found out about the Firefox-based issue yesterday. I hope someone can help me/us out with this :)

  • srattee21srattee21 Members, Plex Pass Posts: 8 Plex Pass

    I have a Windows server 2012 and same problem.

  • granbebegranbebe Members Posts: 45 ✭✭

    I too have the same issue with Firefox clients.
    My server is 1.5.4 on Linux Ubuntu 16.04 LTS
    I don't know exactly when this transcoding issue started but I would say that it started something like 3 or 4 months ago.

  • nscbox1nscbox1 Members, Plex Pass Posts: 6 Plex Pass

    I'm glad you all replied :). I'm still having this issue, running with version 1.5.5.3634. Not sure if it's an issue on Plex Media Server's end, or Firefox's..?

  • jpurpurajpurpura Members, Plex Pass Posts: 12 Plex Pass

    I've got 1.6.0.3698 on FreeBSD and it happens only on Firefox for me as well.

    I have a 2658v3 so it's not a big deal, but it does eat a good chunk of my 12 cores while it transcodes the whole file!

  • roflserverroflserver Members, Plex Pass Posts: 1 Plex Pass
    edited May 18

    Just adding one more "me too!" to this issue.
    Currently running version 1.4.3.3433 on Windows Server 2012 R2 however have observed this overzealous transcoding occurring with Firefox clients back over many months and old versions.
    Looking at this thread history it appears it's unfortunately still an issue on the most recent version too.

    It's not a major problem for shorter stuff, like individual episodes of TV shows, because they finish buffering fairly quickly... but for movies it'll continue to transcode and buffer all the way to 100% over a long period - sucking up CPU cycles non-stop along the way.

    Maybe this discussion should be moved to a non-OS specific category as it's clearly affecting both Windows and Linux servers.

    Any pointers on this one Plex staff??

  • granbebegranbebe Members Posts: 45 ✭✭

    I happen to have a new friend who is using Opera. Opera has the same issue as Firefox. So it seems the transcoding throttle only with Safari and Chrome.

    I have no idea why (seems to affect both streams direct from my server and streams via plex.tv URL)

  • MattTwinkleToesMattTwinkleToes Members, Plex Pass Posts: 74 Plex Pass

    same, have noticed this. A friend was watching a 3 hour movie remotely and my server was so busy that it could barely sustain a local direct play for me.

    I assumed that firefox was unable to play HEVC.

  • SjarkSjark Members, Plex Pass Posts: 1 Plex Pass

    I also have this issue.
    Plex version: 1.5.5.3634
    Windows Server 2016

    When someone opens a stream with Firefox, all cores goes to max and stays there.

  • granbebegranbebe Members Posts: 45 ✭✭

    Still having the issue.
    Has anybody found a solution or a workaround yet ?

  • nscbox1nscbox1 Members, Plex Pass Posts: 6 Plex Pass

    @granbebe said:
    Still having the issue.
    Has anybody found a solution or a workaround yet ?

    Not yet :(. I ended up buying Ples Pass, so that I could stop the Firefox streams manually, when they appeared.. And then I told all my users not to use Firefox. That seems to have done the trick, but there's no work-around (yet) other than being a bit bossy with your users unfortunately.

  • DuffHQDuffHQ Members, Plex Pass Posts: 90 Plex Pass

    This is also an issue with Safari.. Chrome is the only browser where transcoder throttles.

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