Plex Transcoder Fork Bombing

Retalak · November 14, 2024, 1:22am

Server Version#: 1.41.2.9200
Player Version#: N/A

It seems that on certain hardware/software combinations, the Plex transcoder can flood the machine with an abnormal amount of threads when running either for background tasks or for a transcoded stream. I have two Plex servers, and it only seems to be happening on one. The machine with the issue has 130+ Plex Transcoder threads (found using ps -L -u USERNAME) for a single 1080p transcode stream. When scanning tasks are being run (intro detection, chapter thumbnail generation, voice activity, etc) I have counted upwards of 300 Plex Transcoder threads running (with no active streams). This is causing issues in particular because the machine the issue is occurring on is shared and has strict user limits in place (1500 processes - which is counted using ps -L so really threads - per user). When this limit is reached, it obviously causes some serious issues including but not limited to a hard lock of the Plex Scanner service that requires a complete restart of PMS to fix. No media will be scanned, whether automatically or manually, until a restart occurs.

In comparison, I tested a 1080p transcode stream on my other server and it only generated around 14 threads.

Server with issue:
Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz
Ubuntu 22.04.4 LTS (I believe it is running in Docker)

Server without issue:
Intel(R) Core™ i5-3570K CPU @ 3.40GHz
Kubuntu 24.04 LTS

Related log errors:
Nov 14, 2024 01:00:21.776 [140385472084792] ERROR - Thread: Couldnt add a new thread to the pool of size 20: thread constructor failed: Resource temporarily unavailable

Here is a thread with related discussion.

Retalak · November 26, 2024, 12:20am

Can I get any help with this? It is making Plex borderline unusable. Any activity that uses the transcoder creates hundreds of threads each. I can easily reproduce by just changing the quality lower on something if staff would like me to send verbose logs.

ChuckPa · November 26, 2024, 1:24am

@Retalak

Which OS distro and version is that running on?

Asking because when you run out of threads, there are some SERIOUS issues.

Are you using a VM?
If so, vCPUs , memory allocated ?

Retalak · November 26, 2024, 1:40am

Ubuntu 22.04.4 LTS (I believe it is running in Docker)
Linux 5.15.0-101-generic

No VM, it’s a shared machine with user limits:

real-time non-blocking time  (microseconds, -R) unlimited
core file size              (blocks, -c) 0
data seg size               (kbytes, -d) unlimited
scheduling priority                 (-e) 0
file size                   (blocks, -f) unlimited
pending signals                     (-i) 1546829
max locked memory           (kbytes, -l) 49513024
max memory size             (kbytes, -m) 4194304
open files                          (-n) 100000
pipe size                (512 bytes, -p) 8
POSIX message queues         (bytes, -q) 819200
real-time priority                  (-r) 0
stack size                  (kbytes, -s) 8192
cpu time                   (seconds, -t) unlimited
max user processes                  (-u) 1500
virtual memory              (kbytes, -v) unlimited
file locks                          (-x) unlimited

Right now there is one 1080p transcode stream and nothing else running (no Plex background tasks or other streams) with 281 transcoder threads.

dbirch · November 26, 2024, 1:48am

@ChuckPa Ive seen the same thing happen occasionally on Windows too, Ive ended up with 20+ transcoder threads that were orphaned from the main plex.

Retalak · November 26, 2024, 1:50am

Just a note, (for me at least) they do go away when the stream or background task in question is over. So they don’t seem to be completely orphaned (maybe the OS is just killing them after the main process stops?). But it just creates an absurd amount of them for every task that uses the transcoder. And it is immediate, as soon as the transcoder starts for a task it immediately generates hundreds of threads.

ChuckPa · November 26, 2024, 1:58am

Let’s investigate.

cat /proc/sys/kernel/threads-max (max threads allowed)
ps -o nlwp $(pidof 'Plex Media Server')

This will tell how many threads can exist and how many Plex currently holds.

Retalak · November 26, 2024, 2:04am

xxxxxxx@xxxx:~$ cat /proc/sys/kernel/threads-max
3093658

xxxxxxx@xxxx:~$ ps -o nlwp $(pidof 'Plex Media Server')
NLWP
 121

I also pulled all of the Plex threads from ps -L -u MYUSER
(this is at the exact same time as the above command, so clearly it is not counting all of these transcoder threads)

3321401 3321401 ?        00:05:31 Plex Transcoder
3321401 3321496 ?        00:00:00 Plex Transcoder
3321401 3321497 ?        00:00:00 Plex Transcoder
3321401 3321498 ?        00:00:00 Plex Transcoder
3321401 3321499 ?        00:00:00 Plex Transcoder
3321401 3321500 ?        00:00:00 Plex Transcoder
3321401 3321501 ?        00:00:00 Plex Transcoder
3321401 3321502 ?        00:00:00 Plex Transcoder
3321401 3321503 ?        00:00:00 Plex Transcoder
3321401 3321504 ?        00:00:00 Plex Transcoder
3321401 3321505 ?        00:00:00 Plex Transcoder
3321401 3321506 ?        00:00:00 Plex Transcoder
3321401 3321507 ?        00:00:00 Plex Transcoder
3321401 3321508 ?        00:00:00 Plex Transcoder
3321401 3321509 ?        00:00:00 Plex Transcoder
3321401 3321510 ?        00:00:00 Plex Transcoder
3321401 3321511 ?        00:00:00 Plex Transcoder
3321401 3321512 ?        00:00:00 Plex Transcoder
3321401 3321513 ?        00:00:00 Plex Transcoder
3321401 3321514 ?        00:00:00 Plex Transcoder
3321401 3321515 ?        00:00:00 Plex Transcoder
3321401 3321516 ?        00:00:00 Plex Transcoder
3321401 3321517 ?        00:00:00 Plex Transcoder
3321401 3321518 ?        00:00:00 Plex Transcoder
3321401 3321519 ?        00:00:00 Plex Transcoder
3321401 3321520 ?        00:00:00 Plex Transcoder
3321401 3321521 ?        00:00:00 Plex Transcoder
3321401 3321522 ?        00:00:00 Plex Transcoder
3321401 3321523 ?        00:00:00 Plex Transcoder
3321401 3321524 ?        00:00:00 Plex Transcoder
3321401 3321525 ?        00:00:00 Plex Transcoder
3321401 3321526 ?        00:00:00 Plex Transcoder
3321401 3321527 ?        00:00:00 Plex Transcoder
3321401 3321528 ?        00:00:00 Plex Transcoder
3321401 3321529 ?        00:00:00 Plex Transcoder
3321401 3321530 ?        00:00:00 Plex Transcoder
3321401 3321531 ?        00:00:00 Plex Transcoder
3321401 3321532 ?        00:00:00 Plex Transcoder
3321401 3321533 ?        00:00:00 Plex Transcoder
3321401 3321534 ?        00:00:00 Plex Transcoder
3321401 3321535 ?        00:00:00 Plex Transcoder
3321401 3321536 ?        00:00:00 Plex Transcoder
3321401 3321537 ?        00:00:00 Plex Transcoder
3321401 3321538 ?        00:00:00 Plex Transcoder
3321401 3321539 ?        00:00:00 Plex Transcoder
3321401 3321540 ?        00:00:00 Plex Transcoder
3321401 3321541 ?        00:00:00 Plex Transcoder
3321401 3321542 ?        00:00:00 Plex Transcoder
3321401 3321543 ?        00:00:00 Plex Transcoder
3321401 3321544 ?        00:00:00 Plex Transcoder
3321401 3321545 ?        00:00:00 Plex Transcoder
3321401 3321546 ?        00:00:00 Plex Transcoder
3321401 3321547 ?        00:00:00 Plex Transcoder
3321401 3321548 ?        00:00:00 Plex Transcoder
3321401 3321549 ?        00:00:00 Plex Transcoder
3321401 3321550 ?        00:00:00 Plex Transcoder
3321401 3321551 ?        00:00:00 Plex Transcoder
3321401 3321552 ?        00:00:00 Plex Transcoder
3321401 3321553 ?        00:00:00 Plex Transcoder
3321401 3321554 ?        00:00:00 Plex Transcoder
3321401 3321555 ?        00:00:00 Plex Transcoder
3321401 3321556 ?        00:00:00 Plex Transcoder
3321401 3321557 ?        00:00:00 Plex Transcoder
3321401 3321558 ?        00:00:00 Plex Transcoder
3321401 3321559 ?        00:00:00 Plex Transcoder
3321401 3321560 ?        00:00:00 Plex Transcoder
3321401 3321561 ?        00:00:00 Plex Transcoder
3321401 3321562 ?        00:00:00 Plex Transcoder
3321401 3321563 ?        00:00:00 Plex Transcoder
3321401 3321564 ?        00:00:00 Plex Transcoder
3321401 3321565 ?        00:00:00 Plex Transcoder
3321401 3321566 ?        00:00:00 Plex Transcoder
3321401 3321567 ?        00:00:00 Plex Transcoder
3321401 3321568 ?        00:00:00 Plex Transcoder
3321401 3321569 ?        00:00:00 Plex Transcoder
3321401 3321570 ?        00:00:00 Plex Transcoder
3321401 3321571 ?        00:00:00 Plex Transcoder
3321401 3321572 ?        00:00:00 Plex Transcoder
3321401 3321573 ?        00:00:00 Plex Transcoder
3321401 3321574 ?        00:00:00 Plex Transcoder
3321401 3321575 ?        00:00:00 Plex Transcoder
3321401 3321579 ?        00:00:00 Plex Transcoder
3321401 3321580 ?        00:00:00 Plex Transcoder
3321401 3321581 ?        00:00:00 Plex Transcoder
3321401 3321582 ?        00:00:00 Plex Transcoder
3321401 3321583 ?        00:00:00 Plex Transcoder
3321401 3321584 ?        00:00:00 Plex Transcoder
3321401 3321585 ?        00:00:00 Plex Transcoder
3321401 3321586 ?        00:00:00 Plex Transcoder
3321401 3321587 ?        00:00:00 Plex Transcoder
3321401 3321588 ?        00:00:00 Plex Transcoder
3321401 3321589 ?        00:00:00 Plex Transcoder
3321401 3321590 ?        00:00:00 Plex Transcoder
3321401 3321591 ?        00:00:00 Plex Transcoder
3321401 3321592 ?        00:00:00 Plex Transcoder
3321401 3321593 ?        00:00:00 Plex Transcoder
3321401 3321594 ?        00:00:00 Plex Transcoder
3321401 3321595 ?        00:00:00 Plex Transcoder
3321401 3321596 ?        00:00:00 Plex Transcoder
3321401 3321597 ?        00:00:00 Plex Transcoder
3321401 3321598 ?        00:00:00 Plex Transcoder
3321401 3321599 ?        00:00:00 Plex Transcoder
3321401 3321600 ?        00:00:00 Plex Transcoder
3321401 3321601 ?        00:00:00 Plex Transcoder
3321401 3321602 ?        00:00:00 Plex Transcoder
3321401 3321603 ?        00:00:00 Plex Transcoder
3321401 3321604 ?        00:00:00 Plex Transcoder
3321401 3321605 ?        00:00:00 Plex Transcoder
3321401 3321606 ?        00:00:00 Plex Transcoder
3321401 3321607 ?        00:00:00 Plex Transcoder
3321401 3321608 ?        00:00:00 Plex Transcoder
3321401 3321609 ?        00:00:00 Plex Transcoder
3321401 3321610 ?        00:00:00 Plex Transcoder
3321401 3321611 ?        00:00:00 Plex Transcoder
3321401 3321612 ?        00:00:00 Plex Transcoder
3321401 3321613 ?        00:00:00 Plex Transcoder
3321401 3321614 ?        00:00:00 Plex Transcoder
3321401 3321615 ?        00:00:00 Plex Transcoder
3321401 3321616 ?        00:00:00 Plex Transcoder
3321401 3321617 ?        00:00:00 Plex Transcoder
3321401 3321618 ?        00:00:00 Plex Transcoder
3321401 3321619 ?        00:00:00 Plex Transcoder
3321401 3321620 ?        00:00:00 Plex Transcoder
3321401 3321621 ?        00:00:00 Plex Transcoder
3321401 3321622 ?        00:00:00 Plex Transcoder
3321401 3321623 ?        00:00:00 Plex Transcoder
3321401 3321624 ?        00:00:00 Plex Transcoder
3321401 3321625 ?        00:00:00 Plex Transcoder
3321401 3321626 ?        00:00:00 Plex Transcoder
3321401 3321627 ?        00:00:00 Plex Transcoder
3321401 3321628 ?        00:00:00 Plex Transcoder
3321401 3321629 ?        00:00:00 Plex Transcoder
3321401 3321630 ?        00:00:00 Plex Transcoder
3321401 3321631 ?        00:00:00 Plex Transcoder
3321401 3321632 ?        00:00:00 Plex Transcoder
3321401 3321633 ?        00:00:00 Plex Transcoder
3321401 3321634 ?        00:00:00 Plex Transcoder
3321401 3321635 ?        00:00:00 Plex Transcoder
3321401 3321636 ?        00:00:00 Plex Transcoder
3321401 3321637 ?        00:00:00 Plex Transcoder
3321401 3321638 ?        00:00:00 Plex Transcoder
3321401 3321639 ?        00:00:00 Plex Transcoder
3321401 3321640 ?        00:00:00 Plex Transcoder
3321401 3321641 ?        00:00:00 Plex Transcoder
3321401 3321642 ?        00:00:00 Plex Transcoder
3321401 3321643 ?        00:00:00 Plex Transcoder
3321401 3321644 ?        00:00:00 Plex Transcoder
3321401 3321645 ?        00:00:00 Plex Transcoder
3321401 3321646 ?        00:00:00 Plex Transcoder
3321401 3321647 ?        00:00:00 Plex Transcoder
3321401 3321648 ?        00:00:00 Plex Transcoder
3321401 3321649 ?        00:00:00 Plex Transcoder
3321401 3321650 ?        00:00:00 Plex Transcoder
3321401 3321651 ?        00:00:00 Plex Transcoder
3321401 3321652 ?        00:00:00 Plex Transcoder
3321401 3321653 ?        00:00:00 Plex Transcoder
3321401 3321654 ?        00:00:00 Plex Transcoder
3321401 3321655 ?        00:00:00 Plex Transcoder
3321401 3321656 ?        00:00:00 Plex Transcoder
3321401 3321657 ?        00:00:00 Plex Transcoder
3321401 3321658 ?        00:00:00 Plex Transcoder
3321401 3321954 ?        00:00:04 Plex Transcoder
3321401 3321955 ?        00:00:04 Plex Transcoder
3321401 3321956 ?        00:00:04 Plex Transcoder
3321401 3321957 ?        00:00:04 Plex Transcoder
3321401 3321958 ?        00:00:04 Plex Transcoder
3321401 3321959 ?        00:00:04 Plex Transcoder
3321401 3321960 ?        00:00:04 Plex Transcoder
3321401 3321961 ?        00:00:04 Plex Transcoder
3321401 3321962 ?        00:00:04 Plex Transcoder
3321401 3321963 ?        00:00:04 Plex Transcoder
3321401 3321964 ?        00:00:04 Plex Transcoder
3321401 3321965 ?        00:00:04 Plex Transcoder
3321401 3321966 ?        00:00:04 Plex Transcoder
3321401 3321967 ?        00:00:04 Plex Transcoder
3321401 3321968 ?        00:00:04 Plex Transcoder
3321401 3321969 ?        00:00:04 Plex Transcoder
3321401 3321970 ?        00:00:04 Plex Transcoder
3321401 3321971 ?        00:00:04 Plex Transcoder
3321401 3321972 ?        00:00:04 Plex Transcoder
3321401 3321973 ?        00:00:04 Plex Transcoder
3321401 3321974 ?        00:00:04 Plex Transcoder
3321401 3321975 ?        00:00:04 Plex Transcoder
3321401 3321976 ?        00:00:04 Plex Transcoder
3321401 3321977 ?        00:00:04 Plex Transcoder
3321401 3321978 ?        00:00:04 Plex Transcoder
3321401 3321979 ?        00:00:04 Plex Transcoder
3321401 3321980 ?        00:00:04 Plex Transcoder
3321401 3321981 ?        00:00:04 Plex Transcoder
3321401 3321982 ?        00:00:04 Plex Transcoder
3321401 3321983 ?        00:00:04 Plex Transcoder
3321401 3321984 ?        00:00:04 Plex Transcoder
3321401 3321985 ?        00:00:04 Plex Transcoder
3321401 3321986 ?        00:00:04 Plex Transcoder
3321401 3321987 ?        00:00:04 Plex Transcoder
3321401 3321988 ?        00:00:04 Plex Transcoder
3321401 3321989 ?        00:00:04 Plex Transcoder
3321401 3321990 ?        00:00:04 Plex Transcoder
3321401 3321991 ?        00:00:04 Plex Transcoder
3321401 3321992 ?        00:00:04 Plex Transcoder
3321401 3321993 ?        00:00:04 Plex Transcoder
3321401 3321994 ?        00:00:04 Plex Transcoder
3321401 3321995 ?        00:00:04 Plex Transcoder
3321401 3321996 ?        00:00:04 Plex Transcoder
3321401 3321997 ?        00:00:04 Plex Transcoder
3321401 3321998 ?        00:00:04 Plex Transcoder
3321401 3321999 ?        00:00:04 Plex Transcoder
3321401 3322000 ?        00:00:04 Plex Transcoder
3321401 3322001 ?        00:00:04 Plex Transcoder
3321401 3322002 ?        00:00:04 Plex Transcoder
3321401 3322003 ?        00:00:04 Plex Transcoder
3321401 3322004 ?        00:00:04 Plex Transcoder
3321401 3322005 ?        00:00:04 Plex Transcoder
3321401 3322006 ?        00:00:04 Plex Transcoder
3321401 3322007 ?        00:00:04 Plex Transcoder
3321401 3322008 ?        00:00:04 Plex Transcoder
3321401 3322009 ?        00:00:04 Plex Transcoder
3321401 3322010 ?        00:00:04 Plex Transcoder
3321401 3322011 ?        00:00:04 Plex Transcoder
3321401 3322012 ?        00:00:04 Plex Transcoder
3321401 3322013 ?        00:00:04 Plex Transcoder
3321401 3322014 ?        00:00:04 Plex Transcoder
3321401 3322015 ?        00:00:04 Plex Transcoder
3321401 3322016 ?        00:00:04 Plex Transcoder
3321401 3322017 ?        00:00:04 Plex Transcoder
3321401 3322018 ?        00:00:04 Plex Transcoder
3321401 3322019 ?        00:00:04 Plex Transcoder
3321401 3322020 ?        00:00:04 Plex Transcoder
3321401 3322021 ?        00:00:04 Plex Transcoder
3321401 3322022 ?        00:00:04 Plex Transcoder
3321401 3322023 ?        00:00:03 Plex Transcoder
3321401 3322024 ?        00:00:03 Plex Transcoder
3321401 3322025 ?        00:00:03 Plex Transcoder
3321401 3322026 ?        00:00:03 Plex Transcoder
3321401 3322027 ?        00:00:03 Plex Transcoder
3321401 3322028 ?        00:00:03 Plex Transcoder
3321401 3322029 ?        00:00:03 Plex Transcoder
3321401 3322030 ?        00:00:02 Plex Transcoder
3321401 3322031 ?        00:00:01 Plex Transcoder
3321401 3322032 ?        00:00:00 Plex Transcoder
3321401 3322033 ?        00:00:00 Plex Transcoder
3321401 3322040 ?        00:01:13 Plex Transcoder
3321401 3322041 ?        00:01:12 Plex Transcoder
3321401 3322042 ?        00:01:13 Plex Transcoder
3321401 3322043 ?        00:01:12 Plex Transcoder
3321401 3322044 ?        00:01:13 Plex Transcoder
3321401 3322045 ?        00:01:12 Plex Transcoder
3321401 3322046 ?        00:01:12 Plex Transcoder
3321401 3322047 ?        00:01:13 Plex Transcoder
3321401 3322048 ?        00:01:13 Plex Transcoder
3321401 3322049 ?        00:01:12 Plex Transcoder
3321401 3322050 ?        00:01:13 Plex Transcoder
3321401 3322051 ?        00:01:12 Plex Transcoder
3321401 3322052 ?        00:01:12 Plex Transcoder
3321401 3322053 ?        00:01:13 Plex Transcoder
3321401 3322054 ?        00:01:13 Plex Transcoder
3321401 3322055 ?        00:01:13 Plex Transcoder
3321401 3322056 ?        00:01:12 Plex Transcoder
3321401 3322057 ?        00:01:13 Plex Transcoder
3321401 3322058 ?        00:01:12 Plex Transcoder
3321401 3322059 ?        00:01:12 Plex Transcoder
3321401 3322060 ?        00:01:12 Plex Transcoder
3321401 3322061 ?        00:01:13 Plex Transcoder
3321401 3322062 ?        00:01:12 Plex Transcoder
3321401 3322063 ?        00:01:12 Plex Transcoder
3321401 3322064 ?        00:01:13 Plex Transcoder
3321401 3322065 ?        00:01:12 Plex Transcoder
3321401 3322066 ?        00:01:13 Plex Transcoder
3321401 3322067 ?        00:01:13 Plex Transcoder
3321401 3322068 ?        00:01:13 Plex Transcoder
3321401 3322069 ?        00:01:12 Plex Transcoder
3321401 3322070 ?        00:01:11 Plex Transcoder
3321401 3322071 ?        00:01:12 Plex Transcoder
3321401 3322072 ?        00:01:13 Plex Transcoder
3321401 3322073 ?        00:01:13 Plex Transcoder
3321401 3322074 ?        00:01:43 Plex Transcoder
3321401 3322075 ?        00:01:43 Plex Transcoder
3321401 3322076 ?        00:01:43 Plex Transcoder
3321401 3322077 ?        00:01:43 Plex Transcoder
3321401 3322078 ?        00:01:43 Plex Transcoder
3321401 3322087 ?        00:00:44 Plex Transcoder
3893471 3893471 ?        00:00:00 Plex Media Serv
3893471 3893472 ?        00:00:04 PMS TimerPool
3893471 3893473 ?        00:00:13 PMS Logger
3893471 3893474 ?        00:00:00 PMS sigwait
3893471 3893476 ?        00:00:43 PMS HttpServer
3893471 3893477 ?        00:00:43 PMS HttpServer
3893471 3893478 ?        00:00:00 PMS HttpServerM
3893471 3893488 ?        00:00:07 PMS HttpClient
3893471 3893504 ?        00:00:02 PMS FileWatcher
3893471 3893505 ?        00:00:01 PMS FileWatcher
3893471 3893633 ?        00:00:21 PMS Timer
3893471 3893648 ?        00:00:00 Plex Media Serv
3893471 3893650 ?        00:00:00 PMS NetService
3893471 3893652 ?        00:00:00 PMS CPM
3893471 3893660 ?        00:00:00 PMS LUM inotify
3893471 3893673 ?        00:00:00 PMS HttpServer
3893471  527355 ?        00:00:00 PMS IAPM
3893471  527356 ?        00:00:00 PMS IAPM
3893471  527357 ?        00:00:00 PMS IAPM
3893471  527358 ?        00:00:00 PMS IAPM
3893471  527359 ?        00:00:00 PMS IAPM
3893471  527360 ?        00:00:00 PMS IAPM
3893471  527361 ?        00:00:00 PMS IAPM
3893471  527362 ?        00:00:00 PMS IAPM
3893471  527363 ?        00:00:00 PMS IAPM
3893471  527364 ?        00:00:00 PMS IAPM
3893471  527365 ?        00:00:00 PMS IAPM
3893471  527366 ?        00:00:00 PMS IAPM
3893471  527367 ?        00:00:00 PMS IAPM
3893471  527368 ?        00:00:00 PMS IAPM
3893471  527369 ?        00:00:00 PMS IAPM
3893471  527370 ?        00:00:00 PMS IAPM
3893471  527371 ?        00:00:00 PMS IAPM
3893471  527372 ?        00:00:00 PMS IAPM
3893471  527373 ?        00:00:00 PMS IAPM
3893471  527374 ?        00:00:00 PMS IAPM
3893471  527375 ?        00:00:00 PMS IAPM
3893471  527376 ?        00:00:00 PMS IAPM
3893471  527377 ?        00:00:00 PMS IAPM
3893471  527378 ?        00:00:00 PMS IAPM
3893471  527379 ?        00:00:00 PMS IAPM
3893471  527380 ?        00:00:00 PMS IAPM
3893471  527381 ?        00:00:00 PMS IAPM
3893471  527382 ?        00:00:00 PMS IAPM
3893471  527383 ?        00:00:00 PMS IAPM
3893471  527384 ?        00:00:00 PMS IAPM
3893471  527385 ?        00:00:00 PMS IAPM
3893471  527386 ?        00:00:00 PMS IAPM
3893471  527387 ?        00:00:00 PMS IAPM
3893471  527388 ?        00:00:00 PMS IAPM
3893471  527389 ?        00:00:00 PMS IAPM
3893471  527390 ?        00:00:00 PMS IAPM
3893471  527391 ?        00:00:00 PMS IAPM
3893471  527392 ?        00:00:00 PMS IAPM
3893471  527393 ?        00:00:00 PMS IAPM
3893471  527394 ?        00:00:00 PMS IAPM
3893471  527395 ?        00:00:00 PMS IAPM
3893471  527396 ?        00:00:00 PMS IAPM
3893471  527397 ?        00:00:00 PMS IAPM
3893471  527398 ?        00:00:00 PMS IAPM
3893471  527399 ?        00:00:00 PMS IAPM
3893471  527400 ?        00:00:00 PMS IAPM
3893471  527401 ?        00:00:00 PMS IAPM
3893471  527402 ?        00:00:00 PMS IAPM
3893471  527403 ?        00:00:00 PMS IAPM
3893471  527404 ?        00:00:00 PMS IAPM
3893471  527405 ?        00:00:00 PMS IAPM
3893471  527406 ?        00:00:00 PMS IAPM
3893471  527407 ?        00:00:00 PMS IAPM
3893471  527408 ?        00:00:00 PMS IAPM
3893471  527409 ?        00:00:00 PMS IAPM
3893471  527410 ?        00:00:00 PMS IAPM
3893471  527411 ?        00:00:00 PMS IAPM
3893471  527412 ?        00:00:00 PMS IAPM
3893471  527413 ?        00:00:00 PMS IAPM
3893471  527414 ?        00:00:00 PMS IAPM
3893471  527415 ?        00:00:00 PMS IAPM
3893471  527416 ?        00:00:00 PMS IAPM
3893471  527417 ?        00:00:00 PMS IAPM
3893471  527418 ?        00:00:00 PMS IAPM
3893471  527419 ?        00:00:00 PMS IAPM
3893471  527420 ?        00:00:00 PMS IAPM
3893471  527421 ?        00:00:00 PMS IAPM
3893471  527422 ?        00:00:00 PMS IAPM
3893471  527423 ?        00:00:00 PMS IAPM
3893471  527424 ?        00:00:00 PMS IAPM
3893471  527425 ?        00:00:00 PMS IAPM
3893471  527426 ?        00:00:00 PMS IAPM
3893471  527427 ?        00:00:00 PMS IAPM
3893471  527428 ?        00:00:00 PMS IAPM
3893471  527429 ?        00:00:00 PMS IAPM
3893471  527430 ?        00:00:00 PMS IAPM
3893471  527431 ?        00:00:00 PMS IAPM
3893471  527432 ?        00:00:00 PMS IAPM
3893471  527433 ?        00:00:00 PMS IAPM
3893471 3186708 ?        00:00:11 PMS GTP
3893471 3186710 ?        00:00:12 PMS GTP
3893471 3188625 ?        00:00:12 PMS GTP
3893471 3234706 ?        00:00:06 PMS ReqHandler
3893471 3315219 ?        00:00:06 PMS GTP
3893471 3315220 ?        00:00:06 PMS GTP
3893471 3315222 ?        00:00:06 PMS GTP
3893471 3315270 ?        00:00:06 PMS GTP
3893471 3315281 ?        00:00:06 PMS GTP
3893471 3318152 ?        00:00:06 PMS GTP
3893471 3320260 ?        00:00:06 PMS GTP
3893471 3320261 ?        00:00:05 PMS GTP
3893471 3320262 ?        00:00:06 PMS GTP
3893471 3320263 ?        00:00:06 PMS GTP
3893471 3320264 ?        00:00:06 PMS GTP
3893471 3320265 ?        00:00:06 PMS GTP
3893471 3320266 ?        00:00:06 PMS GTP
3893471 3320267 ?        00:00:06 PMS GTP
3893471 3320268 ?        00:00:06 PMS GTP
3893471 3320269 ?        00:00:06 PMS GTP
3893471 3320295 ?        00:00:06 PMS GTP
3893471 3323856 ?        00:00:03 PMS ReqHandler
3893471 3323932 ?        00:00:02 PMS ReqHandler
3893471 3404372 ?        00:00:01 PMS ReqHandler
3893471 3404374 ?        00:00:01 PMS ReqHandler
3893471 3404377 ?        00:00:01 PMS ReqHandler
3893471 3404379 ?        00:00:01 PMS ReqHandler
3893471 3404381 ?        00:00:01 PMS ReqHandler
3893471 3404382 ?        00:00:01 PMS ReqHandler
3893471 3404384 ?        00:00:01 PMS ReqHandler
3893471 3404386 ?        00:00:01 PMS ReqHandler
3893471 3404388 ?        00:00:01 PMS ReqHandler
3893471 3404394 ?        00:00:01 PMS ReqHandler
3893471 3404397 ?        00:00:01 PMS ReqHandler
3893471 3404403 ?        00:00:01 PMS ReqHandler
3893471 3404404 ?        00:00:01 PMS ReqHandler
3893471 3404407 ?        00:00:01 PMS ReqHandler
3893471 3404411 ?        00:00:01 PMS ReqHandler
3893471 3404412 ?        00:00:01 PMS ReqHandler
3893471 3404413 ?        00:00:00 PMS ReqHandler
3893471 3404414 ?        00:00:01 PMS ReqHandler
3893471 3404417 ?        00:00:00 PMS ReqHandler
3893471 3404418 ?        00:00:00 PMS ReqHandler
3893471 3404419 ?        00:00:01 PMS ReqHandler
3893506 3893506 ?        00:00:02 Plex Script Hos
3893506 3893542 ?        00:00:00 Plex Script Hos
3893506 3893543 ?        00:00:00 Plex Script Hos
3893506 3893544 ?        00:00:00 Plex Script Hos
3893506 3893545 ?        00:00:00 Plex Script Hos
3893506 3893546 ?        00:00:00 Plex Script Hos
3893506 3893547 ?        00:00:00 Plex Script Hos
3893506 3893548 ?        00:00:00 Plex Script Hos
3893506 3893549 ?        00:00:00 Plex Script Hos
3893506 3893621 ?        00:00:00 Plex Script Hos
3893506 3893622 ?        00:00:00 Plex Script Hos
3893506 3893630 ?        00:00:27 Plex Script Hos
3893653 3893653 ?        00:00:36 Plex Tuner Serv
3893653 3893658 ?        00:00:00 Plex Tuner Serv
3893653 3893659 ?        00:00:01 Plex Tuner Serv
3893653 3893661 ?        00:00:00 Plex Tuner Serv
3893653 3893662 ?        00:00:00 Plex Tuner Serv
3893653 3893663 ?        00:00:00 Plex Tuner Serv
3893653 3893664 ?        00:00:00 Plex Tuner Serv
3893653 3893665 ?        00:00:00 Plex Tuner Serv
3893653 3893666 ?        00:00:00 Plex Tuner Serv
3893653 3893667 ?        00:00:00 Plex Tuner Serv
3893653 3893668 ?        00:00:00 Plex Tuner Serv

ChuckPa · November 26, 2024, 2:08am

PMS normally has about 75 threads running when doing anything.

Mine is completely idle.

[chuck@glockner ~.1999]$ ps -o nlwp $(pidof 'Plex Media Server')
NLWP
  52
[chuck@glockner ~.2000]$

Processes ‘hang around’ (zombies) until the parent process signal handler ‘receives’ the termination message. This normally is processed in microseconds. When the machine is overloaded, they hang around.

You are having the problem with the transcoder or PMS ?
(two completely different programs)

A thought??

You’re running PMS under your UID ?

Retalak · November 26, 2024, 2:13am

@ChuckPa
I see:

vivalarev@salt:~$ ps -o nlwp $(pidof 'Plex Transcoder')
NLWP
 361

Technically it is with the transcoder, but it causes all kinds of problems with PMS in general. For example if I hit my thread limit and get “Resource temporarily unavailable” errors during a library scan, the scanner will get locked up and I have to restart PMS for it to start scanning again - even with a manual scan.

ChuckPa · November 26, 2024, 2:14am

What happens when you restart PMS?

(When you shutdown PMS, do processes stay around?)

Retalak · November 26, 2024, 2:21am

@ChuckPa
I checked after stopping PMS, nothing stuck around.

As soon as PMS started back up again, I checked:

xxxxxxx@xxxx:~$ ps -o nlwp $(pidof 'Plex Transcoder')
NLWP
   1
   1

And then started up a transcode stream:

xxxxxxx@xxxx:~$ ps -o nlwp $(pidof 'Plex Transcoder')
NLWP
 338

It goes back to one immediately after stopping the stream.

Also it seems my PMS thread count has gone down:

xxxxxxx@xxxx:~$ ps -o nlwp $(pidof 'Plex Media Server')
NLWP
  28

ChuckPa · November 26, 2024, 2:23am

Your logs say nothing about the host OS.
What is this running on?

I’m going to check my thread counts just as you have shown

EDIT:

[chuck@glockner ~.2000]$ ps -o nlwp $(pidof 'Plex Media Server')
NLWP
  68
[chuck@glockner ~.2000]$ ps -o nlwp $(pidof 'Plex Transcoder')
NLWP
  62
[chuck@glockner ~.2001]$

Retalak · November 26, 2024, 2:28am

I am pretty sure it is running on the bare machine (in a Docker container I believe). From what I can tell, it’s this machine.

xxxxxxxx@xxxx:~$ hostnamectl status
 Static hostname: REDACTED
       Icon name: computer-server
         Chassis: server
      Machine ID: REDACTED
         Boot ID: REDACTED
Operating System: Ubuntu 22.04.4 LTS
          Kernel: Linux 5.15.0-101-generic
    Architecture: x86-64
 Hardware Vendor: Supermicro
  Hardware Model: PIO-648R-E1CR36L+-ST031

ChuckPa · November 26, 2024, 2:30am

[chuck@glockner ~.2001]$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.5 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.5 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
[chuck@glockner ~.2002]$ uname -a
Linux glockner 6.8.0-49-generic #49~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Nov  6 17:42:15 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
[chuck@glockner ~.2003]$ cat /proc/cpuinfo | grep 'model name' | uniq
model name	: Intel(R) Xeon(R) CPU E5-2690 v4 @ 2.60GHz
[chuck@glockner ~.2004]$ hostctl status
Command 'hostctl' not found, but can be installed with:
sudo snap install hostctl
[chuck@glockner ~.2005]$ hostnamectl status
 Static hostname: glockner
       Icon name: computer-server
         Chassis: server
      Machine ID: 61b618f4171b45a5a30b2b20ec9ccb6d
         Boot ID: 19046d62eccb429c9c5d5ed2bbb0d9ce
Operating System: Ubuntu 22.04.5 LTS              
          Kernel: Linux 6.8.0-49-generic
    Architecture: x86-64
 Hardware Vendor: Supermicro
  Hardware Model: X10SRA-F
[chuck@glockner ~.2006]$

That machine should NOT be on the 5.15 kernel. That’s a problem in 22.04

Retalak · November 26, 2024, 2:32am

@ChuckPa

xxxxxxxx@xxxx:~$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.4 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy
xxxxxxxx@xxxx:~$ uname -a
Linux REDACTED.HOST.NAME 5.15.0-101-generic #111-Ubuntu SMP Tue Mar 5 20:16:58 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
xxxxxxxx@xxxx:~$ cat /proc/cpuinfo | grep 'model name' | uniq
model name      : Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz

Retalak · November 26, 2024, 2:36am

@ChuckPa
Interesting I hadn’t noticed that discrepancy. Are you saying this is a known issue with that kernel version? If so, do you know where I can find documentation on it to convince the server admin to upgrade?

ChuckPa · November 26, 2024, 2:42am

I knew the mobo info looked familiar.

How about this?

This is a machine I administer. It’s running flawlessly.

root@apollo:/mnt# hostnamectl status
 Static hostname: apollo
       Icon name: computer-server
         Chassis: server
      Machine ID: 94e3d6befec0439bb2ae345bc242626d
         Boot ID: 5669129ef07c4fa68bb3c46c988678e1
Operating System: Ubuntu 22.04.5 LTS              
          Kernel: Linux 6.8.0-49-generic
    Architecture: x86-64
 Hardware Vendor: Supermicro
  Hardware Model: PIO-648R-E1CR36L+-ST031
root@apollo:/mnt# uname -a
Linux apollo 6.8.0-49-generic #49~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Nov  6 17:42:15 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
root@apollo:/mnt# cat /proc/cpuinfo | grep 'model name' | uniq
model name	: Intel(R) Xeon(R) CPU E5-2690 v4 @ 2.60GHz
root@apollo:/mnt#  ps -o nlwp $(pidof 'Plex Media Server')
NLWP
  93
root@apollo:/mnt# ps -o nlwp $(pidof 'Plex Transcoder')
NLWP
   1
   1
   1
root@apollo:/mnt#

The admin needs to go to the “hwe” kernel.
They have the wrong one installed for this use case.

(PS: It’s a SWEET motherboard & server. It has 400+ TB of media on it)

If they won’t upgrade the kernel to the HWE kernel, ask to be moved to a machine with a CURRENT kernel on it.

Retalak · November 26, 2024, 2:51am

You may definitely be right, here’s my local machine that is also running Ubuntu and not having this issue:

administrator@kubuntu-plex-server:~$ uname -a
Linux kubuntu-plex-server 6.8.0-45-generic #45-Ubuntu SMP PREEMPT_DYNAMIC Fri Aug 30 12:02:04 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

I have reached out to them and will update this thread once I can test! Thank you!

ChuckPa · November 26, 2024, 2:53am

Ubuntu 22.04 moved to the 6.8 kernel very quickly.
Ubutnu 20.04 barely uses 5.15 on the oldest CPUs only.

Any user I’ve seen on Ubuntu (server/wkstn) with 20.04 is 5.19 or better.

It’s “KUBUNTU” ???

That’s not an vetted distro. (caution)

Topic		Replies	Views
Multiple PlexTranscoder.exe Processes Maxing out CPU When Nothing Should Be Transcoding General Discussions	23	1195	January 8, 2020
Plex hardware transcoding not working Quadro P2000 Plex Media Server server-windows , server-linux , plex-media-player , player-windows	60	1737	December 27, 2021
PMS Phantom Sessions and Locking Up Plex Media Server server-linux	10	118	August 18, 2024
Plex Suddenly Stops Hardware Transcoding Plex Media Server server-linux , apple-tv , server-truenas	69	920	September 20, 2023
Plex seems to transcode entire episodes or movies in 1 go instead of transcoding only when required General Discussions	99	549	January 7, 2020

Plex Transcoder Fork Bombing

EDIT:

Related topics