SABnzbd Forums

What if you just copied the folder out of Incomplete and then deleted the job all together? Then you could try and salvage anything that actually did get downloaded, while getting rid of the stuck download?

Comes and goes. Will be problem free for weeks, then a dozen jobs will go to 100%, stack up, and not let me click 'Stop.' Still happening.

I traced this a little further since it began to bug my installation, too. For the record: I used to run version 0.7 while coming across this and upgraded to 1.0rc5 while analyzing the issue. It prevailed.

There seems to be something that causes the yenc uudecoding process to become in-cre-di-bly slow (hours per GB on a dual core Atom Server) while bogging down the CPU at 100% load. Since sabnzbd does not appear to be prepared for local decoding to become slower than the actual download, it then appears in the GUI like the download is stuck at "100%" - until all parts of the download have actually finished decoding.

The situation is worsened by the fact that the sabnzbd-assembler is single-threaded, causing other finished downloads to pile up behind the laggy one. Unfortunately they seem to be doing this using some sort of "busy waiting" / polling scheme so that each waiting download uses up its fair share of CPU and slows down the whole process even more .
To make things even worse, sabnzbd does not handle interruptions of this slow decoding thread gracefully (maybe because it is too slow to respond to cleanup signals), so that the often-recommended restarting (e.g. as a part of attempts to "repair" the problem) will actually cause queue corruption and/or data loss in many cases .

As some people in this thread have reported, the problem "repairs itself" if you just leave it alone. That is because - if you don't run out of temporary download space - the decoding WILL eventually finish and the files will process as expected.

Nevertheless, it appears that there is some sort of prevalent yenc decoding problem, probably caused by uploads from specific usenet encoder variants. I have of course made sure that the proper decoding library is installed and found plus I have set up a reasonably big article cache (2G) - with no apparent gain in decoding speed. Since I lack specifc knowledge in the field of usenet binary processing I have not investigated this further. I do have a gut feeling though, that it could be connected to par2 data being recognized as "corrupt".
It would of course be nice to have some sort of indicator in sabnzbd that does inform the user about the decoder lagging behind the actual download and how far it has progressed. Until this is done you will have to to resort to the sabnzbd log which carries a line whenever decoding of the next downloaded part is starting. Also I presume that the assembler queue waiting can be improved easily.

P.S.: Developers may drop me a message and I'll provide you with an nzb that reliably triggers the problem on my installation.

nameBrandon wrote:Anyone ever figure this out? I've got a number of them stuck, they seem to be piling up and then every now and them at seeming random intervals, one will finish.

Are you using more than 1 newsserver?

I've asked to details to be sent to [email protected]
This take of the decoder being the bottleneck is new to me.
I've only seen stuck jobs twice and in those cases the CPU was almost idle.
I'm very interested in the example NZB.

shypike wrote: I've only seen stuck jobs twice and in those cases the CPU was almost idle.

SP, you're referring to CPU, but I'm assuming the subject "Download stuck at 100%" is about the download-completeness, NOT the CPU load.

sander wrote: SP, you're referring to CPU, but I'm assuming the subject "Download stuck at 100%" is about the download-completeness, NOT the CPU load.

That is what the OP claims: 100% CPU load when stuck at 100%

shypike wrote:

sander wrote: SP, you're referring to CPU, but I'm assuming the subject "Download stuck at 100%" is about the download-completeness, NOT the CPU load.

That is what the OP claims: 100% CPU load when stuck at 100%

I don't understand my own pst anymore: I'm quoting "nameBrandon" whose post I can't find anymore. Did his post go away? Or am I mixing things up?

There are two people complaining.
One says there's a CPU problem as well.
I hope to get the offered NZB.

shypike wrote:There are two people complaining.
One says there's a CPU problem as well.
I hope to get the offered NZB.

Hi,

please understand me being a bit reluctant about posting details in public. I have, however, sent you a PM with everything you asked for (hopefully).

Thanks for caring and keep up the good work!

bmx

same issue here

Can you give us some more details?
What version of Sabnzbd? What operating system?
How many servers?
Does it happen for each download?
What happens if you pause and unpause the whole queue?
What happens if you pause and unpause the specific job?