Slow downloads with sabnzbd 3.1.1

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mesa57
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Slow downloads with sabnzbd 3.1.1

Post by mesa57 »

We have updated spotnet to release 1.9.0.6 and included sabnzbd 3.1.1 with it.
Now we are getting complaints from high-speed downloaders (fiber) that download speeds dropped.
For instance from 100 MB to 65 MB.
In our team nobody has fiber available, so we cannot test this ourselfs.
But some reports indicate slower performance :

Sabnzbd 3.1.1
Image

Sabnzbd 2.3.3
Image

Should we revert to sabnbd 2.3.3 ?
Last edited by mesa57 on March 8th, 2021, 9:50 am, edited 1 time in total.

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safihre
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Re: Slow downloads with sabnzbd 3.1.1

Post by safihre »

Try 3.2.0 :)
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mesa57
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Re: Slow downloads with sabnzbd 3.1.1

Post by mesa57 »

Sabnzbd 3.2.0 also gives lower numbers :
Image
We have asked a high-speed downloader to do a test with 2.3.2 and if possible with 3.2.0

Puzzled
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Re: Slow downloads with sabnzbd 3.1.1

Post by Puzzled »

It's probably Python 2 / 3 related.

safihre: I read about os flags and I found that adding os.O_BINARY to os.open() in diskspeedmeasure would increase the write speed by an average of 44% on my SSD drives. I'll experiment a bit with it, please let me know if you already know a reason why it can't be used. I think it's Windows only but maybe there's something similar for other OSes.

Edit: It may only be the test that is affected because normally files are opened with open() in binary mode.
Edit 2: open() in binary mode is actually much faster than os.open(), even when writing for 10 minutes to avoid buffering, so no help there.
Last edited by Puzzled on March 8th, 2021, 3:31 pm, edited 1 time in total.

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safihre
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Re: Slow downloads with sabnzbd 3.1.1

Post by safihre »

I'm not quite sure what these screenshot have to do with slower speeds though? They are just merely diagnostic tools to diagnose big problems, for example write speeds of 1MB/s. They are not meant as performance tools.

Since 3.x has been out for a while, if we really had dramatic speed reductions the forums would be full of it.

So usually these problems can be reduced to other issues with the setups that were just highlighted by the changes in the way we use memory. Before we would prefer to fill up the memory to the absolute maximum before writing to disk, now we stay much closer to writing to disks. So slow disks are much more often resulting in problems.
This is just an example.
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mesa57
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Re: Slow downloads with sabnzbd 3.1.1

Post by mesa57 »

@safihre : the problem only was reported by several high-speed downloaders (> 65 MB). Lower speeds are not affected.
Meanwhile one of our users was willing to execute a test with sabnzbd 2.3.2 ánd sabnzbd 3.2.0
In both cases downloads speeds where OK. He even reported that sabnzbd 3.2.0 seemed to be more stable.
So we decided to switch to 3.2.0 as the problem only seems to be present in 3.1.1

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safihre
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Re: Slow downloads with sabnzbd 3.1.1

Post by safihre »

Great :)
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sander
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Re: Slow downloads with sabnzbd 3.1.1

Post by sander »

@mesag57

SAB 2.3.2 was released in 2017, and 3.1.1 was released in 2020 ... with 11 releases in between.

My advice/request to you: keep up to date with SAB releases. That way, if you discover something, it's easier to analyze & pinpoint.


Snippet of release history

26-02 SABnzbd 3.2.0
12-11 SABnzbd 3.1.1
17-10 SABnzbd 3.1.0
01-09 SABnzbd 3.0.2
18-08 SABnzbd 3.0.1
02-08 SABnzbd 3.0

05-'19 SABnzbd 2.3.9
03-'19 SABnzbd 2.3.8
01-'19 SABnzbd 2.3.7
12-'18 SABnzbd 2.3.6

mesa57
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Re: Slow downloads with sabnzbd 3.1.1

Post by mesa57 »

Sander : fine advice, but we cannot issue a new release for spotnet every time sabnzbd changes.
When we have a new release we always update sabnzbd to the newest at that moment available.
Btw. the previous version which we included in spotnet was 2.3.9 (from 2019)

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