Transmission still hangs horribly

Ask for help and report issues not specific to either the Mac OS X or GTK+ versions of Transmission
jimmy_carter
Posts: 1
Joined: Sun Dec 05, 2010 11:44 am

Transmission still hangs horribly

Post by jimmy_carter »

Hi folks
On Linux transmission (used from 1.x up to 2.11) is arguably the best torrent client, yet be it under Ubuntu or Fedora or Debian 32 or 64 bit it (the Gtk interface at least) still hangs often when downloading more than like 2 torrents at once (I got Core i5 750, 4 physical cores).
So the question is, are the devs giving in it's a bad issue and needs to finally be solved asap or is it still perceived like a minor issue to them?
I've found a lot of threads on this issue from different years and the devs seem to have failed to address such a critical issue, I'm not ranting, I'm simply amazed.
rb07
Posts: 1400
Joined: Sun Aug 24, 2008 3:14 am

Re: Transmission still hangs horribly

Post by rb07 »

The problem is reports like yours: they contain no useful information.

Another point of view which I often find: there is a 100:1 proportion of people using it with no problem, to people that find a problem like yours.

So, first stop: How to report a bug.

If users don't say how to reproduce a problem, developers can't do anything, not even analyze the problem.
Rolcol
Posts: 337
Joined: Sun Aug 10, 2008 8:00 am

Re: Transmission still hangs horribly

Post by Rolcol »

How fast are the download speeds combined? It may be disk io that's causing Transmission to block until it's done. Have you tried modifying the cache size preference in the settings.json file?
DJArty
Posts: 5
Joined: Sat Nov 13, 2010 10:03 pm
Location: Kharkiv, Ukraine

Re: Transmission still hangs horribly

Post by DJArty »

Rolcol
"cache-size-mb": 2,
it must be more big or little?

Have some hang problem on MIPS devise WDTV Live if download speed set more then 850Kb/s (but can be.. 5-8Mb/s)
Look like very big aggressive i/o loading... load average more then 3.5
versions 2.03 - 2.11 (don't know about earliest)
rb07 wrote:there is a 100:1 proportion of people using it with no problem
So many people not have download speed more then 10Mbit/s so looks like dont have the problems.
More download speed - more problems :)
Jordan
Transmission Developer
Posts: 2312
Joined: Sat May 26, 2007 3:39 pm
Location: Titania's Room

Re: Transmission still hangs horribly

Post by Jordan »

Yes, you should increase the cache size if you're downloading at that speed.
DJArty
Posts: 5
Joined: Sat Nov 13, 2010 10:03 pm
Location: Kharkiv, Ukraine

Re: Transmission still hangs horribly

Post by DJArty »

ok, thanks for quick reply..
But what max size you can recommend for emb. device with total 256Mb of memory... :wink:
No info in wiki about cache-size-mb
And ... hm ... info about 2.10 (release notes) "Small memory cache to reduce disk IO" is it the same? :shock: (so need small or big cache?)
Rolcol
Posts: 337
Joined: Sun Aug 10, 2008 8:00 am

Re: Transmission still hangs horribly

Post by Rolcol »

256MiB is not terribly low. Would an extra 8-16MiB of memory usage in Transmission disrupt the system? I have mine set to 8MiB of cache ("cache-size-mb": 8,) and all fine. The higher your speeds, the bigger that number should be.

And yes, this is the same feature in 2.10's changelog.
vevs
Posts: 1
Joined: Thu Dec 30, 2010 2:49 pm

Re: Transmission still hangs horribly

Post by vevs »

I have set cache-size to 16 (WDTV Live). But still have system hangs at speed over than 1.5 - 2 megabyte :(
Rolcol
Posts: 337
Joined: Sun Aug 10, 2008 8:00 am

Re: Transmission still hangs horribly

Post by Rolcol »

Does the CPU spike? Is it at specific intervals?
astrocrab
Posts: 3
Joined: Sun Jan 16, 2011 10:16 am

Re: Transmission still hangs horribly

Post by astrocrab »

i have same problem as a topic starter. transmission periodically hangs for 10-15 seconds when seeding several torrents.
disk i/o is not a problem, because it is 4 disks raid0 with 450 mb/s transfer rate. 6 cored, 12gb ram, swap turned off.
szafran
Posts: 33
Joined: Sat Oct 13, 2012 3:06 pm

Re: Transmission still hangs horribly

Post by szafran »

Same here... I think this is because of some kind of slow hashing or something like that.
My NAS specs: Ubuntu x64 Server, AMD Phenom x6 (3,2GHz x 6 cores), 16GB RAM, 3x500GB os drives (RAID0), 13x2TB data drives (RAID5).
I've had a 10mbps connection, and cache set to 256MB - that was ok.
At the beginning of the month it went up to 20mbps, no change to the cache size - there was some throttling, speeds only up to 1,8MB/s
Today I went up to 64mbps (so about 8MB/s) - speeds only up to 1,8MB/s with cache size set to 256MB.
I've tried setting cache to different values up to 2048MB.
The higher the value, the more time it took untill Transmission started to choke and hammer the CPU.
Now I'm at 16MB cache size, speeds up to 8MB/s (but most of the time 6-7MB/s) - there's more disk IO, but my arrays can handle it without problems.
Transmission still chokes from time to time.
szafran
Posts: 33
Joined: Sat Oct 13, 2012 3:06 pm

Re: Transmission still hangs horribly

Post by szafran »

With latest svn update some things seem to be better.
The speeds are more stable, but the CPU usage by one of the Transmission threads is still high (95-100% always while downloading).

I've checked that now there is a newer svn version.
Don't have anything in the queue now, but I'll check and report if something is better/worse.

Edit:
So I'm on svn r13641 - the speed sare even more stable now, but the CPU usage is still high (same as before).
szafran
Posts: 33
Joined: Sat Oct 13, 2012 3:06 pm

Re: Transmission still hangs horribly

Post by szafran »

Nope, was wrong. The speeds go right down to ~2MB/s when more than 1 torrent is active, and CPU usage is sky high.
Tried different settings - nothing helps.
And since the problem is not fixed after 2 years (date of the first post in this topic), then there's no point in waiting for a fix now.
Anyone has any info on a more optimized client (with shell and web access) ?
szafran
Posts: 33
Joined: Sat Oct 13, 2012 3:06 pm

Re: Transmission still hangs horribly

Post by szafran »

Why ?
Because some proggy is to slow ? Weird way of working things out. With that thinking we would have regular 56k modems, and PCs with 100MHz and 128MB RAM - just because you can wait for a small amount of data to DL for weeks.

The reason why I got a >10mbit connection was to get much less wait times.
Active connections on my current 1 torrent in Transmission is less than 20 -> speed ~1,8MB/s (and sky high CPU usage)
Same torrent on uTorrent on my Windows laptop ~20 connections -> speed ~7,5MB/s (and minimal CPU usage)
And yes I've seen that there is a uTorrent version for Linux, but I don't want to use a client with closed code (free, but closed - smells fishy ;P )
szafran
Posts: 33
Joined: Sat Oct 13, 2012 3:06 pm

Re: Transmission still hangs horribly

Post by szafran »

Found the problem.
It's something that takes care of torrent parts.
When downloading smaller torrents with parts around 2000-3000 then everything goes nice (CPU usage for transmission is ~60-80%), but with higher part counts (say ~16000) things go totally wrong (download speeds are low and CPU usage is maxed out).
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