Transmission slows down everything on network

[Nemrod]

Do you have tested the latested released ?

I'm currently testing the 1.9 since this morning, of course i need to test it few days but it seems that it cause OS X sleepings and the usual freeze while stopping.

[Nemrod]

All your problems are resolved ?!?

[metaclam]

I'm back because it seems while running transmission (latest release: 1.92/10363) all network traffic throughout my LAN is intermittently slowing to a crawl, with web pages taking minutes to load or timing out.

Previous version of Transmission seemed better, and fixed issues of killing router entirely. (of course I did upgrade my netgear prosafe from 1.x to 2.x, which specifically contained some bit torrent fixes, which might have also helped).

I'm also wondering about whether a high number of "active" transfers matters... I've got 511 transfers. What I don't get is it shows 489 of them as active and 489 of them seeding and 510 of them as "all" with 21 paused. but of course only a small number of those are actually "active" -- most are seeding to 0 of 0 peers. Shouldn't transmission be managing this somehow?

[Ergolad]

x190, can you please describe these settings in more detail? In looking around in the prefs, I wasn't entirely clear where these values should go. I appreciate it! Thanks.

I too am having these issues. I tried some alternative Torrent applications like Vuze, but I really like the straight forward simplicity of Transmission. Hope I can get this resolved.

I am running 1.92/10363 on Snow Leopard and networked with a Linky WRT54GL running the latest stable DDWRT firmware. Things seem fine for a bit, but once Transmission really starts to kick in and transmit the whole network bogs down and all devices have major slowing issues. Turn off Transmission all together and the network returns to normal.

[metaclam]

x190, I followed your suggestions. The first 2 I had, the "10 max active" I didn't have checked. I set that for a while and it seemed to help the network. But unfortunately it also prevented me from seeding new torrents, which were always "waiting to seed". I posed here about that:

http://forum.transmissionbt.com/viewtop ... f=4&t=8048

It just seems to me Transmission has to get a lot smarter about what it seeds. Obviously if you create a seed it should start those and if necessary stop or limit other transfers, no? What does "max active" actually mean? I thought that would mean it would stop seeding if there are 10+ other seeders.

[metaclam]

this is an odd question coming from someone who has used torrents for years, but...

what is "queueing" and "seeding" anyway then? are you "seeding" if there are no connections to you or not? and should that choke a network if you have 500+ torrents "seeding" with 0 connections?

then what is "queueing"? if a "queued" torrent never starts seeding when it's supposed to, what good is it? I presume that doesn't choke a network...

Sorry I am confused about the terminology, but to me it seems like a reasonable usage of a torrent client to do the following:

• have as many torrents available as you want
• limit the number that are actually, actively, seeding, by which I mean uploading data
• always, or have a default option to, prioritize the torrents you create (even if that means stopping others that are going when an upload is requested)
• not kill your network/router under any circumstances
• be able to prioritize trackers in some meaningful way, so that if a high priority tracker has a request, other active torrents pause

[humpake]

I'm experiencing the exact same problem; running Transmission completely bogs up my connection after a moment of use (usually 10-20s). I've tried changing the max-connections (both general and per torrent) and bandwidth use limits, but nothing helps. The exact same settings work in other bit-torrent clients without problems, and have worked in Transmission before upgrading to 1.92 (now running nightly 10433 which didn't help).

My setup is OS X 10.5.8. with Transmissions 1.92+ (10433), my router is a WRT54GL Running Tomato Firmware v1.25.1720.

P.s. Since ping becomes totally unresponsive when tested, most slowing down has been verified with traceroutes where jumps after my router go form 20-30ms to 3k-6k ms. This slowness affect every single computer once Transmission either downloads or seeds on my computer.

[Ergolad]

Still bogged down. Works, but after a while any other network activity slows to a crawl. Though it appeared that turning Transmission off seemed to return the network back to normal, a reboot of my router is the more surefire method of getting things back up and running correctly. I have tried rolling back to the older version of Transmission (1.34) that some have recommended and there is no improvement.

Again I am running 1.92/10363 on Snow Leopard and networked with a Linky WRT54GL running the latest stable DDWRT firmware.

[metaclam]

This is sad... its reached a point that I can't run transmission while I need to use the computer anymore... night only... i sincerely hope the devs fix this sort of issue, and/or clearly explain how to properly set it so that it doesn't choke the routers.

right now set for:
seeding with max 10 active transfers
600 kb/s down, 35 kb/s up
global max: 20 peers
max conn for new xfers: 8

and still can't browse the web without massive lags.

[metaclam]

Try doing a Scroogle search with the following search terms--"linksys WRT54GL +network slowdown". What are your tested bandwidth speeds using speakeasy or speedtest? Do you have any other possible bottlenecks on your network such as usb hubs, etc?

With the number of issues in this and related threads, do you really think it's my network?

I had a comcast guy out who tested everything and replaced a lot of cable with the same results. We bypassed my netgear router entirely with the same results. (slow speeds and packetloss on first traceroute hop -- hop 2 with router and hop 1 without router.) What I didn't tell him is that I was running a torrent client. I know that when i quit Transmission everything goes back to normal.

just now with above settings it took at well over a minute just to load the speedtest.net page. results:

8.55 MB/s dl; 3.08 MB/s upload.

quit transmission, more or less the same results. (a little higher: 9.8 MB/s dl & 3.22 MB/s up). normal tested speeds at non-peak hours are closer to 20 MB/s dl & 4-5 MB/s ul.

But that's not the problem -- it's web surfing that stalls out. pages take over a minute to load while transmission is running and are snappy as expected when its not. you'd think that capping dl at 600 kb/s and ul at 35 kb/s would be well within ok ranges to allow for whatever HTTP packets need to be sent, but that's not the case.

edit:

ok so this link is rather interesting. relates to windows but similar issues affecting web browsing, and also only when running bit torrent. he also has a fairly large home network. I've got at nearly 8 wired devices at home (only 3 of them generally active tho) + 4 or so wireless devices (2 airport expresses always on plus 2 iphones).

http://forums.smallnetbuilder.com/showthread.php?t=1011

so perhaps it's not only transmission but BT more generally? but surely there would be a way for torrent clients to not have this effect on networks?

[drayon]

Metaclam,

Your problem is probably 95% the fault of your router. Basically your router cannot handle many connections that Torrents need. Your router is basically bogged down because it's NAT Table size is too small, it's not refreshing and the device has too little memory to handle the connections your bit torrent is requesting. Nearly all consumer routers suffer the same problem. The WRT54GL has only 16MB of DRam and can handle only 512 connections. In contrast a Cisco 877 or 1801 or Juniper routers have up to 512MB of DRAM handling between 30,000-99,999 connections, these business class routers won't suffer the same slow downs a consumer router suffers.

When choosing a router for torrents you need to find out the 'NAT Table Size' and the amount of 'DRAM' the device has. These specs are not often made available by manufacturers an email to their support is probably needed.

[metaclam]

thanks for the helpful replies y'all.

as for being 95% the router: possibly. but then the there should be a way to limit the number of connections the bit torrent client is requesting that is viable. i fail to see why that's not possible. it should be integrated into the "slow" mode setting which is already nice. when i, or someone on my network, is actively using a web browser, tread lightly, even at the cost of slower seeding and dl speeds. right now i achieve the same thing just by quitting Transmission. is no compromise on transmission's end possible?

as for the router, it's a business class netgear FVG318 VPN router, on firmware 2.x, which was supposed to address some issues with bittorent.

I'd consider replacing the router if I can get one for under $400, has strong wifi and an integrated 8 port switch (which this one has), and someone here can recommend one that fits those two criteria and has enough DRAM and connection handling as you say. Looks like the Cisco models have only 4 port switches and retail well over $500. I know I could add a switch to a router, but that's an extra "hop" and i've been pushing the limits of my networking knowledge dealing with port forwarding and reservation tables and such on just one device – afraid that having two to configure together will create more hassle.

frankly, for the bother and expense, i'd rather just run BT when I'm asleep or gone.

[Nemrod]

Hi,

Did you you test the last release ? Since my rate is not slower than usual but 0

...

[nash8114]

Correct me if I'm wrong, please.
If a NAT table is full, the router responsible for NATing would queue or refuse new connections. Existing connections however wouldn't suffer from the NAT table being full.

What I see on my LAN is the following:
- When I ping my router's LAN IP address, the response time is normal (1ms).
- When I ping the first hop on the ISP network, the response time is 4000+ms.
- I also notice that lag in gaming goes through the roof when I start transmission.
- When I quit transmission, the RTD drops down to normal. When I start it again, RTD goes up in a matter of moments again.

If the NAT table would be full, my existing TCP connections in there would not be affected. New connections would be refused or queued. But NAT tables being full does not increase RTD on an active connection.

My connection's bandwidth is not full, and I see this issue even when I limit the number of connections to 50 or lower.

I have no idea what may be going on, but I do doubt it is NAT table related.

[nash8114]

Looking at the symptoms this doesn't match a "NAT table full"-issue.

In a NAT related issue I'd expect connections to either be refused or delayed (until resources are available).
I haven't seen any connection refusal symptoms.. everything is just really slow.
As for the delay mentioned above, it doesn't match what I would expect to see. And here's why:
When the NAT table is full, existing connections should keep working just fine. New connections may experience delay in being created, but once existing, should work fine.
But I see large delays on existing TCP connections. Gaming gets huge lag. SSH slows down to a crawl. Also FTP Control becomes extremely slow.
This indicates that the issue is not limited to new connections.

I DO see that the delay starts after my router. On my LAN I see no issues at all. Services between my PCs run fine.
That means that the trouble doesn't appear to start on my PC's port. Pings between any LAN devices show no issues.

I have a Thomson TWG850-4U router/cable-modem. I have port 59940 designated for transmission and forwarded this on the router.
When I limit the bandwidth to far below 60% (which is just a rule of thumb, not a law) the problem still persists.
When I limit my max number of connections to 20, the problem still persists (and comes back after a restart of transmission & of the modem)
So what do I see? Running a constant ping I see very high response times (above 5 seconds). Even if the bandwidth would be 90% full (which it isn't by far), response time shouldn't raise more than a few hundred ms.
I also see huge delay on existing TCP connections. A running SSH connection echoes back slow (things I type take a few seconds to show).
Again, this is only towards things beyond the router, on the LAN all is fine.

I'm not sure what can be causing the above symptoms.. anybody else have suggestions?