Deluge causing serious netlag, even if settings should be ok

[Ux64]

I'm using Deluge with Ubuntu 8.10 64bit. And I often encounter serious netlag when using Deluge. Even download and upload limits are ok. ~70% of the maximum bandwidth. I really wonder why internet browsing becomes so laggy even if there is (or should be) free bandwidth. When ever I run speedtest.net test during this lag. I often get download speeds like 6000 Kbps and upload speed like 200 Kbps. AFAIK, it should be enough for light browsing?

That's why I wonder if it has to so something with Linux? What is suitable number of connections? And if overhead caused by those connections not "transferring payload (the file)" but synchronizing information for big swarm (who has which blocks) causes some uncounted overhead?

My current connection limit is 300, let me know if it's way too high for 8/1 Mbps connection. Download limit is 700 Kbytes/s (leaves something like 130 free) and upload limit is 60 Kbytes/s, leaves something like 20-28 free.

So is my upload rate still too high? Or do I simply have too many connections. I know this is kind of FAQ stuff. But I haven't figured out what is causing the ultimate lag during browsing. In my mind everything should be "book perfect" and yes, there is no other traffic on this connetion to cause any extreme lag. I earlier suspected that the Peers list might be swamping NS server or something, but Andar confirmed that's not the case.

- Thank you!

[andar]

I'm using Deluge with Ubuntu 8.10 64bit. And I often encounter serious netlag when using Deluge. Even download and upload limits are ok. ~70% of the maximum bandwidth. I really wonder why internet browsing becomes so laggy even if there is (or should be) free bandwidth. When ever I run speedtest.net test during this lag. I often get download speeds like 6000 Kbps and upload speed like 200 Kbps. AFAIK, it should be enough for light browsing?

That's why I wonder if it has to so something with Linux? What is suitable number of connections? And if overhead caused by those connections not "transferring payload (the file)" but synchronizing information for big swarm (who has which blocks) causes some uncounted overhead?

My current connection limit is 300, let me know if it's way too high for 8/1 Mbps connection. Download limit is 700 Kbytes/s (leaves something like 130 free) and upload limit is 60 Kbytes/s, leaves something like 20-28 free.

So is my upload rate still too high? Or do I simply have too many connections. I know this is kind of FAQ stuff. But I haven't figured out what is causing the ultimate lag during browsing. In my mind everything should be "book perfect" and yes, there is no other traffic on this connetion to cause any extreme lag. I earlier suspected that the Peers list might be swaming DNS server or something, but Andar confirmed that's not the case.

- Thank you!

Try reducing the number of connections since this can cause problems with some routers as they just cannot handle the load. Either that, or you could try some QoS (reduce bittorrent priority) on your router.

[Ux64]

Try reducing the number of connections since this can cause problems with some routers as they just cannot handle the load. Either that, or you could try some QoS (reduce bittorrent priority) on your router.

I'm using bridged connection. So it's not about "cheap home" routers NAT table being clogged up with DHT(UDP) or TCP connections.

I guess there is some "unaccounted" overhead traffic related to high number of connections and dht (?). But that's just the problem. Even if there IS free bandwidth something is causing other stuff to get slow. I could think about operating systems TCP Stack starting to suck or so. But it's linux stack and used often with servers and high connection numbers so it shouldn't be the cause.

Especially browsing becomes very slow and usually the DNS request part is the slowest part. When ever data starts to flow. Like opening big JPG etc it'll come properly to home.

Another thing that is affecting this might be Ubuntu's "slow start" implementation, so tcp window is very small. But because my connection isn't swamped (low ping latency) it shouldn't be the reason for this problem.

I wonder if Windows users are affected in a same way with similar kind settings setup and evironment?

[ottk3]

i've the same problem, but i don't know if it is a Deluge or a Linux problem. In my home network there are 4 Windows machines, 1 Debian machine (running Deluge) and my Ubuntu workstation. While Deluge is running browsing with my Ubuntu workstation becomes pretty laggy, sometimes the whole internet connection seems to be lost. All Windows machines haven't these problems, there internet connection still runs perfectly.
If i kill Deluge i have no more problems with my Ubuntu connection? Pretty wierd...

[Ux64]

i've the same problem, but i don't know if it is a Deluge or a Linux problem.

Same here, that's why I'm wondering here. Because I simply can't figure out the exact reason.

Even if I drop download to 100 Kbytes/s and upload to 30Kbytes/s, browsing is still very laggy. Even now there should be plenty of downstream free and even 50% of upstream free. But still stuff isn't working properly.

I guess there must be quite much some "unaccounted" traffic? Could it be DHT? Is it's bandwidth consumption monitored? Or something else, which I don't know about. First I though it could be "peer 2 peer" coordination traffic, which really isn't "payload" traffic. If it could swamp upstream with 300 connections?

I would really love to hear comments from other Ubuntu / Linux - Deluge users. Do you have similar problem?

- Thanks!

[Ux64]

Update. Right now I'm experiencing extremely slow DNS (or at least Firefox looking up phase) and current deluge stats say...

Only 45 connections
Download 84 KB/s (~ 10%)
Upload 56 KB/s (~60)

And still DNS is extremely slow. But all problems are gone if I close deluge.

To confirm that it's not about upstream. I'll now drop upload to 10KB/s.

And this is a problem which I have been monitoring for a long time. My best guess is that there is a lot of some "unaccounted" traffic. Does it count UDP traffic?

I don't know if Ubuntu's System Monitor is perfect. But it also shows values which are in range with the limits I set. (With old versions there was more traffic than the limits allowed).

[Ux64]

I managed to get rid of excessive lag, by setting upload rate limit to about 50% from true maximum. I really wonder what's causing that big "off set".

So, if you're experiencing lag, just lower upload rate "enough", even if it would go ridiculously low.

[Ux64]

Now because latest version of Deluge shows overhead, it's clear that there is more overhead than I really could imagine. For upstream overhead can be easily up to 25% of the traffic.

I believe there is still some minor overhead over even that figure. Because now lag is gone when I set upload to 60% of true bandwidth troughput and set deluge to substract overhead from even that rate. So data upload rate is less than 50% of total bandwidth.

I guess this case is cleared.

- Thanks

[sponix]

I'm having a similar issue. Linux Mint 19 64bit (Ubuntu 18.04 64bit based). Given I do have a lot of connections configured, and over 700 torrents seeding. BUT, I swear it was only recently that this became a problem. Going to try mirroring my connection settings and such from qBittorrent as much as possible and see if that helps, cause I have over 700 torrents seeding there with no latency issues. Right now when I fire up Deluge after a bit I get 300 to 600 MS of LAG, not just on my rig, but on my whole home network.

[Shryp]

I'm having a similar issue. Linux Mint 19 64bit (Ubuntu 18.04 64bit based). Given I do have a lot of connections configured, and over 700 torrents seeding. BUT, I swear it was only recently that this became a problem. Going to try mirroring my connection settings and such from qBittorrent as much as possible and see if that helps, cause I have over 700 torrents seeding there with no latency issues. Right now when I fire up Deluge after a bit I get 300 to 600 MS of LAG, not just on my rig, but on my whole home network.

This MIGHT be your issue.
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