[TriLUG] azureus/bittorrent slowdown

[Joseph Mack NA3T]

Chris and Steve suggested stopping java from caching DNS. 
That didn't help, but thanks for the suggestion.

Aaron - yes I undestand that it's a NAT problem, but I still 
don't understand why it works at all if NAT isn't setup. 
Lance says that everything will crawl to a halt, which is 
what I see, but why it works at all I don't know.

On Wed, 19 Dec 2012, Lance A. Brown wrote:

>>> I fixed it by manually entering the port forwards needed 
>>> to allow inbound connections to my torrent program.

I had my firewall dropping all connections to high ports. I 
added an exception for 47518. In my rrdtool graphic 
monitoring, I now have almost no high port packets being 
dropped. Previously I had about 6/sec. When I wrote my 
firewall, I looked at dropped packets to see if they might 
be anything I needed. Presumably I looked at all these 
packets but I can't have seen that they were all to or from 
47518. With my machines all appearing to behave normally 
enough, I had no idea what these packets were.

Following your suggestion, I forwarded 47518 (t and u) to my 
azureus box and put in a dnat rule for tcp and udp. The nat 
test in azureus now passes.

The change was immediate. The window from which I launched 
azureus, had been a waterfall of errors, which I never 
understood

eg

Exception while processing the Tracker Request for http://tracker.bittorrent.am:80/

these stopped (or only come now and then)

In the azureus gui, now all files are either inactive or 
uploading. Previously there'd been errors for many of the 
files. Now about 16 files are uploading, whereas before only 
ever 1 or 2 files would upload.

I'm only uploading at about 75% of my set upper limit. I 
would have expected it to go at full bore. I guess there's 
more uploaders than is needed ;-)

>> let me try that.
>>
>> If it needs these, how can it work at all if I don't have 
>> them?
>
> Very poorly if at all.  Initially, while you are 
> downloading files using bittorrent, things will go well. 
> After a while, if you can't reliably get inbound 
> connections, you'll see things tail off and you won't be 
> able to seed torrents worth a damn.

downloads go fine. I guess masquerading will handle that.

However I have been uploading for years, admittedly at an 
erratic rate.

I expect to start an upload (seed?) someone has to connect 
to me. Is there a way of uploading where I connect to 
someone else?

Looking in the azureus screen I see under the "seeds" column 
for uploading file "0 of n" (n some int). I take it I'm not 
seeding.

For the inactive files I see numbers in the "seeds" column. 
I take it that these are other people seeding.

Under "peers" I see "3 of 15" which means I'm peering with 3 
hosts (at least from the swarm diagram).

Presumably when I upload I can seed or peer and I've only 
ever been peering before.

Joe

-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!