Torrenting problems

[chimney sweep 1]

I am experiencing problems with torrent sharing and downloading.
I noticed that since I have a large download (over 50GB) that took a while to find in the first place. 
Before, I used to download TV series etc. that very often have many peers and I didn't notice any issues.

First off, I notice that using different AirVPN servers, the number of peers that the torrent client fiends is very different. 
I am using Transmission on Mac OS.
Then I noticed that while the torrent client finds peer that have up to 100% of the torrent files, very often the download connection drops out (it downloads for a while, then drops to 0 for a while).
The torrent client also lost connection to peers very often. The peers would disappear from the list then re-appear shortly after.

I then set the port for torrenting to one that was forwarded. That hadn't been the case previously.
I confirmed that the port is indeed open.
I also tried 3 servers that according to the servers list on airvpn.org have great performance.

Here it starts to get puzzling. What I saw with the 3 servers (1 Asellus, 2 Gianfar, 3 Ophiucus) that I hadn't used before was that when launching the torrent client, I immediately had more peers and immediately had constant fast downloads for that one big download.
However, after a while, the downloads dropped to 0 on the big torrent download.
On the 2nd server that I tried, (Gianfar) all downloads and all uploads dropped to 0. I waited 10-20 minutes but everything stayed at 0.
So I checked internet speed (with VPN on). Result: Very solid DL/UL speeds. No connection problems. I also had no problems browsing websites and streaming video.
I also paused and restarted the 50GB torrent download. No change.
Then I closed and restarted the torrent client (Transmission). No Change.

I connected to Ophiucus.
Result: I immediately had more peers than I have yet seen for that particular torrent (8 instead of 1 - 3) and immediately had 2 Megabye per second download speed.
After 10-20 minutes, I saw that the download speed dropped to 0 very often for 1 second intervals and then resumed at high speed.
But then the speed also dropped to 0 for 30 seconds, then high speed for 2 - 5 seconds, then 0 again...
I just watched it for 1 - 2 minutes. Good average download speeds currently, highly volatile, sometimes dropping to 0 for all peers at the same time but only shortly (1 second or less).
After typing the last sentence, I checked again: Now all torrents are at 0, DL and UL.
I am seeding several hundred torrents. Permanently 0 upload activity is not expected at any time.
The torrent client still has connections to all the peers but no DL/UL.

One peculiar thing I do notice:
While most of the time everything is at 0 at the moment, there is periodically DL/UL activity at solid speeds for less then one second at a time, then falling back to 0. 


Any information how to fix this would be appreciated.

 

[OpenSourcerer 1360]

I remember something like that, but on Windows… what are your connection settings in Transmission?

[chimney sweep 1]

 

bandwidth:

unlimited DL/UL

 

max connections to peers:

was 1500, now set to 1000

 

max connections for new transmissions:

was 1000, now set to 500

 

(on) exchange PEX data for public torrents

(on) use distributed hash table (DHT)

 

(on) prefer peers with encrypted connections

(off) ignore peers with unencrypted connections

 

network:

(on) use Micro Transport Protocol (µTP)

port 62834

(off) choose port randomly

(off) auto port forwarding via router (NAT-PMP, IPnP)

 

(on) prevent sleep while there are active transmissions



I'd like to add that I looked at the CPU use. I suspected that some process might have occupied a lot of the CPU resources thus stopping other applications. I didn't see anything of that sort. CPU use is rarely more than 20%.
 

[OpenSourcerer 1360]

20 minutes ago, chimney sweep said:

(on) use Micro Transport Protocol (µTP)

This one's a candidate, it's got a history on these forums. Turn this off. It's a bandwidth management protocol that rarely plays nicely with UDP-based VPN connections.

[chimney sweep 1]

19 minutes ago, OpenSourcerer said:

This one's a candidate, it's got a history on these forums. Turn this off. It's a bandwidth management protocol that rarely plays nicely with UDP-based VPN connections.

I have just been reading about what this µTP is after my last post. I was contemplating switching it off.

What I changed was the port. It was the default port in Transmission. I changed it. I added the new port in the AirVPN user area and checked that the port is open. 
Result: Same. 

Switching off µTP now. Lets see if that helps.
 

[chimney sweep 1]

The dropouts seem to still happen with µTP switched off. 
I closed and re opened the torrent client.
Tried 2 more AirVPN servers.
 

[feuxeu77 0]

Hi

I am experiencing similar issue since yesterday. Low number of seeds and, more important, very low speed per seed (like 10kB/s).

Did you find any solution ? I tried multiple servers, changing the port, uTP, .... no impact. I am using Transmission too.

Edit:  Actually, must be something else. I have the exact same issue without going through the VPN

Edited ... by feuxeu77
Found a new clue

[OpenSourcerer 1360]

48 minutes ago, feuxeu77 said:

Hi

I am experiencing similar issue since yesterday. Low number of seeds and, more important, very low speed per seed (like 10kB/s).

Did you find any solution ? I tried multiple servers, changing the port, uTP, .... no impact. I am using Transmission too.

Edit:  Actually, must be something else. I have the exact same issue without going through the VPN 

Open your own thread. As you can see, you've got a low number of seeds and very low throughput; these two alone should tell you your issue is very different.
 

20 hours ago, chimney sweep said:

The dropouts seem to still happen with µTP switched off. 

That's too bad. Try lowering the number of connections, or change the settings according to the Azureus calculator. You can ignore the "Max active torrents" value and all comments about Azureus there.

I'm looking for ways to troubleshoot this further, but you're on macOS which is not exactly my expertise. Maybe others can chime in, too.

[chimney sweep 1]

On 11/27/2021 at 2:17 PM, OpenSourcerer said:

That's too bad. Try lowering the number of connections, or change the settings according to the Azureus calculator. You can ignore the "Max active torrents" value and all comments about Azureus there.

It looks to me like it is a problem with the hard drive read/write bandwidth.
I have everything on an encrypted disk image. 
Since I had the OS crash a few days ago while the disk image was mounted, I have problems when I watch a video file that is on that disk image while the torrent client is running.
That didn't happen before.
The disk image might be damaged.
Setting it up fresh from the backup will take a couple of days.

Thank you for your suggestions and links so far.
 

[OpenSourcerer 1360]

4 minutes ago, chimney sweep said:

Since I had the OS crash a few days ago while the disk image was mounted, I have problems when I watch a video file that is on that disk image while the torrent client is running.

That is a very valuable piece of info. Have you tried checking the SMART status of your drive?

[chimney sweep 1]

3 minutes ago, OpenSourcerer said:

That is a very valuable piece of info. Have you tried checking the SMART status of your drive?

That does not work on a disk image. If you refer to the physical drive where the disk image is on, I could see if I can read that in Mac OS. It is an external USB drive. Not sure if reading SMART status is possible (on Mac OS).

Mac OS has a utility application for checking hard drives and volumes. I could check wether this can be done on a disk image. Perhaps.
However, even if there are no problems found, there might still be a problem. 
I might as well delete it an copy back from the backup.
Thank you for the tip though. It could potentially save time.

[OpenSourcerer 1360]

48 minutes ago, chimney sweep said:

Not sure if reading SMART status is possible (on Mac OS).

Seems to be possible. But if not, Homebrew -> smartmontools. With that installed, smartctl --scan prints your drives, and smartctl -a [drive] prints all SMART info on a drive. Choose the drive where it's on.

[chimney sweep 1]

Actually, I've now been minimising and monitoring read/write load and it looks like that isn't the problem, either.
Transmissions keep pausing.
Again, I did notice that the number of peers that the torrent client sees can vary a lot depending on which AirVPN server I am connected to.

I paused seeding a lot of torrents and reduced the number of connections and bandwidth allowed. Nothing helped so far. today