"DhtServer::event_write called but both write queues are empty" Error

[HarryMuscle]

Running your version of rTorrent 0.9.8/0.13.8 I regularly get the following error:

C Caught internal_error: 'DhtServer::event_write called but both write queues are empty.'.

This seems to be a known issue and is discussed further in the following issues from other rTorrent repo's and related projects:

rakshasa/libtorrent#141
rakshasa/rtorrent#760
chros73/rtorrent-ps-ch#166

Also included in those issues are logs and a possible workaround patch. Unfortunately it looks like this issue is not being acted on since it's been known for years. I was wondering if you would consider adding the workaround patch or maybe a different solution to your version of rTorrent so that this issue can be fixed.

[jesec]

DHT-related codes are s***hole. They haven't been updated for almost a decade, and there is minimal activity on them after initial addition. When the number of DHT-enabled torrents (and, as a result, DHT peers) is sufficiently large, they are prone to overflow and other issues. There is also a race condition. Performance issues are prevalent as well.

At best, they could lead to some stability issues. At worst, it could be possible for one to find a way to exploit those issues.

I deployed sanitizers and other technologies to spot obvious issues. Some issues are fixed, but for others, only band aids are applied.

I plan to clean up this DHT mess when I get the chance. However, I am not a frequent user of DHT myself, and I keep DHT disabled on my rTorrent instance. I would recommend users to do the same when they don't need DHT.