Pub/sub for detecting data modification

[ghost]

Currently, the database is completely reloaded every Intervals.DatabaseReload seconds. This is obviously very inefficient, as well as potentially dangerous, but at the time it was written it needed to be compatible with the existing tracker software that was in use.

The way data changes should be handled is with a publish/subscribe architecture. My plan is to use redis for this. There will need to be a "deleted" channel and a "modified/new" channel.

I'm not sure if it'd be better to pass in just the modified IDs and have the tracker hit the database, or if it'd be better to pass the entire object over redis.

[jzelinskie]

Another thing to keep in mind is that postgres supports a pub/sub feature. There's a performance comparison here:
https://gist.github.com/fcurella/3490031
It looks like you get similar performance without the added resource cost of running redis.

[ghost]

redis is going to be used by Batter anyways, so it's a moot point.

[jzelinskie]

The new architecture expects that a third party is updating the data store when information like this changes. The role of a torrent tracker is to simply read from the data store and update existing values. It shouldn't be the tracker's job to attempt to synchronize with changes in other programs.