Assymetric pairings
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I noticed pairings between 2 competitors are being scored differently. A vs B score is different than B vs A score.
LiteRumble could stabilize twice as fast if a given battle upload is updated for both competitors involved.
Certainly looks that way. At this moment, XanderCat 12.6 has run against all other opponents, but if I go look at some of the opponents who do not have full pairings, ones that XanderCat 12.6 has run against, XanderCat 12.6 doesn't show up.
Also, a number of values are coming up 0. Will those eventually update when pairings complete, or are not all scores currently tallied (either intentionally or due to a bug)? I know there was talk of dropping ANPP, so maybe that is 0 on purpose, but Vote for XanderCat 12.6 also comes up 0, even though XanderCat 12.6 shows up against PolishedRuby, who XanderCat gets top score against.
Those complex rankings are coming up 0 because they didn't have some battles run against them after the batch rankings was run, and got evicted from cache before their new data was written to disk. I think I'll do a disk dump at the end of each batch processing job, see if that sorts this out.
A lot of these problems are showing up because I put a bit too much 'eventually' into the 'eventually consistent' model.
They are both updated at the same time, but for a long time I had very aggressive caching on to keep within the free tier. Because App Engine Memcache can be cleared without warning, this meant that often one bot would lose a battle before it could be written to disk, but not the other. Ironically, this is one of those situations where a higher client load on the server means that less data gets lost, since the bot was more likely to hit the 'write threshold' before being evicted from the cache. Now that I have more writes to play with, I've lowered the write caching thresholds a lot, and we should eventually see everything settling down.
One big cache for everything. I used to have a queue for each rumble that would fill up, and each time a bot had over X battles it would be written to the database. Of course, when the nanorumble only gets 1/10th or less the battles of the main rumble, the bots in it are more likely to be evicted, resulting in incomplete and asymmetric pairings. So I've just rewritten that section to keep just two queues (only split between 1v1 and melee), and bots are written as a batch as soon as the queue is a certain size. That way, even bots getting less battles will still be written because they are all pushing each other through, so it should stabilize better. Unfortunately I couldn't do this before because I was too limited with writes.
What is the queue size?
