Recompute mutual-follow bits on cached For You posts - #57
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Recompute mutual-follow bits on cached For You posts#57Pitchfork-and-Torch wants to merge 19 commits into
Pitchfork-and-Torch wants to merge 19 commits into
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in_network_ids is passed to the VF client without deduplication, while oon_ids is deduped four lines below. retweeted_tweet_id is pushed for every candidate that has one, so the same ID repeats once per retweet of a given post — most often when that post is going viral. Neither VfClient implementation dedupes its input: StratoVfClient builds one call per element, and XaiVfClient chunks by XAI_VF_MAX_BATCH_SIZE, so duplicates consume batch slots and can force an extra round trip. Not a correctness issue — results collapse into a HashMap keyed by tweet ID — but redundant work on the For You serving path. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Deduplicate in_network_ids before VF lookup
BidirectionalFollowHydrator skipped cache hits, so RankingScorer kept applying the default +15 reply-head boost from a stale is_mutual_follow_author bit for up to 180s. Co-authored-by: Jon Bailey <Pitchfork-and-Torch@users.noreply.github.com>
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Bug
BidirectionalFollowHydrator.enablewasflag && !has_cached_posts.FollowedUserIdsQueryHydratorstill runs on a cache hit. The follow list is current.RankingScorerstill runs. It readsis_mutual_follow_authorand, when that bit isSome(true), addsBidirectionalFollowReplyWeightBoostto the reply head. That boost defaults to 15.0 on aReplyWeightof 5.0.Skipping the hydrator keeps the bit written up to 180s earlier. A new mutual does not get the boost. A broken mutual keeps a 4x reply-head weight.
PhoenixScoreris also skipped on the cache hit, so the weighted score is rebuilt from cached phoenix heads times the stale bit.CachedPostsQueryHydratorsetshas_cached_postswhen Redis returns at least 500 posts. TTL is 180s.This is not xai-org#135 (
in_networkbit). Not xai-org#156 (block / nsfw_author / quote).Five-line proof
BidirectionalFollowHydrator(enableskippedhas_cached_posts)RankingScorer::reply_weight_for/dwell_weight_for(is_mutual_follow_author == Some(true))in_networkon the same cache hit; Rehydrate block and author-label bits on cached For You posts xai-org/x-algorithm#156 recomputes block / nsfw bitsFix
Enable whenever the hydration flag is on.
updateoverwrites the cached bits.Tests
enableis true on cache hit and missSome(false)Some(false)Some(true)RankingScorertestbidirectional_weight_boosts_only_mutual_original_postsis the score sink.cargo testcannot run here. Public dump has no Home Mixer manifest.