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Slow queries in replay endpoints

オープン
  • 何か問題がありますか？
#1,182 コメント 3 件 リアクション 0 件 担当者 0 名 GitHub で見る

まだ誰も着手していません。

評価

難易度
4/5
見積もり時間
3〜5日
初心者へのやさしさ
48/100
issue の種類
バグ
明瞭さ
おおむね明確
活発さ
活発
技術スタック
java, spring, sql
領域
backend-api-design, databases

調査の方向性

Start with Game.java and the referenced V107__baseline_schema.sql indexes, then inspect later migrations in FAForever/db and the query plan for the map-filtered, newest-first /data/game request. Check whether the proposed composite index is appropriate for this query and how Elide uses it. Done means the change is measured against the reported slow search and its impact on other queries is considered.

索引モデルが issue の本文から書いたものです。

説明

Searching games by map is slow for popular maps

Searching /data/game with a filter on the map name takes up to 20 seconds when the map is popular. The same search without the sort, or with a player filter added, answers in under 0.2 s. Claude says this may be because of a missing index. This would be a small change, but I can't oversee the exact implications myself. Essentially this is suggested:

A composite index in FAForever/db:

CREATE INDEX game_stats_mapId_startTime ON game_stats (mapId, startTime);

I've always noticed that the replay tab can be quite slow, this has been happening for years. I only make this ticket because I noticed that it may be a small fix. But I don't know how Elide interacts with an additional index. If I am totally off based on your gut, then feel free to close this immediately.

The query

The web vault (https://vault.jipwijnia.nl) searches games like this, 12 per page, newest first:

GET /data/game
  ?include=playerStats,playerStats.player,mapVersion,mapVersion.map,featuredMod
  &sort=-startTime
  &page[size]=12&page[number]=7
  &page[totals]
  &filter=endTime=isnull=false;mapVersion.map.displayName=="*Seton*"
Measurements

Measured on 2026-10-06 from a browser, with a bearer token. The API caches answers per URL (repeating a URL returns in about 55 ms), so each search was run three times with a different page (7, 8 and 9) to make every call uncached. The three runs were within 2% of each other.

Search (all with endTime=isnull=false) Matching games Time
No other filter 19.2 million 1.25 s
No other filter, no page[totals] 0.08 s
Player (a player with about 5,000 games) 5,087 0.22 s
Map *Seton* 1.35 million 20.8 s
Map *Seton*, no page[totals] 19.1 s
Map *Seton*, no page[totals], no include 19.0 s
Map *Seton*, no page[totals], no sort 0.09 s
Map "Seton's Clutch" (exact), no page[totals] 14.8 s
Map *Fields of Isis*, no page[totals] 4.6 s
Map *Theta Passage*, no page[totals] 1.1 s
Player and map *Seton* 834 0.14 s

The moment I search for a map with many replays + sorting the endpoint time explodes.

Suspected cause

Game maps to game_stats and reaches the map through mapId → map_version → map. In the schema, game_stats has separate indexes on mapId and on startTime (twice: startTime and game_stats_startTime_index), but none on both together. No later migration adds one.

So for "the newest 12 games on this map" the database has to either collect all games of the map's versions through mapId and sort them (1.35 million rows for Seton), or walk all games backwards through startTime and check the map of each. Both fit the timings above: fast without the sort, slower the more the map is played.

主要言語
Java
スター
31
フォーク
30
30日以内にマージされた PR はありません

環境構築

  • Dockerfile または Docker Compose ファイルあり
  • プルリクエストのテンプレートなし
  • コントリビューションガイドなし

はじめの一歩

  1. issue を最後まで読み、次にプロジェクトのコントリビューションガイドを読みます。
  2. 着手することを issue にコメントします — 二人が同じ作業をするのを防げます。
  3. リポジトリをフォークし、ブランチを切って変更します。
  4. issue 番号を参照したプルリクエストを送ります。

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