搜索廣告系統簡單架構
Query Analysis:
糾錯、同義變換、改寫
切詞、提取主題詞
意圖分析
User Server:
Demographic
Cookie
Session
Board match server:
實現寬泛匹配
寬泛匹配的相關性很重要
e.g. Query Rewriting:
rewrite user query q into Q' = (q1,q2,q3,...)
Use EM to select ads for Q'
Fits well in the current system architectures
Index Server:
實現精確匹配、短語匹配
各種業務過濾功能
查找廣告倒排索引
Ad Server:
正排表查找廣告物料：創意標題、描述、URL
CTR Server:
實現CTR預估功能
計算密集，內存密集
Auction Server:
廣告排序:Q*Bid
廣告計價 Price = Q'*Bid'/Q