nginx問題排查: upstream prematurely closed connection while reading response header from upstream

問題背景 我們這邊是一個基於Nginx的API網關（以下標記爲A），最近兩天有調用方反饋，偶爾會出現502錯誤，我們從Nginx的error日誌裏看，就會發現有" upstream prematurely closed connection while reading response header from upstream"這麼一條錯誤日誌，翻譯過來其實就是上游服務過早的關閉了連接，意思很清楚

>>阅读原文<<