請求超時問題排查
微服務調用一個阻塞連接，需要2到3分鐘，但是每次到60秒時，後臺出現504 getway timeout問題，初步懷疑是ribbon的超時導致的，檢查發現不是，排除；再次懷疑nginx默認的60秒超時導致，發現配置了proxy-read-timeout、proxy-connection-timeout等參數依然無效，在這裏還以爲是nginx配置的不對，做了很多實驗，花了不少時間，依然無效，頁面仍然包504。
查看nginx錯誤日誌，報一下錯誤：
2020/05/28 10:38:50 [info] 27861#0: *19551718 epoll_wait() reported that client prematurely closed connection,
so upstream connection is closed too while sending request to upstream, client: xx.xx.xx.xx, server: xx.xx.xx.xx,
request: "POST /xxxm?wId=00000172-5924-9980-0019-c87063eaafe0&orgId=05ec79d926dc41d59d324eaa2807bdd4 HTTP/1.1",
upstream: "http://127.0.0.1:xx/xxxx?wId=00000172-5924-9980-0019-c87063eaafe0&orgId=05ec79d926dc41d59d324eaa2807bdd4",
host: "www.xxxx.com", referrer: "https://www.xxxx.com/"
2020/05/28 10:38:50 [info] 27862#0: *19551720 epoll_wait() reported that client prematurely closed connection,
so upstream connection is closed too while sending request to upstream, client: xx.xx.xx.xx, server: xx.xx.xx.xx,
request: "POST /xxxx HTTP/1.1", upstream: "http://127.0.0.1:xxx/aimxxxx",
host: "www.xxxx.com"
網上查詢都說是nginx超時，或者後端微服務超時，和我上面實驗的內容大同小異。
一系列搜索無效後，認真看看上面的日誌，突然靈光一閃，日誌報的是client prematurely closed connection啊，客戶端關閉了連接啊，我查後端的有什麼用呢，這時候猜測可能是阿里雲的負載均衡做了超時設置，果然發現阿里雲的負載均衡域名默認超時是60秒，果斷改掉，重新試了下，嗯？？？怎麼還不行，崩潰。重啓下負載均衡slb試試，終於好了。。。。