Nginx 设置了 proxy cache。在请求文件时 body 被截断，但是 access 日志是 HIT。

"-" "-" - - 21.264 [time] 200 "GET /filePath&tm=300 HTTP/1.1" 41692520 "-" "Go-http-client/1.1" "-" "HIT"
"-" "-" - - 63.975 [time] 200 "GET /filePath&tm=300 HTTP/1.1" 13434629 "-" "Go-http-client/1.1" "-" "HIT"

请问会是什么原因呢？