求助 upstream timed out (10060: A connection attempt failed because the connected party did not properly respond

在发起 curl 请求之后，nginx 就爆这个错误，折腾了一早上了，无果，求助

upstream timed out (10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond) while reading response header from upstream, client: 127.0.0.1, server: xxx.cc, request: "GET /xxx/y HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "xxx.cc"