I run a wordpress site. when i visit the pages is so slow.
In the nginx errors logs.

[notice] 5164#3596: signal process started
[notice] 5720#7144: signal process started
[notice] 5248#6612: signal process started
[notice] 5312#1340: signal process started
[error] 6268#5220: *68 WSARecv() failed (10054: FormatMessage() error:(15100)) while reading response header from upstream, client: 127.0.0.1, server: wp_watawebu.app, request: "POST /wp-admin/admin-ajax.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9001", host: "wp_watawebu.app:8080", referrer: "http://wp_watawebu.app:8080/wp-admin/post.php?post=9&action=edit"
[error] 6268#5220: *21 WSARecv() failed (10054: FormatMessage() error:(15105)) while reading response header from upstream, client: 127.0.0.1, server: wp_watawebu.app, request: "GET /?ver=19042017104908 HTTP/1.1", upstream: "fastcgi://127.0.0.1:9001", host: "wp_watawebu.app:8080", referrer: "http://wp_watawebu.app:8080/wp-admin/post.php?post=9&action=edit"
[notice] 5944#2428: signal process started
[notice] 6156#4188: signal process started
[notice] 6288#5068: signal process started
[notice] 3452#6756: signal process started
[notice] 1460#5312: signal process started