Occasionally, nginx doesn't send any data back to the browser (ERR_EMPTY_RESPONSE in Chrome).
Upon checking the server error.log, I find these weird messages:
2013/10/20 23:57:40 [alert] 29146#0: *35 pread() read only 4653 of 4656 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/20 23:57:45 [alert] 29146#0: *36 pread() read only 4653 of 4656 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/20 23:58:18 [alert] 29146#0: *38 pread() read only 4650 of 4653 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/20 23:58:18 [alert] 29146#0: *39 pread() read only 4650 of 4653 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/20 23:58:19 [alert] 29146#0: *40 pread() read only 4650 of 4653 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/21 00:02:21 [alert] 29146#0: *41 pread() read only 4629 of 4641 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/21 00:02:21 [alert] 29146#0: *42 pread() read only 4629 of 4641 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/21 00:02:23 [alert] 29146#0: *43 pread() read only 4629 of 4641 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/21 00:02:31 [alert] 29146#0: *44 pread() read only 4629 of 4641 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
2013/10/21 00:02:46 [alert] 29146#0: *45 pread() read only 4629 of 4641 from "~/htdocs/index.html" while sending response to client, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", host: "localhost"
Does anyone have any idea why this happens? After a while everything is served correctly again.