joewiz

On Tue Oct 27, 2015, history.state.gov began buckling under load, intermittently issuing 500 errors. Nginx's error log was sprinkled with the following errors:

2015/10/27 21:48:36 [crit] 2475#0: accept4() failed (24: Too many open files)

2015/10/27 21:48:36 [alert] 2475#0: *7163915 socket() failed (24: Too many open files) while connecting to upstream...

An article at http://www.cyberciti.biz/faq/linux-unix-nginx-too-many-open-files/ provided directions that mostly worked. Below are the steps we followed. The steps that diverged from the article's directions are marked with an *.

1. * Instead of using su to run ulimit on the nginx account, use ps aux | grep nginx to locate nginx's process IDs. Then query each process's file handle limits using cat /proc/pid/limits (where pid is the process id retrieved from ps). (Note: sudo may be necessary on your system for the cat command here, depending on your system.)
2. Added fs.file-max = 70000 to /etc/sysctl.conf

tomcatzh

func NewGzipReader(source io.Reader) io.Reader {
	r, w := io.Pipe()
	go func() {
		defer w.Close()

		zip, err := gzip.NewWriterLevel(w, gzip.BestSpeed)
		defer zip.Close()
		if err != nil {
			w.CloseWithError(err)
		}