I use nginx 0.6.31 with proxy_pass to front end requests to a servlet
running in Jetty (the upstream).
Sometimes I need to update a jar on the upstream, which requires
restarting jetty to take effect.
I am looking for a way to tell nginx that if it gets a connection
failure at the upstream (which is what happens when jetty is in the
process of restarting since nothing is listening on that port during the
restart) that it should give it say 20 seconds before erroring out the
request back to the browser.
Certainly this will back up the processing a bit, but it should be very
short as it only takes Jetty about 10 seconds to restart and start
listening again on its port. During slow periods we are only getting 2-5
requests per second so there should be plenty of resources for nginx to
queue up these requests while it waits for Jetty.
Can someone please tell me what settings I should use so that nginx will
wait up to 20 seconds for the upstream to restart so that it doesn’t
return an error to the browser?
In the past I have tried setting all these to 20 seconds:
but when I restarted Jetty, right away the nginx error logs started
showing errors like:
[error] 6445#0: *141102686 connect() failed (111: Connection refused)
while connecting to upstream
Are the above configuration parameters correct for what I am trying to
do and maybe I just didn’t set them right? Or is there some other way?
Basically what I’m trying to do is set those settings high, tell nginx
to reload its config, then bounce jetty, then have nginx hold the
requests long enough to get through once jetty is back up and then have
the requests go through to jetty without losing any requests. Then after
jetty is restarted I would put the timeouts back to normal levels like
3s, until the next time I have to do an update.
Either that or if I could send nginx a signal that told it to accept
incoming connections but put them on “pause”, then i can restart jetty
and then unpause nginx once jetty is back up without dropping any
Hopefully I explained this well what I am after. Please let me know your
thoughts on the best way to do this.