What does the below warn message mean?

[warn] 14606#0 : *1114899 an upstream response is buffered to a temporary file /opt/zimbra/nginx-0.5.30-zimbra/proxy_temp/1/20/0000002201 while reading upstream, client: xx.xx.xx.xx, server: web2.domain.com, URL: "/service/zimlet/res/Zimlets-nodev_all.js.zgz?language=en", upstream: "http://10.10.x.x:80/service/zimlet/res/Zimlets-nodev_all.js.zgz?language=en", host: "webmail.domain.com",
referrer: "http://webmail.domain.com/zimbra/"

[info] 14606#0: *1114655 client xx.xx.207.66 closed keepalive connection (104: Connection reset by peer)

anticipating your helps.Thanks in advance
G'day!