Output buffering issues with nginx, php5-fpm and EventSource

[bantu]

I am using ownCloud on php5-fpm via nginx.

When downloading files via link, the EventSource class is used to communicate with the JavaScript EventSource client which in turn updates the user visible progress bar. Albeit EventSource::send() performs a call to flush(), the data never makes it to the browser before the file is completely downloaded.

This is because nginx buffers the body for various reasons (this is usually the default behaviour). For example when gzip is on, the response has to be buffered in order to get the content-length header right.

The manual at http://nginx.org/en/docs/http/ngx_http_fastcgi_module.html#fastcgi_buffering suggests that header('X-Accel-Buffering: no') could be used to disable buffering when necessary (which is desirable), but the option is not available before version 1.5.6.

Furthermore, I can sofar confirm that using "fastcgi_keep_conn on;" in the nginx config also fixes the issue, although I am not 100% sure why.

[jancborchardt]

If you already have a possible solution, can you just submit a pull request? Thanks