[Web-SIG] Emulating req.write() in WSGI

Graham Dumpleton graham.dumpleton at gmail.com
Wed Jun 30 02:17:38 CEST 2010

On 30 June 2010 02:14, Aaron Fransen <aaron.fransen at gmail.com> wrote:
> Couple more things I've been able to discern.
> The first happened after I "fixed" the html code. Originally under
> mod_python, I guess I was cheating more than a little bit by sending
> <html></html> code blocks twice, once for the incremental notices, once for
> the final content. Once I changed the code to send a single properly parsed
> block, the entire document showed up as expected, however it still did not
> send any part of the html incrementally.
> Watching the line with Wireshark, all of the data was transmitted at the
> same time, so nothing was sent to the browser incrementally.
> (This is using the write() functionality, I haven't tried watching the line
> with yield yet.)

Use a variation of WSGI middleware wrapper in:


using it to 'print' returned data to Apache log and then tail Apache
error log to see when that data is output. Alternatively, change the
code there to output a time stamp against each chunk of data written
to the file recording the response content.

This will show what data is returned by WSGI application, before
mod_wsgi truncates anything greater than content length specified,
plus also show whether it is your WSGI application which is delaying
output somehow, or whether Apache output filters are doing it.


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