doubt with proxy busy buffer

[Maxim Dounin]

Hello!

On Thu, Sep 01, 2011 at 03:30:34AM -0400, bigplum wrote:

> Hi,
> 
> I write a module for file download, but sometimes it will alert 
> "the http output chain is empty while sending to client".
> And I check the code, it seems that if proxy busy buffer run out,
> write_filter will always return ngx error.
> 
> Is that right? 

If ngx_http_write_filter() is called with NULL, r->out must not be 
empty.  If it's empty - this means that buffer(s) to flush 
disappeared somewhere, and alert will warn you about this problem.

Maxim Dounin