Question about Connection: close and proxy_pass

[Steve Smith]

BTW, here's my comments on the WANdisco support ticket:

   Here's the sequence of events:

   * Client initiates a request to nginx
   * Nginx initiates a request to WANdisco with "Connection: close"
   * WANdisco passes this through to Apache/SVN
   * Apache returns data with "Connection: close" and closes the
     connection as originally requested
   * WANdisco returns the data but does not close the connection
   * Connection hangs as nginx is waiting for the close

   My take on this is that WANdisco should be closing the
   connection. Either WANdisco is acting as a true server, in which case
   it should honour the "Connection: close", or it is acting in a
   transparent manner, in which case it should pass on the change of
   state (i.e. close) from Apache to nginx.  However the HTTP1.0 spec is
   vague on this.

However as Igor pointed out both sides seem to be at fault; nginx
should probably be closing the connection if it can given it has
received a close header.

Cheers,
Steve

On Fri, Sep 5, 2008 at 1:24 PM, Steve Smith <tarkasteve at gmail.com> wrote:
> Hi,
>
> Unfortunately the WANdisco upgrade didn't help, I'm still seeing the
> same behavior.  It would be nice to have a nginx fix; I'm now using
> pound to front this system.
>
> Cheers,
> Steve
>
> On Thu, Sep 4, 2008 at 4:56 PM, Steve Smith <tarkasteve at gmail.com> wrote:
>> Hi,
>>
>> WANdisco have owned up to the close issue from their end, the latest
>> version apparently has a fix, although I haven't managed to try it
>> yet.
>>
>> Cheers,
>> Steve
>>
>> On Thu, Sep 4, 2008 at 3:57 PM, Igor Sysoev <is at rambler-co.ru> wrote:
>>> On Wed, Sep 03, 2008 at 10:58:25PM -0400, Dave Cheney wrote:
>>>
>>>> We're using nginx to proxy between a piece of software that doesn't
>>>> understand our SSL certificate. The diagram looks like this
>>>>
>>>> client --> port:443 --> nginx --> port:8181 --> WANDisco
>>>>
>>>> What we are seeing is nginx is forwarding the request to WANDisco on port
>>>> 8181 with a Connection: close header (as expected). The response is coming
>>>> back from WANDisco with a Connection: close header also, see below for the
>>>> abridged version
>>>>
>>>> nginx -> wandisco
>>>> GET /svn/private/ HTTP/1.0
>>>> Host: 127.0.0.1:8181
>>>> Connection: close
>>>> User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.1)
>>>> Gecko/2008072820 Firefox/3.0.1
>>>>
>>>> wandisco -> nginx
>>>> HTTP/1.1 200 OK
>>>> Date: Thu, 04 Sep 2008 02:14:05 GMT
>>>> Server: Apache/2.2.9 (Debian) DAV/2 SVN/1.4.2 mod_ssl/2.2.9 OpenSSL/0.9.8g
>>>> mod_perl/2.0.4 Perl/v5.10.0
>>>> Last-Modified: Thu, 04 Sep 2008 01:46:09 GMT
>>>> ETag: W/"66230//"
>>>> Accept-Ranges: bytes
>>>> Content-Length: 439
>>>> Connection: close
>>>> Content-Type: text/html; charset=UTF-8
>>>>
>>>> [body skipped]
>>>>
>>>> So the response has a content length and Connection: close. However nginx
>>>> does not consider the response 'done', until wandisco has closed its side
>>>> of the socket.
>>>>
>>>> My reading of RFC 2616 is unclear. Section 14.10
>>>> (http://tools.ietf.org/html/rfc2616#section-14.10) says
>>>>
>>>> "HTTP/1.1 defines the "close" connection option for the sender to
>>>>    signal that the connection will be closed after completion of the
>>>>    response. For example"
>>>>
>>>> Which appears to indicate that the sender will close the connection, but
>>>> does not use RFC 2119 grammer to indicate that it must.
>>>>
>>>> My question is, is this a bug? Should nginx close its side of the
>>>> connection onces it has read Content-Length: bytes, or should WANDisco
>>>> close its side after sending the response.
>>>
>>> I think these are bugs on both side:
>>> 1) nginx should send response after it gets CL bytes,
>>> 2) while WANDisco should close a connection after it has sent whole response,
>>>   if it has said that "Connection: close".
>>>
>>>
>>> --
>>> Igor Sysoev
>>> http://sysoev.ru/en/
>>>
>>>
>>
>