2011年3月9日星期三

Re: [PATCH] ngx_upstream do not cleanup file buffers in subrequest

Maxim Dounin Wrote:
-------------------------------------------------------
> Hello!
>
> On Tue, Mar 08, 2011 at 03:24:47PM -0500, magz
> wrote:
>
> > Hello,
> >
> > Is it reasonable to add following check to not
> clean/discard fd in case
> > if it's sub request?
> >
> > I developed nginx module and when it started to
> use tmp buffers under
> > load I had following error:
> >
> > 29663#0: *45789 sendfile() failed (9: Bad file
> descriptor) while
> > sending request to upstream, client: 10.1.24.14,
> server: hss, request:
> > "POST
> >
> > So that sub-request cleared file before main
> request reached it.
> > Probably this bug should not appear if request
> body was discarded for
> > sub request. But in case if you need request
> body for sub-request you
> > should be sure that sub-request does not erases
> main request buffers.
>
> In official nginx, subrequests can't appear before
> main
> request.
>
> On the other hand, main request may clear body as
> well, and it
> won't be available for subrequests as a result.
> This problem may
> be easily seen with ssi module. The other
> possible case when this
> problem may appear is filter finalization (e.g. as
> done by image
> filter module).
>
> That is, just disabling body cleanup for
> subrequests is clearly
> not enough.
>
> I've already posted the patch which removes the
> code in question
> at all (as a reply to some real problems seen with
> ssi and POSTs,
> somewhere in russian mailing list). Probably it
> should be made
> controllable via some configuration directive if
> there are some
> real use cases which may be seriously affected by
> removing this
> code. I would like to hear something from Igor
> about this.
>
> BTW, just for history: the code in question was
> introduced in
> nginx 0.3.3 with the following log message:
>
> *) Bugfix: a temporary file with client
> request body now is removed
> just after the response header was
> transferred to a client.
>
> Maxim Dounin
>

additional flag to ngx_http_subrequest() has to work for this issue.


>
> >
> >
> > -- src/http/ngx_http_upstream.c_orig 2011-03-08
> 08:01:20.000000000
> > -0800
> > +++ src/http/ngx_http_upstream.c 2011-03-08
> 08:01:41.000000000 -0800
> > @@ -2033,7 +2033,7 @@
> ngx_http_upstream_send_response(ngx_http
> >
> > u->header_sent = 1;
> >
> > - if (r->request_body &&
> r->request_body->temp_file) {
> > + if (r->request_body &&
> r->request_body->temp_file && r == r->main)
> > {
> > ngx_pool_run_cleanup_file(r->pool,
> > r->request_body->temp_file->file.fd);
> > r->request_body->temp_file->file.fd =
> NGX_INVALID_FILE;
> > }
> >
> > Posted at Nginx Forum:
> http://forum.nginx.org/read.php?2,181400,181400#ms
> g-181400
> >
> >
> > _______________________________________________
> > nginx mailing list
> > nginx@nginx.org
> > http://nginx.org/mailman/listinfo/nginx
>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://nginx.org/mailman/listinfo/nginx

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,181400,181710#msg-181710


_______________________________________________
nginx mailing list
nginx@nginx.org
http://nginx.org/mailman/listinfo/nginx

没有评论:

发表评论