[PATCH 1 of 1] Test proxy_unfinished: limit buffers to force buffering on no proxy temp

[Markus Linnala]

On 15.04.2014 16:04, Maxim Dounin wrote:
> Hello!
>
> On Tue, Apr 15, 2014 at 03:26:26PM +0300, Markus Linnala wrote:
>
>> # HG changeset patch
>> # User Markus Linnala <Markus.Linnala at cybercom.com>
>> # Date 1397505734 -10800
>> #      Mon Apr 14 23:02:14 2014 +0300
>> # Node ID cf54213675d59b801bee34328223c28f992cf8c7
>> # Parent  74a015aad3521ffef6b404cdaa9eafd991824301
>> Test proxy_unfinished: limit buffers to force buffering on no proxy temp
>>
>> With some systems (Fedora-20 Linux 3.13) socket buffers are huge and
>> nginx does not use temp files when proxying. Set buffer sizes to small
>> values to make use of temp files more probable. Currently there is no
>> way to force temp buffers.
>>
>> no proxy temp should fail on 1.5.2 and work okay on later versions.
>>
>> sub_filter forces chunked encoding and so it is possible to notice
>> problem because last chunk is 0 chunk when there is error.
>>
>> Only use limited buffers on 'no proxy temp' as other tests fail
>> because tests take too long.
>>
>> http://trac.nginx.org/nginx/ticket/541
>
> [...]
>
> Have you tried something simplier, like
>
> --- a/proxy_unfinished.t
> +++ b/proxy_unfinished.t
> @@ -50,7 +50,7 @@ http {
>                          keys_zone=one:1m;
>
>       server {
> -        listen       127.0.0.1:8080;
> +        listen       127.0.0.1:8080 sndbuf=4k;
>           server_name  localhost;
>
>           location / {
>
>
> ?
>

I did not try plain 4k.

I did try smaller buffers and 'big (un)?finished un' tests were 
failing because it took too longer than 5s to do test. Now I ran 
tests again and if sndbuf is less than 4k or maybe some buffer size 
you get really bad throughoutput.

not ok 13 - big unfinished un

#   Failed test 'big unfinished un'
#   at proxy_unfinished.t line 152.
#                   undef
#     doesn't match '(?^s:unfinished)'
not ok 14 - big finished un

#   Failed test 'big finished un'
#   at proxy_unfinished.t line 153.
#                   undef
#     doesn't match '(?^s:finished)'


If sndbuf is more than about 36k test seems to fail sometimes.

One way to force creating of temp_file is to use proxy_store, but 
then test does not work as it does not start to response before 
there is error.

With my patch nginx tries to create temp-file when it has sent out 
24k of a response. With sndbuf=4k it tries to create temp file 
around 90k. I see this by running prove under strace.

strace -ff -o foo -s 200 -tt prove

Extra sleep 0.5s or lowering proxy buffers size does not seem to 
affect the no proxy temp test.

-- 
Markus Linnala, Chief Systems Architect
Cybercom Finland
Pakkahuoneenaukio 2 A; 33100 Tampere
Mobile +358 40 5919 735
Markus.Linnala at cybercom.com

www.cybercom.fi | www.cybercom.com