Gzip gzip_min_length directives doesn't work in ajax?

I have the following conf

http {

gzip on;
gzip_min_length 1000;
gzip_buffers 16 64k;
gzip_http_version 1.1;
gzip_comp_level 6;
gzip_types text/plain application/x-javascript text/css
application/xml;
gzip_vary on;

I notice that the gzip_min_length 1000; dirctives doesn’t word in ajax.

the request header:

Host 10.66.23.99
Accept-Charset GB2312,utf-8;q=0.7,;q=0.7
(Request-Line) GET /luapp/getname?query=dsfds HTTP/1.1
Accept-Encoding gzip, deflate
Connection keep-alive
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20100101
Firefox/5.0
Cookie name=bq0xPMS+HUgGYuV7pB9f9j6l9qhcIdS3fABQDOlgsuY=;
returnurl=/app/images/shadow.png
Accept text/html,application/xhtml+xml,application/xml;q=0.9,
/*;q=0.8
Accept-Language zh-cn,zh;q=0.5

the response header:
(Status-Line) HTTP/1.1 200 OK
Connection keep-alive
Content-Encoding gzip
Content-Type text/html; charset=UTF-8
Date Sun, 24 Jun 2012 08:37:05 GMT
Server ngx_openresty/1.2.1.1
Transfer-Encoding chunked
Vary Accept-Encoding

the url:http://10.66.23.99/luapp/getname?query=dsfds
the return content:
{“query”:“dsfds”,“suggestions”:{}}
the size of return content is 35bytes,is smaller than gzip_min_length
in the conf,but it is still gziped,
the gzip resut:text/html; charset=UTF-8 : 35 bytes, gzip compressed to
55 bytes ( -57.1 % saving )

Why?
I’m using nginx 1.2.1

Hello!

On Sun, Jun 24, 2012 at 04:54:28PM +0800, lhmwzy wrote:

gzip_vary on;

Connection keep-alive
Content-Encoding gzip
in the conf,but it is still gziped,
the gzip resut:text/html; charset=UTF-8 : 35 bytes, gzip compressed to
55 bytes ( -57.1 % saving )

Why?
I’m using nginx 1.2.1

The gzip_min_length directive doesn’t work if length isn’t known.

Maxim D.