# Content-length Missing when response proxy\_pass a special backend **URL:** \ **Category:** NGINX\ **Created:** [October 9, 2011, 4:27pm UTC](https://www.ruby-forum.com/t/content-length-missing-when-response-proxy-pass-a-special-backend/212650 "2011-10-09T16:27:07Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [October 9, 2011, 4:27pm UTC](https://www.ruby-forum.com/t/content-length-missing-when-response-proxy-pass-a-special-backend/212650/1 "2011-10-09T16:27:07Z")
I have 2 backends in my applications.There are pure backend response example: First backend: kwfs yangqingchang@yqc:~$ curl -X GET -I [http://192.168.1.118:8080/kwfs/AAChTwAAADcAAwAc](http://192.168.1.118:8080/kwfs/AAChTwAAADcAAwAc) HTTP/1.1 200 OK Server: QWS/1.0 Content-Type: application/octet-stream Connection: keep-alive Cache-Control: max-age=604800 Date: Sun, 09 Oct 2011 13:35:57 GMT Content-Length: 1239 Second backend: account yangqingchang@yqc:~$ curl -X GET -I [http://192.168.60.99:18000/account/visualconfirm/?page=register](http://192.168.60.99:18000/account/visualconfirm/?page=register) HTTP/1.1 200 OK Content-Length: 1044 Etag: “f91a3c56177d3edf13a96e0772410d23b531cef5” Content-Type: image/jpeg Server: TornadoServer/1.0 After kwfs response across nginx, “Transfer-Encoding: chunked” appeared in it’s headers , and “Content-Length” was replaced. First proxy: kwfs yangqingchang@yqc:~$ curl -X GET -I [http://192.168.60.96:8000/kwfs/AAChTwAAADcAAwAC](http://192.168.60.96:8000/kwfs/AAChTwAAADcAAwAC) HTTP/1.1 200 OK Date: Sun, 09 Oct 2011 13:58:07 GMT Content-Type: application/octet-stream Transfer-Encoding: chunked Connection: keep-alive Server: QWS/1.0 Cache-Control: max-age=604800 Second proxy: account yangqingchang@yqc:~$ curl -X GET -I [http://192.168.60.96:8000/account/visualconfirm/?page=register](http://192.168.60.96:8000/account/visualconfirm/?page=register) HTTP/1.1 200 OK Date: Sun, 09 Oct 2011 13:59:07 GMT Content-Type: image/jpeg Connection: keep-alive Content-Length: 1014 Etag: “bb6c20817a926b5ad761ec7a229f0f6d20adf1cb” Server: TornadoServer/1.0 I need the “Content-Length” for calculating the downloading process in client. But I really don’t know with same config, why “Content-length” missing when a special response proxy\_pass by nginx, and another is ok. Could anybody tell me why? Thanks a lot 🙂 My config: server { listen 192.168.60.96:8000; client\_max\_body\_size 2M; ``` location /kwfs { proxy_redirect off; proxy_pass_header Server; proxy_set_header Host $http_host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Scheme $scheme; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://192.168.1.118:8080; } location /account { proxy_redirect off; proxy_pass_header Server; proxy_set_header Host $http_host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Scheme $scheme; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass http://192.168.60.99:18000; } ``` } My nginx : nginx -V nginx version: nginx/0.7.65 built by gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5) TLS SNI support enabled configure arguments: --prefix=/usr/local/nginx-0.7.65 –with-http\_stub\_status\_module --with-http\_gzip\_static\_module –with-http\_ssl\_module --with-http\_realip\_module –with-openssl=/home/yangqingchang/Downloads/openssl-0.9.8l –with-pcre=/home/yangqingchang/Downloads/pcre-8.01 –add-module=/home/yangqingchang/Downloads/nginx\_upload\_module-2.0.12 Posted at Nginx Forum: > **[Content-length Missing when response proxy\_pass a special backend](https://forum.nginx.org/read.php?2,216427,216427#msg-216427)** > > I have 2 backends in my applications.There are pure backend response example: First backend: kwfs yangqingchang@yqc:~$ curl -X GET -I http://192.168.1.118:8080/kwfs/AAChTwAAADcAAwAc HTTP/1.1 200 OK Server: QWS/1.0 Content-Type:... ---
**Author:** ![fzuslide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/53a042/32.png) [@fzuslide](https://www.ruby-forum.com/u/fzuslide)\ **Post date:** [October 9, 2011, 10:56pm UTC](https://www.ruby-forum.com/t/content-length-missing-when-response-proxy-pass-a-special-backend/212650/2 "2011-10-09T22:56:08Z")
Hello! On Sun, Oct 09, 2011 at 10:26:37AM -0400, fzuslide wrote: […] > Content-Type: application/octet-stream > Transfer-Encoding: chunked […] > Content-Type: image/jpeg > Connection: keep-alive > Content-Length: 1014 […] > I need the “Content-Length” for calculating the downloading process in > client. > But I really don’t know with same config, why “Content-length” missing > when a special response proxy\_pass by nginx, and another is ok. > Could anybody tell me why? Thanks a lot 🙂 nginx removes Content-Length header (and uses chunked if possible) if resulting length after processing isn’t known. This happens e.g. if you use gzip, ssi, sub or addition modules. > My config: > > server { > listen 192.168.60.96:8000; […] > } You have to provide full config (i.e. what’s on http level?). Best guess without seeing your config is that you have ssi or something similar enabled for “application/octet-stream”, but not for “image/jpeg”. Maxim D. ---
**Author:** ![fzuslide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/53a042/32.png) [@fzuslide](https://www.ruby-forum.com/u/fzuslide)\ **Post date:** [October 10, 2011, 6:04am UTC](https://www.ruby-forum.com/t/content-length-missing-when-response-proxy-pass-a-special-backend/212650/3 "2011-10-10T06:04:19Z")
Hi, Maxim, Thanks for your replies. I got the reason when my partner check his code. Trouble shooting: If the backend did not set “Content-Length” or “Chunked” in headers , nginx will use chunked as default, but curl and firefox will use “Content-Length” as default. This makes me lose direction for the problem, lol. So if backend set “Content-Length” in his response headers, everything is ok! ``` Btw, If I want use gzip for downloading, is there any method ``` support use “Content-Length” ? I look up GzipStaticModule document, there is not introduction for this. With kind Regards! fzuslide Posted at Nginx Forum: > **[Re: Content-length Missing when response proxy\_pass a special backend](https://forum.nginx.org/read.php?2,216427,216449#msg-216449)** > > I have 2 backends in my applications.There are pure backend response example: First backend: kwfs yangqingchang@yqc:~$ curl -X GET -I http://192.168.1.118:8080/kwfs/AAChTwAAADcAAwAc HTTP/1.1 200 OK Server: QWS/1.0 Content-Type:...