I need to duplicate/mirror the traffic comming to my server/resource.

I mean, I have server A and B and N (nginx) as webserver.

All the traffic comming to N/resource --> redirect to both A and B

Is it possible?

  • 2
    You probably don't want to do this. What are you really trying to do? – Michael Hampton Jun 6 '13 at 20:25
  • 1
    I really need it to do it – Agus Jun 7 '13 at 12:44
  • 2
    I have a use case. I have a client pushing data to my servers that our production infrastructure uses. I need the exact same data pushed to my dev servers to further development. The client is only capable of sending the data to 1 endpoint. Don't ask why, I don't know. – The Dude Jun 7 '13 at 18:01
  • 1
    Oh I need to duplicate traffic, I mean the traficc will process by A, but B will recevid make offline process – Agus Jun 7 '13 at 19:29
  • 2
    I found another version of this question with an answer that helped me: serverfault.com/a/515531/175380 Basically, you set the location to be mirrored up in a post_action directive. This will run after the request has been satisfied by the production machine. – Adam Lukens Jul 29 '15 at 5:18

Nginx now has an http mirror module. Documentation is at https://nginx.org/en/docs/http/ngx_http_mirror_module.html

Example configuration from the documentation:

location / {
    mirror /mirror;
    proxy_pass http://backend;

location /mirror {
    proxy_pass http://test_backend$request_uri;
| improve this answer | |
  • Is there a way that I can use a mirror even if one of the host is down, I have a use case for that. – Sagar Kharab Jan 29 '19 at 12:58

Here is new feature from nginx (1.13.4): http://nginx.org/en/docs/http/ngx_http_mirror_module.html#mirror

The ngx_http_mirror_module module (1.13.4) implements mirroring of an original request by creating background mirror subrequests. Responses to mirror subrequests are ignored.

| improve this answer | |

Based on their README It looks that GOR could help you solving your problem.

I never used it before, just stumbled upon it this week, so good luck!

| improve this answer | |
  • Hey on using GOR it just acknowledges with a http 200. So if he has a response object or validation he wants done with what the client is sending him I dont think this will work for him. As far as I can tell, and I'm new to Gor, you can't pass on the result object from one of your output segments. – PatrickWalker Sep 7 '15 at 12:41
  • We are testing GOR right now and we have a couple of problems. It interprets headers like: Location: //newpath generating requests like GET //newpath. Redirects loose original headers (including host useragent etc.) We are migrating to another tool. – Aalex Gabi Aug 27 '18 at 14:43

you cannot mirror requests with NGINX but the request is available as a variable. You could use Lua scripting to send that variable to a third party server as a sub request though. http://nginx.org/en/docs/http/ngx_http_core_module.html#var_request

| improve this answer | |
  • Would you have an example of this? I'm looking for exactly the same – Lobo May 18 at 18:55

After digging and digging I found a solution. You can see it here Copy and deliver a request to another nginx server for real traffic testing by @scari

Just thought I should mention it here to ease the search for other people. On my setup I didn't use uwsgi - instead I wanted to duplicate every incoming request to an additional servers (in addition to the backbones servers that was load balanced already.

Hope it will help,

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.