# 499 error **URL:** \ **Category:** NGINX\ **Created:** [December 1, 2011, 9:20am UTC](https://www.ruby-forum.com/t/499-error/214405 "2011-12-01T09:20:32Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![dubstep](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/cdc98d/32.png) [@dubstep](https://www.ruby-forum.com/u/dubstep)\ **Post date:** [December 1, 2011, 9:20am UTC](https://www.ruby-forum.com/t/499-error/214405/1 "2011-12-01T09:20:32Z")
I have a configuration that uses nginx + unicorn + rails 3.1. I have a load balancer in front of this, and the health checks are failing because nginx is sending a 499 response when I try to use a rails page for the health check. I can see that the rails response was a 200 from the logs, but nginx turns this into a 499. I understand that this means the client closed the connection, but its idle timeout is 60 seconds, and the rails log shows consistent sub-1 second response times. There’s a second, more frequent health check that just opens a TCP connection on port 80 and only validates that the connection was opened. When I use a static page (either from rails public directory or from another directory), everything’s fine. I cannot figure out why nginx is sending this 499 response – one page indicated it was because of not having the host in the request ([http://www.docunext.com/blog/2009/09/nginx-499-error.html](http://www.docunext.com/blog/2009/09/nginx-499-error.html)), but I set the host in my nginx config to a hardcoded hostname, and still no luck. I am very confused. I can paste config files if that helps. Here’s a look at the logs, both from rails and from nginx: Rails (the Host: X.X.X.X line is added from the controller for debug purposes and is actually the IP address of the server): Started GET “/health\_check” for 127.0.0.1 at Thu Dec 01 08:11:05 +0000 2011 Processing by HealthChecksController#do\_health\_check as _/_ ^[[1m^[[35mHealthCheck Load (0.1ms)^[[0m SELECT “health\_checks”.\* FROM “health\_checks” LIMIT 1 ^[[1m^[[36m (0.2ms)^[[0m ^[[1mUPDATE “health\_checks” SET “curr” = ‘2011-12-01 08:11:06.000000’, “prev” = ‘2011-12-01 08:10:35.000000’, “updated\_at” = ‘2011-12-01 08:11:06.019519’, “check\_count” = 157 WHERE “health\_checks”.“id” = 2^[[0m Host: X.X.X.X Rendered health\_checks/do\_health\_check.html.erb within layouts/application (0.4ms) Completed 200 OK in 70ms (Views: 25.9ms | ActiveRecord: 0.7ms) Started GET “/health\_check” for 127.0.0.1 at Thu Dec 01 08:11:35 +0000 2011 Processing by HealthChecksController#do\_health\_check as _/_ ^[[1m^[[35mHealthCheck Load (0.1ms)^[[0m SELECT “health\_checks”.\* FROM “health\_checks” LIMIT 1 ^[[1m^[[36m (0.2ms)^[[0m ^[[1mUPDATE “health\_checks” SET “prev” = ‘2011-12-01 08:11:06.000000’, “check\_count” = 158, “curr” = ‘2011-12-01 08:11:35.000000’, “updated\_at” = ‘2011-12-01 08:11:35.926096’ WHERE “health\_checks”.“id” = 2^[[0m Host: X.X.X.X Rendered health\_checks/do\_health\_check.html.erb within layouts/application (0.4ms) Completed 200 OK in 36ms (Views: 12.9ms | ActiveRecord: 0.6ms) nginx: X.X.X.X - - [01/Dec/2011:07:57:05 +0000] “GET /health\_check HTTP/1.1” 499 0 “-” “HealthChecker/1.0” X.X.X.X - - [01/Dec/2011:07:57:15 +0000] “-” 400 0 “-” “-” X.X.X.X - - [01/Dec/2011:07:57:25 +0000] “-” 400 0 “-” “-” X.X.X.X - - [01/Dec/2011:07:57:35 +0000] “-” 400 0 “-” “-” X.X.X.X - - [01/Dec/2011:07:57:35 +0000] “GET /health\_check HTTP/1.1” 499 0 “-” “HealthChecker/1.0” Posted at Nginx Forum: > **[499 error](https://forum.nginx.org/read.php?2,219411,219411#msg-219411)** > > I have a configuration that uses nginx + unicorn + rails 3.1. I have a load balancer in front of this, and the health checks are failing because nginx is sending a 499 response when I try to use a rails page for the health check. I can see that the... ---
**Author:** ![lsdillard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/5e9695/32.png) [@lsdillard](https://www.ruby-forum.com/u/lsdillard)\ **Post date:** [December 1, 2011, 11:14am UTC](https://www.ruby-forum.com/t/499-error/214405/2 "2011-12-01T11:14:35Z")
Hello! On Thu, Dec 01, 2011 at 03:20:12AM -0500, lsdillard wrote: > directory), everything’s fine. I cannot figure out why nginx is sending > this 499 response – one page indicated it was because of not having the > host in the request The 499 response is never send, it’s just as status for logs to show that client closed connection before nginx was able to reply anything. You description suggests that load balancer uses half-closed tcp connection for health checks (i.e. shuts down it’s part of a tcp connection after sending request). This will result in 499 for proxied requests, as nginx will detect connection close from client and will terminate request. You may use ``` proxy_ignore_client_abort on; # or fastcgi_ignore_client_abort, whatever you use ``` to prevent nginx from doing connection close checks. It will stop it from detecting connection close from clients as well though, so you may want to limit this setting to health checks only by adding separate location for health checks. Alternatively, you may want to fix your load balancer to keep connection open, not half-closed. Maxim D. ---
**Author:** ![lsdillard](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/5e9695/32.png) [@lsdillard](https://www.ruby-forum.com/u/lsdillard)\ **Post date:** [December 7, 2011, 11:21pm UTC](https://www.ruby-forum.com/t/499-error/214405/3 "2011-12-07T23:21:26Z")
Thanks – that addressed my issue for now by setting proxy\_ignore\_client\_abort on. Will see what I can do for other aspects of the issue, but it got me past the problem. Posted at Nginx Forum: > **[Re: 499 error](https://forum.nginx.org/read.php?2,219411,219775#msg-219775)** > > I have a configuration that uses nginx + unicorn + rails 3.1. I have a load balancer in front of this, and the health checks are failing because nginx is sending a 499 response when I try to use a rails page for the health check. I can see that the...