id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
2060	Nginx doesn't take case http_502 as unsuccessful attempt in ngx_http_grpc_module	AbacusHu@…		"From the nginx document [http://nginx.org/en/docs/http/ngx_http_grpc_module.html], syntax ""grpc_next_upstream error timeout http_502;"" is valid and case http_502 will take as unsuccessful attempt. However, Nginx doesn't take case http_502 as unsuccessful attempt in fact.

Below is an example. A grpc client sent request to nginx server every seconds, and nginx kept sending request to the upstream server which returned 502 and the other one in round-robin way. Nginx didn't take case http_502 as unsuccessful attempt. 

nginx config file:

{{{
upstream testserver {
  server 10.46.46.161:9999 max_fails=1 fail_timeout=60; # another nginx server which can retrun responses with error code 502.
  server 10.46.46.160:9999; # a server which can retrun normal responses with status code 200.
}

server {
  listen 8888 http2;
  location /com.company.test {
    grpc_pass grpc://testserver;
    grpc_next_upstream error timeout http_504 http_502 non_idempotent;
  }
}
}}}



access log file:
{{{
[11:24:40 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 502|| 150|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.000|| 0.001|| 10.46.46.161:9999|| 502
[11:24:41 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 200|| 28|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.003|| 0.003|| 10.46.46.160:9999|| 200
[11:24:42 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 502|| 150|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.000|| 0.001|| 10.46.46.161:9999|| 502
[11:24:43 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 200|| 28|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.005|| 0.005|| 10.46.46.160:9999|| 200
[11:24:44 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 502|| 150|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.001|| 0.000|| 10.46.46.161:9999|| 502
[11:24:45 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 200|| 28|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.005|| 0.004|| 10.46.46.160:9999|| 200
[11:24:46 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 502|| 150|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.000|| 0.001|| 10.46.46.161:9999|| 502
[11:24:47 +0000]|| ""POST /com.company.test/order HTTP/2.0""|| 200|| 28|| ""-""|| grpc-java-netty/1.17.2|| -|| 0.003|| 0.003|| 10.46.46.160:9999|| 200
}}}
"	defect	accepted	minor		nginx-module	1.15.x		ngx_http_grpc_module, unsuccessful attempt, http_502		Linux tradecenter-01 3.10.0-693.el7.x86_64 #1 SMP Thu Jul 6 19:56:57 EDT 2017 x86_64 x86_64 x86_64 GNU/Linux	"nginx version: nginx/1.15.5
built by gcc 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) 
built with OpenSSL 1.0.2k-fips 26 Jan 2017
TLS SNI support enabled
configure arguments: --user=nginx --group=nginx --prefix=/opt/nginx --with-http_stub_status_module --with-http_ssl_module --with-http_v2_module --with-stream"