03. Nginx Advanced Usuage

How to manage session using clustering systems

1. ip_hash
   Other-Hash: $cookie_jsessionid, $request_uri;
   lua logic redirect
2. Redis + SpringSession

hash

1. inner ip_hash

upstream httpget{
  ip_hash;
  server 192.168.1.1;
  server 192.168.1.2;
}

只适用于中小型项目

• Drawbacks:
  1. ip 集中
  2. 后端服务器宕机

2. $cookie_jsessionid

upstream httpget{
  hash $cookie_jsessionid;
  server 192.168.1.1;
  server 192.168.1.2;
}

3. $request_uri

upstream httpget{
  hash $request_uri;
  server 192.168.1.1;
  server 192.168.1.2;
}

• suit for
  1. No cookies supported
  2. Uneven distribution of resources

sticky

Sticky on Bitbucket
Sticky on Github

Compile nginx with Sticky:

./configure --prefix=/usr/local/nginx --add-module=/root/nginx-sticky-module-ng-folder

Info

Sometimes there has some errors during compiling because of the version of sticky is too old.
can add the following headers to ngx_http_sticky_misc.h for resolving some problems caused by openssl

#include <openssl/sha.h>
#include <openssl/md5.h>

How to configure sticky

Basic Configuration

upstream httpget{
  sticky;
  server 192.168.1.1;
  server 192.168.1.2;
}

Configuration Sticky-cookie-name

upstream httpget{
  sticky name-NewName;
  server 192.168.1.1;
  server 192.168.1.2;
}

Info

Need to restart nginx

Keepalive

For some resource, to configue the cache is more suitable, such as javascripts/css.
For some api, it's hard to request the second time, which need to close keepalive.

upstream http_servers {
  keepalive 100;
  keepalive_requests 1000;
  keepalive_timeout 65;
  server 192.168.1.1;
  server 192.168.1.2;
}
server{
  listen 80;
  server_name localhost;
  location / {
    proxy_http_version 1.1;  # configure the version of http protocal
                             # default version is 1.0, need to add header "Connection: keep-alive" (default value is close) to support keep_alive
                             # http 1.1 support it by default
    proxy_set_header Connection ""; # or set as keep-alive
    proxy_pass http://http_servers;
  }
}

How to configure

http{
  # keepalive_timeout 65 65; # Add two value for http protocal 1 to add header `keep Alive: timeout=65`
  keepalive_timeout 65; # (units:seconds) set 0 to disable the function
  keepalive_time 1h; # Maximum time for keep keepalive
  keepalive_request 1000; # The maximum request for one connection

  # Be careful with this configuration
  send_timeout 60; # The connection will be closed for some time-consuming operation
}

For more configuration please refer to nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive_time

Charles Proxy

Stress test Tool - Apache Benchmark

Install

yum install httpd-tools

Test

ab -n 100000 -c 30 http://192.168.1.1/

How nginx works

Nginx reverse proxy, memory and file buffer

proxy_buffering on;