nginx中使用Lua根據url參數長度跳轉到不同的upstream

一、需求

        項目中有這樣一個接口：使用get或post方式支持單個或批量的手機號加解密。

        使用Jmeter做性能測後發現，當批量加解密超過100個手機號時，吞吐量只有260左右【2顆E5CPU總計32核+128G DDR3】，所以我們想在nginx中通過lua實現如下功能：當手機號大於100個，用nginx-upstream-A，反之用nginx- upstream-B，A和B兩者互不影響。

二、設計

       

三、配置及代碼實現

1)server.conf

server {
        listen       80;
        server_name  chow.com.cn;
        access_log  /data/nginx/1.4.1/logs/chow/access.log main;
        set $target 'b.chow.com.cn';
        
        #支持lua中獲取request_body_data
        lua_need_request_body on;
        location / {
                #超時重試
                proxy_connect_timeout  60;
                proxy_send_timeout     60;
                proxy_read_timeout     60;
                proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
                proxy_next_upstream_tries 2;

                rewrite_by_lua_file /usr/local/nginx/conf/lua/proxy_pass_choice.lua;

                proxy_pass http://$target/;
        }
    }

2)upstream.conf

upstream  a.chow.com.cn{
       server 127.0.0.1:10001 weight=60;
       server 127.0.0.1:11001 weight=60;
     }
upstream  b.chow.com.cn{
       server 127.0.0.1:12001 weight=60;
       server 127.0.0.1:13001 weight=60;
     }

3)proxy_pass_choice.lua

local maxGetMethodUriArgsLength = 1024;
local maxPostMethodUriArgsLength = 1024;
local batchTarget = "a.chow.com.cn";

function getStringLength(str)
    if str == nil then
        return 0;
    else
        return string.len(str);
    end
end

function setTarget()
    if (ngx.req.get_method() == "GET")
    then
        if (getStringLength(ngx.var.args) > maxGetMethodUriArgsLength) then
            ngx.var.target = batchTarget;
        end
    else
        if (getStringLength(ngx.req.get_body_data()) > maxPostMethodUriArgsLength) then
            ngx.var.target = batchTarget;
        end
    end
end

function exceptionHandle(err)
    ngx.log(ngx.ERR, err);
end

--添加異常處理
xpcall(setTarget, exceptionHandle);