cnscud / lua-resty-upstream-healthcheck

Health Checker: 加强内容校验 + 暂停peer (pause peer)

Name

fork from https://github.com/openresty/lua-resty-upstream-healthcheck

just for enhance.

lua-resty-upstream-healthcheck - Health-checker for Nginx upstream servers

修改人

@author Felix Zhang

说明

1. 增加: 健康检查的是否支持内容校验, 当然一般用简单的内容标识运行正常.
2. 增加: 利用health check的定时和共享内存暂停和恢复peer, 一般用于静态upstream的临时发布摘除.
3. 示例: 多个upstream的监控检查

你可能需要知道的 (但是这里不提供的)

1. 如果需要动态增删upstream里面的server, 你可以使用

   • openresty/lua-resty-balancer
   • upyun/lua-resty-checkups
   • weibocom / nginx-upsync-module
   • yzprofile / ngx_http_dyups_module (或者 Tengine )

2. 如果你有多台机器, 可以使用redis来存放共享内存的内容

3. 如果不需要健康检查, 自己实现一个定时机制, 供worker自己更新自己的状态 (copy healthcheck 然后去除多余的代码)

示例: 健康检查 (多个upstream + 内容检查)

init_worker_by_lua_block {
        local hc = require "resty.upstream.healthcheck"

        local hostnamebyupstream = {
            ["web1"] = {"www.yourdomain.com"},
            ["img1"] = {"f1.yourdomain.cn", "/ping.txt"}
        }

        for k, v in pairs(hostnamebyupstream) do
                local myhost = v[1]
                local pingurl
                local reqstr

                if #v >1 then
                    pingurl = v[2]
                else
                    pingurl = "/ping/"
                end

                if myhost == nil then
                    reqstr = "GET "..pingurl.." HTTP/1.0\r\n\r\n"
                else
                    reqstr = "GET "..pingurl.." HTTP/1.0\r\nHost: "..myhost.."\r\n\r\n"
                end

                local ok, err = hc.spawn_checker{
                    shm = "healthcheck",  -- defined by "lua_shared_dict"
                    upstream = k, -- defined by "upstream"
                    type = "http",
                    http_req = reqstr,
                    interval = 3000,  -- run the check cycle every 2 sec
                    timeout = 1000,   -- 1 sec is the timeout for network operations
                    fall = 3,  -- # of successive failures before turning a peer down
                    rise = 2,  -- # of successive successes before turning a peer up
                    valid_statuses = {    200, 302     },
                    valid_response = "pong", -- check body
                    concurrency = 10,  -- concurrency level for test requests
                }

                if not ok then
                    ngx.log(ngx.ERR, "failed to spawn health checker: ", err)
                    return
                end
        end
}

示例2: 用url方式暂停upstream的peer (必须和healthcheck一起工作, 否则无效)

# 参数: upstream名字  server=ip:port status=要切换的状态: true/false
location /upstream_pause {
    default_type 'text/plain';

    content_by_lua_block {

            local u = ngx.var.arg_upstream
            local server_ip = ngx.var.arg_ip
            local server_port = ngx.var.arg_port
            local pausestatus = ngx.var.arg_pause

            ngx.log(ngx.WARN, "info ", u, server_ip, server_port, tostatus)

            local up = require "resty.upstream.upstreampause"

            local ok, err = up.pause{
                ip = server_ip, port = server_port, upstream = u, pause = pausestatus,
                shm = "healthcheck" -- should same with health check now
            }

            if not ok then
                ngx.say("failed to call upstream pause: " .. err)
                return
            else
                ngx.say("ok")
            end
    }
}

调用方法:

• curl "http://192.168.6.99/upstream_pause/?upstream=web1&ip=192.168.6.22&port=8001&pause=true"
• curl "http://192.168.6.99/upstream_pause/?upstream=web1&ip=192.168.6.22&port=8001&pause=false"