init_worker_by_lua.md

init_worker_by_lua

语法: init_worker_by_lua <lua-script-str>

环境: http

阶段: starting-worker

开启master进程模式，Nginx工作进程启动时执行指定的Lua代码。关闭master模式，将在init_by_lua*后直接运行。

这个指令经常被用来创建单进程的反复执行定时器（通过ngx.timer.at Lua API创建），可以是后端服务健康检查，也可以是其他定时的日常工作。下面是个例子：

 init_worker_by_lua '
     local delay = 3  -- in seconds
     local new_timer = ngx.timer.at
     local log = ngx.log
     local ERR = ngx.ERR
     local check

     check = function(premature)
         if not premature then
             -- do the health check or other routine work
             local ok, err = new_timer(delay, check)
             if not ok then
                 log(ERR, "failed to create timer: ", err)
                 return
             end
         end
     end

     local ok, err = new_timer(delay, check)
     if not ok then
         log(ERR, "failed to create timer: ", err)
         return
     end
 ';

这个指令是在v0.9.5发行版第一次引入。

返回目录

English source:

init_worker_by_lua

syntax: init_worker_by_lua <lua-script-str>

context: http

phase: starting-worker

Runs the specified Lua code upon every Nginx worker process's startup when the master process is enabled. When the master process is disabled, this hook will just run after init_by_lua*.

This hook is often used to create per-worker reoccurring timers (via the ngx.timer.at Lua API), either for backend healthcheck or other timed routine work. Below is an example,

 init_worker_by_lua '
     local delay = 3  -- in seconds
     local new_timer = ngx.timer.at
     local log = ngx.log
     local ERR = ngx.ERR
     local check

     check = function(premature)
         if not premature then
             -- do the health check or other routine work
             local ok, err = new_timer(delay, check)
             if not ok then
                 log(ERR, "failed to create timer: ", err)
                 return
             end
         end
     end

     local ok, err = new_timer(delay, check)
     if not ok then
         log(ERR, "failed to create timer: ", err)
         return
     end
 ';

This directive was first introduced in the v0.9.5 release.

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