Release resource in Master process

prdevel006 · 2014-05-26T15:56:34+00:00

Hello! On Mon, May 26, 2014 at 6:10 AM, hugh wrote: > Yes, i saw that, but it does not explain where to set the keys in Lua only > in nginx.conf. i su...

Release resource in Master process

prdevel006

Hi,

Is there a way to release resource in master process when the worker process dies?

agentzh

Hello!

On Mon, May 26, 2014 at 12:56 AM, Pravin tatti wrote:
> Is there a way to release resource in master process when the worker process
> dies?
>

I wonder why you actually need this. Because the worker processes can
never allocate resources in the master anyway. And when the worker
dies, the master automatically forks a new one immediately.

What kind of "resource" do you want to release here?

Regards,
-agentzh

prdevel006

I am using Modsecurity + Nginx if you see the modsec plugin for nginx. All the rules and all hooks are registered and allocated in master process and forks so that worker can use it. There is no way for me release this resource once worker dies due to reload hence there is a memory leak. I am not sure why they allocated all the memory in master process even though they don't use it?

On Fri, May 30, 2014 at 9:39 AM, Yichun Zhang (agentzh) <age...@gmail.com> wrote:

Hello!

On Mon, May 26, 2014 at 12:56 AM, Pravin tatti wrote:
> Is there a way to release resource in master process when the worker process
> dies?
>

I wonder why you actually need this. Because the worker processes can
never allocate resources in the master anyway. And when the worker
dies, the master automatically forks a new one immediately.

What kind of "resource" do you want to release here?

Regards,
-agentzh
.

agentzh

Hello!

On Fri, May 30, 2014 at 5:10 AM, Pravin tatti wrote:
> I am using Modsecurity + Nginx if you see the modsec plugin for nginx. All
> the rules and all hooks are registered and allocated in master process and
> forks so that worker can use it. There is no way for me release this
> resource once worker dies due to reload hence there is a memory leak. I am
> not sure why they allocated all the memory in master process even though
> they don't use it?
>

We have never seen such leaks in our own (and the standard) nginx
modules. It looks like a bug in your modsecurity pluggin (or some
other 3rd-party modules you're using) and you should really report the
issue to their authors instead.

I did see some buggy 3rd-party nginx modules did have such leaks upon
HUP reload in past, for example, the healthcheck_nginx_upstreams
module:

    https://github.com/cep21/healthcheck_nginx_upstreams

Actually I've just checked its source and found that it still has the
leak nowadays:

 https://github.com/cep21/healthcheck_nginx_upstreams/blob/master/ngx_http_healthcheck_module.c#L776

Best regards,
-agentzh