Dynamically loading upstream backends

rohit.c.joshi · 2015-08-31T23:39:53+00:00

Excellent, thank you Dejiang, this is working great for me.On Monday, August 31, 2015 at 10:00:48 PM UTC-4, DeJiang Zhu wrote:hi, RollinThis works only nginx...

Dynamically loading upstream backends

rohit.c.joshi

I have multiple upstream backends which are configured in upstream_backend.conf and included in nginx.conf file. Everytime I add/modify upstream backend, I have to restart nginx process.

One of the requirement is to dynamically load upstream backend without restarting nginx process. Can it be archieve using OpenResty?

NOTE: I am using open-resty lua module to dynamically route to upstream backend using the backend name.

agentzh

Hello!

On Mon, Aug 31, 2015 at 11:39 PM, RJoshi wrote:
> I have multiple upstream backends which are configured in
> upstream_backend.conf and included in nginx.conf file.  Everytime I
> add/modify upstream backend, I have to restart nginx process.
>  One of the requirement is to dynamically load upstream backend without
> restarting nginx process.  Can it be archieve using OpenResty?
>

This can be easily achieved with the upcoming balancer_by_lua*
directives in ngx_lua without any additional nginx C modules or nginx
core patches. In additon, you can easily configure very different set
of backend peers and fail-over strategies on the granularity of
individual requests without hassle.

Regards,
-agentzh

rohit.c.joshi

Thanks @agentzh.

1. Is alpha/beta version available for me to try balance_by_lua feature?

2. Does balance_by_lua support connection pool? If you look at upstream_backend, it allows to define connection pool.

On Monday, 31 August 2015 23:17:47 UTC-4, agentzh wrote:

Hello!

On Mon, Aug 31, 2015 at 11:39 PM, RJoshi wrote:
> I have multiple upstream backends which are configured in
> upstream_backend.conf and included in nginx.conf file. Everytime I
> add/modify upstream backend, I have to restart nginx process.
> One of the requirement is to dynamically load upstream backend without
> restarting nginx process. Can it be archieve using OpenResty?
>

This can be easily achieved with the upcoming balancer_by_lua*
directives in ngx_lua without any additional nginx C modules or nginx
core patches. In additon, you can easily configure very different set
of backend peers and fail-over strategies on the granularity of
individual requests without hassle.

Regards,
-agentzh

agentzh

Hello!

On Tue, Sep 1, 2015 at 9:59 PM, RJoshi wrote:
> 1.  Is alpha/beta version available for me to try balance_by_lua feature?

It's already implemented but I'm not allowed to share the code right
now. It'll get opensourced soon.

> 2.  Does balance_by_lua support connection pool? If you look at
> upstream_backend, it allows to define connection pool.
>

Yes, of course.

Regards,
-agentzh

davetropeano

Does this manipulate the underlying nginx upstreams or does the plugin implement its own upstream table and load balancing algorithms (like what the lua_resty_upstream plugin does @ https://github.com/hamishforbes/lua-resty-upstream) ?

On Monday, August 31, 2015 at 11:17:47 PM UTC-4, agentzh wrote:

Hello!

On Mon, Aug 31, 2015 at 11:39 PM, RJoshi wrote:
> I have multiple upstream backends which are configured in
> upstream_backend.conf and included in nginx.conf file. Everytime I
> add/modify upstream backend, I have to restart nginx process.
> One of the requirement is to dynamically load upstream backend without
> restarting nginx process. Can it be archieve using OpenResty?
>

This can be easily achieved with the upcoming balancer_by_lua*
directives in ngx_lua without any additional nginx C modules or nginx
core patches. In additon, you can easily configure very different set
of backend peers and fail-over strategies on the granularity of
individual requests without hassle.

Regards,
-agentzh

agentzh

Hello!

On Thu, Sep 10, 2015 at 10:03 PM, Dave Tropeano wrote:
> Does this manipulate the underlying nginx upstreams or does the plugin
> implement its own upstream table and load balancing algorithms (like what
> the lua_resty_upstream plugin does @
> https://github.com/hamishforbes/lua-resty-upstream) ?
>

It manipulate the underlying nginx upstream infrastructure. The syntax
looks like below:

    upstream foo {
        server 0.0.0.0;
        balancer_by_lua_file conf/balancer.lua;
    }

    server {
        location / {
            proxy_pass foo;
        }
    }

And you'll have an option of accessing the statically defined server
peers' information defined in the upstream {} configuration block or
dynamically generate a peer for the upstream infrastructure to access
on the fly. It's all about freedom and flexibility :)

Regards,
-agentzh

easedays

Looking forward you open source this feature.

On Thu, Sep 10, 2015 at 10:22 PM, Yichun Zhang (agentzh) <age...@gmail.com> wrote:

Hello!

On Thu, Sep 10, 2015 at 10:03 PM, Dave Tropeano wrote:
> Does this manipulate the underlying nginx upstreams or does the plugin
> implement its own upstream table and load balancing algorithms (like what
> the lua_resty_upstream plugin does @
> https://github.com/hamishforbes/lua-resty-upstream) ?
>

It manipulate the underlying nginx upstream infrastructure. The syntax
looks like below:

upstream foo {
server 0.0.0.0;
balancer_by_lua_file conf/balancer.lua;
}

server {
location / {
proxy_pass foo;
}
}

And you'll have an option of accessing the statically defined server
peers' information defined in the upstream {} configuration block or
dynamically generate a peer for the upstream infrastructure to access
on the fly. It's all about freedom and flexibility :)

Regards,
-agentzh.

fbudinsky

Hi @agentzh, any update on how soon balance_by_lua is going to be open sourced?

On Tuesday, September 1, 2015 at 10:43:16 AM UTC-4, agentzh wrote:

Hello!

On Tue, Sep 1, 2015 at 9:59 PM, RJoshi wrote:
> 1. Is alpha/beta version available for me to try balance_by_lua feature?

It's already implemented but I'm not allowed to share the code right
now. It'll get opensourced soon.

> 2. Does balance_by_lua support connection pool? If you look at
> upstream_backend, it allows to define connection pool.
>

Yes, of course.

Regards,
-agentzh

fbudinsky

On Thursday, September 10, 2015 at 10:22:41 AM UTC-4, agentzh wrote:

Hello!

And you'll have an option of accessing the statically defined server
peers' information defined in the upstream {} configuration block or
dynamically generate a peer for the upstream infrastructure to access
on the fly. It's all about freedom and flexibility :)

How about adding a totally new upstream (e.g., upstream bar { ... }) dynamically, which can then be the target of a proxy_pass? Is that also possible?

agentzh

Hello!

On Tue, Oct 27, 2015 at 10:00 PM,  <fbud...@gmail.com> wrote:
> Hi @agentzh, any update on how soon balance_by_lua is going to be open
> sourced?
>

Next couple of days. The first public version will be in a separate
github branch though. It needs more treatment before can be merged
into master.

> How about adding a totally new upstream (e.g., upstream bar { ... }) dynamically, which can then be the target of a proxy_pass? Is that also possible?
>

I don't see how this would be useful if we already have
balancer_by_lua. One can always define a generic upstream {} block
that can serve various different purposes on-the-fly according to the
current request's context anyway.

Regards,
-agentzh