# Load balancing % available

**URL:** <https://www.ruby-forum.com/t/load-balancing-available/244451>\
**Category:** NGINX\
**Created:** [April 13, 2016, 11:25am UTC](https://www.ruby-forum.com/t/load-balancing-available/244451 "2016-04-13T11:25:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Sadaf\_N](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/858c86/32.png) [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\
**Post date:** [April 13, 2016, 11:25am UTC](https://www.ruby-forum.com/t/load-balancing-available/244451/1 "2016-04-13T11:25:15Z")

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Hello,  
I’m not yet an Nginx user, but have a question on it’s capacbility.

I’ve had a look at the http load balancer, but cannot see anything that  
would allow me to set the % or number of servers in an upstream backend  
group that should be available before an error response is returned.

The scenario I am looking into is one where Nginx can manage load  
balancing  
across servers in a tier and there are multiple tiers. If less than 50%  
servers are available in any tier I would like to respond with a HTTP  
failure and the hardware load balancer can then route traffic to a  
standby  
data centre.

If the status page returns information about all the servers in the  
group in  
each tier then perhaps some orchestrating check called by the hardware  
load  
balancer could detemine whether the site is considered available?

Is an orchestrating check available in Nginx and can % available be set?

I look forward to any responses.

Thanks  
Benson

Posted at Nginx Forum:

> **[load balancing % available](https://forum.nginx.org/read.php?2,266143,266143#msg-266143)**
>
> Hello, I'm not yet an Nginx user, but have a question on it's capacbility. I've had a look at the http load balancer, but cannot see anything that would allow me to set the % or number of servers in an upstream backend group that should be available...

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**Author:** ![benson9](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/ecd19e/32.png) [@benson9](https://www.ruby-forum.com/u/benson9)\
**Post date:** [April 13, 2016, 12:23pm UTC](https://www.ruby-forum.com/t/load-balancing-available/244451/2 "2016-04-13T12:23:05Z")

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As per the docs, I do not see a mean of doing what you wish directly in  
an  
upstream block.  
That cut-off might be a feature request you could post on their bug  
tracker.

In the meanwhile, you might parse data about servers from an upstream  
group  
on a status page you would have configured.  
However, the status module is only part of the commercial version of  
nginx,  
not the FOSS one. Have a look:

> **[Module ngx\_http\_status\_module](http://nginx.org/en/docs/http/ngx_http_status_module.html#status_zone)**
>
> The ngx\_http\_status\_module module provides access to various status information.

## That is the best answer I could provide you with. Maybe someone else could help you further?

_B. R._

On Wed, Apr 13, 2016 at 11:24 AM, benson9 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

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**Author:** ![benson9](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/ecd19e/32.png) [@benson9](https://www.ruby-forum.com/u/benson9)\
**Post date:** [April 13, 2016, 3:16pm UTC](https://www.ruby-forum.com/t/load-balancing-available/244451/3 "2016-04-13T15:16:00Z")

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On Wednesday 13 April 2016 12:21:52 B.R. wrote:

> As per the docs, I do not see a mean of doing what you wish directly in an  
> upstream block.  
> That cut-off might be a feature request you could post on their bug tracker.
> 
> In the meanwhile, you might parse data about servers from an upstream group  
> on a status page you would have configured.  
> However, the status module is only part of the commercial version of nginx,  
> not the FOSS one. Have a look:  
> [Module ngx\_http\_status\_module](http://nginx.org/en/docs/http/ngx_http_status_module.html#status_zone)

[..]

There is also a demo page that in more user-friendly way demonstrates  
most of  
the data provided by the status module.

[http://demo.nginx.com/status.html](http://demo.nginx.com/status.html)

and the raw json data as well:

[http://demo.nginx.com/status](http://demo.nginx.com/status)

wbr, Valentin V. Bartenev