# Poor load balancer performance on rackspace and centos

**URL:** <https://www.ruby-forum.com/t/poor-load-balancer-performance-on-rackspace-and-centos/212981>\
**Category:** NGINX\
**Created:** [October 19, 2011, 10:10pm UTC](https://www.ruby-forum.com/t/poor-load-balancer-performance-on-rackspace-and-centos/212981 "2011-10-19T22:10:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [October 19, 2011, 10:10pm UTC](https://www.ruby-forum.com/t/poor-load-balancer-performance-on-rackspace-and-centos/212981/1 "2011-10-19T22:10:38Z")

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I am load testing different options for load balancing, and am getting  
poor results from Nginx, haproxy, and varnish. I have one 4GB instance  
at Rackspace, hitting 4x1GB app servers.

I’m hitting a url called “/slow” which deliberately waits 500ms before  
responding. If I hit an application server directly it can handle a  
connection rate of 1600-1800 per second.

If I hit the Nginx load balancer, it can only handle about 2000  
connections. I was hoping for something closer to 4x1600 = 6000. Below  
is the command I’m using to test it. This is run in parallel on 40 256  
MB instances. I’m deliberately setting num\_call to 1, because I want to  
see connection performance. Any higher than this and I start to get a  
lot of errors.

```
httperf --server 50.56.80.227 --port 1555 --uri /slow --rate 50

```

–num-call 1 --num-conn 100 --timeout 5

Here is my nginx config: [nginx config · GitHub](https://gist.github.com/1299501)

So, here’s the weird thing, no matter whether I use nginx, haproxy, or  
varnish, I get roughly the same results. However, I tested Rackspace’s  
new cloud balancers, and they get much better performance (doing fine at  
7000/s). Since nginx and the others are all running on an instance I set  
up, and the rackspace balancer isn’t, I’m guessing there’s something  
about the system that is wrong. I’d rather use a balancer I control, so  
I can add caching, gzip, ssl, and other stuff to it.

How can I find out what the bottleneck is? Is there anything I should  
tweak on the system to get performance to be better? Do I need more than  
4GB of ram? (Ram usage is not high during the test). Any other random  
ideas?

Thank you for your help!  
~sean

Posted at Nginx Forum:

> **[Poor load balancer performance on rackspace and centos](https://forum.nginx.org/read.php?2,216935,216935#msg-216935)**
>
> I am load testing different options for load balancing, and am getting poor results from Nginx, haproxy, and varnish. I have one 4GB instance at Rackspace, hitting 4x1GB app servers. I'm hitting a url called "/slow" which deliberately waits...

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<div class="post-metadata">

**Author:** ![seanhess](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/db5fbb/32.png) [@seanhess](https://www.ruby-forum.com/u/seanhess)\
**Post date:** [October 19, 2011, 11:20pm UTC](https://www.ruby-forum.com/t/poor-load-balancer-performance-on-rackspace-and-centos/212981/2 "2011-10-19T23:20:23Z")

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Hi Sean,

I work at Rackspace and would be happy to connect you with one of our  
techs about this. Email me at mw at rackspace dot com and I’ll set up a  
call for you.

Best,  
Matt Wilbanks

Posted at Nginx Forum:

> **[Re: Poor load balancer performance on rackspace and centos](https://forum.nginx.org/read.php?2,216935,216936#msg-216936)**
>
> I am load testing different options for load balancing, and am getting poor results from Nginx, haproxy, and varnish. I have one 4GB instance at Rackspace, hitting 4x1GB app servers. I'm hitting a url called "/slow" which deliberately waits...