I had a scalability problem at work. Having about 3k customers with an average of 500 – 600 concurrent sessions and a middle aged all-in-one server, I have to balance http and https connections at least over 2 servers without changing the main IP address used by the client to start the application.

 

At the beginning, I evaluated Nginx, which is a well established http server (known for its outstanding capability on serving static resources) that has the capability to proxy requests to a pool of servers. I left this road quickly when I noticed that the proxy capability of Nginx does not supports (yet) sticky-sessions. In fact, when session affinity is required, Nginx can only route connection using source IP address as selection key, loosing the round-robin capability based on weight (that I need because I have server with different strength).

 

Looking for a balancer that supports weighted backend as long as affinity sessions, I foundHAProxy, which is considered the de-facto solution for this kind of problem. Again, evaluating this solution, I found something that bother me: HAProxy, in its stable version, can balance only http connection; it does not have support for https, which I need for my next version of the app.

Read more at: http://blog.towerengineering.it/2012/12/load-balancing-with-nginx-and-haproxy-1/

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Yesterday Twitter announced that it was moving away from client-side rendering back to server-side rendering in order to improve page load time. Today I found myself having to defend my position that server-side rendering will almost always be faster. I figured I’d blog about it.

I want to point out a couple things. First, I’m talking specifically about render performance and page speed. There might be other compelling advantages to thick-clients; I’m talking about performance. Secondly, I’m going to get on a high horse here and say that it worries me that developers think client-side rendering is faster. This is basic and fundamental knowledge about how the web and browsers work. Maybe I’ll be proven wrong. If I am, I’ll admit it. It’ll be embarrassing because it means that I don’t know the fundamentals. But I’ll be glad to have learned (which is why I blog).
Read more at: http://openmymind.net/2012/5/30/Client-Side-vs-Server-Side-Rendering/

Roundup of Useful Bootstrap Tools and Generators

As we have mentioned previously, Twitter Bootstrap, being a complex yet quite intuitive framework for building websites, has numerous ready-to-use themes and templates that are made for those who want to quickly prototype its project. It includes numerous features as well as third-party jquery-based extensions that all together contribute to development.

Today we are going to take a look at other helpful assistants that were designed in order to even more lessen your efforts and save your time while the programming. We have listed useful Bootstrap tools and generators that embrace different aspects, providing integral instruments for creating marvelous web interfaces.

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Read more at: http://ewebdesign.com/bootstrap-tools-generators/

I was trying to get a directory size with PHP under a *nix environment…
This is what I’v found on stackoverflow… and it works 🙂

**
 * Get the directory size
 * @param directory $directory
 * @return integer
 */
function dirSize($directory) {
    $size = 0;
    foreach(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($directory)) as $file){
        $size+=$file->getSize();
    }
    return $size;
}

And to get it with Kb, Mb, Gb etc….

 function formatSizeUnits($bytes)
    {
        $symbols = array('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
        $exp = floor(log($bytes) / log(1024));
        @$bytes = sprintf('%.2f ' . $symbols[$exp], ($bytes / pow(1024, floor($exp))));
        return $bytes;
}

“People move to the cloud for perceived cost savings and what we’re finding is it gets really expensive compared to colocation, [particularly] if you look at the three-year overall total cost of ownership of an application that is pretty constant,”
By Raj Dutt, senior VP of technology at Internap
Read more at http://virtualizationreview.com/Blogs/The-Schwartz-Cloud-Report/2013/02/Does-Cloud-Computing-Reduce-IT-Costs.aspx#

I’m gonna let here some paragraphs of a nice article from serverdensity.com geeks blog, explaining their choices/ideias cloud vs rented vs colocation with their point of view is also the same that I have about getting our own servers instead of use clouds or rented servers –

Before the paragraphs from serverdensity i’m gonna let some maths that i’v made 3 weeks ago… rackspace vs our own servers (dell).

rackspace clouds with 2Gb RAM / 80Gb disk – web and sql vs colocation dell 2Gb RAM / 500Gb disk and rackspace clouds with 8Gb RAM / 320Gb disk – web and sql vs colocation dell 8Gb RAM / 500Gb disk

Continue reading cloud vs colocation →