Mac Mini? The coolest computer ever!

Apple has always been known for outstanding quality, however they’re use has been limited to a select group of dedicated “Mac People”. The landscape is changing… PC’s are no longer limited to beige box towers. The introduction of the iPhone shows how computers are jumping into different arenas. The Mac Mini is an illustration of how our perception of a computer is all wrong and we need to re-evaluate our assumptions and expectations. Computers don’t have to be noisy and don’t have to waste space and power. The Mac Mini makes a prefect media center machine and can be used as a server as well. It’s no surprise that there are companies selling Mac Mini’s within data centers (Mac Mini Hosting) as a replacement for expensive rack mount servers. These little machines have a genius design! They use very little power and have no annoying loud fans. Apple is really on top of their game when it comes to envisioning where the market is headed.

When it rains it pours! It’s hard enough to keep websites running without hackers trying to break in. An even worse situation is when hackers simply want you off-line. A few days ago I experienced just that… my first DDOS (distributed denial of service) attack against a high-profile website we host.

The attacker original exploited some legacy code to gain access to the web sites administration tool. After thwarting their attack, our web server immediately started to hit “max client connections”. Even after restarting Apache the max client connections were reached within seconds.

We quickly created bad routes for IP addresses associated with the hack attempts; however this did not resolve the problem. Below is the syntax we used to add bad routes.

Route add –host xxx.xxx.xxx.xxx reject

The Apache log files left no clues as to who was connecting so we had to look elsewhere. After some quick searching we found a terrific PHP script which shows which IP’s are connecting to your web server too much. The script was just want we needed. After about a ½ hour of blocking listed IP addresses the problem went away. In all we blocked a little over 100 IP addresses.

If you’re ever in a situation where Apache is clearly being flooded with connections. Run this script! It will save you a ton of time identifying the attacker(s).

– BEGIN SCRIPT –

<?php

## Functions ##

function getIP($line) {
        ereg("[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}",$line,$regMatch);
        $ip = $regMatch[0];
        if($ip) return $ip; else return "false";
}

function processString($string, $size = 18) {
        $string = "[ ".$string;
        $length = strlen($string);
        $toAdd = $size - $length;

        for($x = 0; $x < $toAdd; $x++) {
                $string = $string." ";
        }
        $string = $string."]";
        return $string;
}

## Code ##

while (true) {
        $cmd = "netstat -n | awk '{ print $5 }'";
        exec($cmd, $netstatArray);
        $ipArray = array();

        foreach($netstatArray as $line) {
                $ip = getIP($line);
                if($ip != "false" && ip != "127.0.0.1") {
                        if(array_key_exists($ip, $ipArray))
                                                 {
                                                                        $ipArray[$ip]+=1;
                                                 }
                                                 else // if not, count=1
                                                 {
                                                                        $ipArray[$ip] = 1;
                                                 }
                }
        }

        asort($ipArray);

        system("clear");
        foreach($ipArray as $ip => $count) {
                if ($count < 15)
                        continue;
                echo processString($ip);
                echo "\t" .processString(gethostbyaddr($ip), 55);
                echo "\tTimes Accessed: " .$count ."\n";
        }

        echo str_repeat("-", 50) ."\n";
        exec("top -n 1", $top_str);
        preg_match("#load average:(.+)#i", $top_str[0], $match);
        echo "Load Average: " .$match[1] ."\n";
        echo str_repeat("-", 50) ."\n";
        echo 'Showing $count >= 15: (Escape with ctrl+c)' ."\n";

        sleep(10);
}
?>

After being disappointed with Linux support for low-end SATA RAID cards I began searching for a controller card which would give me optimal performance, and complete Linux support. A few quick Google searches later I found a candidate. 3ware is a smaller company (now owned by AMCC) which builds an extensive line of SATA / ATA RAID cards. They also make their drivers open source, which allows for quick release of quality drivers. There is also a good amount of documentation on the Internet on how to compile your own drivers as well. They clearly build their product around the Linux environment.

For this test I am using the following equipment:
Dual 1.4GHz Athon MP CPUs
2GB SDRAM memory
3ware 9500S-4LP controller
3ware RAID Drive Cage
3x 36GB Western Digital 10K RPM SATA hard drives

During the installation I did have some problems using the 3ware 9500 SATA controller with Red Hat Enterprise 3. With some research in found the 2.4.xx kernel does not have support for the SATA controller in the original build however the 2.6.xx kernel does. They also gave additional documentation on how to compile your own driver into the 2.4.xx kernel to give you support. To keep this test simple I moved to a 2.6.xx kernel and everything installed perfectly.

Beyond the initial setup I found the BIOS and CLI to be simple, and powerful. They are not pretty, but they do everything I want them to do. During the initial hardware build I found the 3ware RAID cage to be well put together. Again I think this company focuses on keeping things simple. The drive bays were well built, but very simplistic.

It seems like they have a well support, quality product. Their website makes it easy to find drivers as well. Overall I was fairly happy with their product. We’re likely going to bring this server into the production early next week running MySQL. If all goes well; I will likely continue using their hardware for all my server RAID configurations.

I thought I would start my blog with some useful information specifically that Dell laptops suck. I hate to start off on a negative note, but I wanted to give everyone a heads up before they buy one of these paper weights. Maybe I’m just venting because I’ve had to ship defective drives back to Dell every two weeks. It just seems like over the last few years their quality has diminished.

Don’t get me wrong, their still better then the Packard Bell days. I’d also like to say their server / workstation lines are top-notch. At work we have a half-dozen or so laptops all of which have experienced some type of hardware failure. I’ve also noticed the durability isn’t what it was either. The laptop chassis, keyboard, and screen seem to be weak and fragile. The focus of my frustration is directed primarily at their Latitude D400 model. Between the random lockups, hard drive failures, and simple lack of processing power it finds it way to my desk about every two weeks.

This isn’t the only model with problems; we’ve had LCD fail on their entry level Latitude line-up as well. This is simply unacceptable; these laptops are under a year old, and lightly used.

MESSAGE TO MICHAEL DELL
If you’re going to sell junk at least make it easy to return! Sitting on the phone with technical support and having to convince them of a bad LCD shouldn’t take a half hour.

After careful consideration; I’ve decided to start the migration to an IBM only policy. Although I have far less experience with the IBM ThinkPad then the Dell Latitude, every bit of information points to a better product all around. I’ll post again once I get a few new IBM ThinkPad’s to test.