Another year and another great performance by my programming students. They have already solved two problems and still have an hour left to go. Come on “Team Red C”! Hard work and dedication (we had to leave Samford at 5:30AM this morning and won’t get back until 10:30PM - 17 hours!)
Viva Las Vegas! After a three day drive that included quick visits to friends and family along the way in Texas and Arizona as well as brief visits to the Grand Canyon, Hoover Dam at night (very cool!), and finally to Las Vegas, I arrived just in time to showcase my Ajax Performance Monitor Toolkit. The kids love the pools here at the hotel including a wave pool and lazy river.
My presentation went well, and there seemed to be interest in the toolkit and porting it to work with other server-side scripting languages. Download the powerpoint slides (3.28MB). If you are interested in trying it out, you may also download a preliminary version of the toolkit (644KB) with a very limited amount of documentation.
The Samford Unviersity Virtual Supercomputer is coming soon! Today I gave a demonstration/presentation about the non-dedicated cluster I am building on campus. Eventually, it may grow into a supercomputer, but for now I am quite happy with the direction it is taking as a computational resource for campus. The Powerpoint Slides from my presentation are available, and I will post information about getting involved in the project to this site as the semester continues.
Tonight I am attending the executive committee meeting of the Alabama Academy of Science, where I am the editor for electronic media (i.e., I am in charge of the organization website). Tomorrow I will be chairing the Engineering and Computer Science presentations at the University of West Alabama in Livingston, Alabama. I did not submit a presentation this year, but I am looking forward to the six presentations from researchers across the state. The list of presentations is copied below and available on the Alabama Academy of Science website in the final program.
Wow - Sun microsystems has been busy - discreetly releasing and/or acquiring all kinds of important open source software projects. The banner of logos shown above just about summarizes it.
Today I discovered VirtualBox while working on a cluster computing project. VirtualBox isn’t directly related to cluster computing, but it can be used to run multiple compute nodes for testing. VirtualBox is an open-source equivalent to VMWare’s popular VMWare Workstation product. With the performance of today’s hardware, the ability to run multiple operating systems simultaneously on a single machine is becoming a reality for more and more people.
The basic idea is that by installing VirtualBox you install an application and a small set of services that allow you to create virtual machines for running an entirely different operating system in a window on your host operating system. I have just completed an install of the latest version of the Debian OS into a virtual machine. The entire process (including the several hundred megabyte download) took less than one hour to complete. Now I can boot up a Linux operating system whenever I want to run an application only available in Linux ( e.g., Kmines 
).
The screenshots below give you a glimpse into how it works. The first screenshot shows the virtual machine configuration options, which represents everything you would find on a real machine. The second shows Linux running in a window on my Windows Vista host operating system.
This morning we went live with Mesa Online, a website for students taking Spanish courses in the World Languages department. The idea behind the Mesa program is that students sign-up for a time to have lunch or dinner with a small group of students and one faculty member. During the lunch or dinner, all conversation must be in Spanish. The previous sign-up system involved a large list of timeslots posted on the wall. My Fall 2008 software engineering class took upon themselves the task of converting the paper-based system to an online system. I helped the students bring the project to a conclusion just in time for it to go live today for the Spring 2009 semester. As of 3:00PM, exactly 100 students have created their Mesa accounts. There is still work left to be done on the administrative part of the website, but I will post updates as the semester progresses and as we see whether the system effectively meets the needs of the World Languages Department here at Samford.
Welcome to another exciting semester at Samford University! Here is a quick summary list of the exciting classes and work just around the corner!
Update - Apparently it was about May of this year when there was a large surge in ssh password attacks. I believe that my computer became a target sometime after that. Here are some good articles reporting on the situation:
“Brute-Force SSH Server Attacks Surge” by InformationWeek
“Brute-force SSH attacks surge by SC Magazine
This may not be news to many of you, but my new home development machine is under attack! This isn’t your typical script kiddie HTTP attack, but rather a full-blown SSHD password guessing attack. Unfortunately, I did not take screenshots of everything as I detected the attack (which has been going on for about two weeks now) but I do have a few screenshots to help describe the timeline of events:
1 - I opened process explorer (an excellent replacement for the Windows Task Manager) to investigate my current cpu usage and running processes. The screenshot above doesn’t show it because I didn’t take a screenshot at the time, but what drew my attention to a possible attack was multiple sshd.exe processes appearing and then disappearing (brightly colored in red to indicate that the process was marked for destruction). My immediate instinct was that somebody was making connections and attempting to guess a password!
2 - I then instinctively (i.e., immediately and as fast as I could) opened a command prompt and typed the command netstat -a which shows the list of active TCP connections. Sure enough, there was a number of connections to static-217-133-194-98.clienti.tiscali.it
3 - Next I decided to see if the event viewer had recorded any activity. Wow! Over 30,000 events relating to sshd activity. The screenshot above shows the very first event recording a break-in attempt. On the evening of November 25, I switched my hardware firewall to redirect all port 22 SSH requests to my new computer. The next morning at 11:55:19 AM, the first attack commenced and proceeded to send a new username/password login attempt every 8 seconds for just over 1.5 hours ending at 1:19:19 PM. The attack sequence generated 2489 entries in the event viewer. You can see that the entry records a failed password guess for non-existent user root. The attacking computer then tried a different password before switching to a new user account ftp. Again, this is a non-existent user account. Then the user tried a second time with this user account before switching to another account: sales.
I am in the process of giving my Intro to Computer Science exam right now with two more exams to go after this one. I thought I would take a minute to update on a number of projects in the works:
One thing I have learned over the last week is that overclocking is challenging and somewhat addictive. I thought it was a simple tweak of the BIOS settings, but soon you find yourself tweaking the settings to try to get every last MHz out of your processor at the lowest possible voltage settings to avoid frying the motherboard and/or processor. “Frying” is a rather technical term referring to one of two things:
The other potentially bad thing that can happen with overclocking your processor is that your processor can stop operating correctly even while still being able to boot and load an entire operating system. This can trick you into thinking that your overclocked setup is working correctly when it really isn’t. A typical CPU can execute literally billions of instructions per second so if one or two or even twenty of those instructions executes incorrectly, the result may not even be noticable to a typical operating system or typical software applications that you run.
My architecture students should be able to tell you what happens if the clock rate is too high — signals do not have enough time to propagate to their final destination so an incorrect value will be written into memory or into a register before the newly calculated correct value arrives there.
That is why overclockers know that you can’t trust your setup until you run a few good benchmarks and at least one torture test. Two common torture tests that you can download and run for free are prime95 and Intel Burn Test.
I downloaded and installed prime95 and started to run it on what I thought was a stable 3.6 GHz overclock. It lasted less than a minute before crashing with a hardware failure. The way prime95 works is to perform a series of calculations and compare the results with known correct answers that are part of the data distributed with the program. If the calculated answer doesn’t match the known correct answer, then the only explanation is faulty hardware. Also, my CPU core temp started to approach the Intel thermal specification of 71deg celsius very quickly after raising the core voltage to increase stability. This is why overclockers need intricate cooling setups!
So I resolved to scale back my overclocked setup to 3.4 GHz, 800MHz memory speed, which is still a 20% overclock from the stock 2.83Ghz setting. With a core voltage setting of 1.26V, prime95 was able to run for 1 hour before I stopped it with temps just making it to 65deg celsius. I am using a cheap aftermarket air cooler so I am hesitant to let it run for longer without manually keeping an eye on the temp and shutting it down if it makes it up above 71deg celsius.
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Prime95 run - just over 5.5 hours with a CPU temp warning
As you can see in the screenshot, Prime95 has made it just over 5.5 hours without error after I left it running overnight. The ASUS software PC Probe II has popped up the temperature warning. By stealing CPU cycles from Prime95 and then idling the CPU during the ensuing context switch, the temperature warning also acts a very minor temperature governor.
