January 2009

HOW TO : Microsoft Windows – Routing to /dev/null

Ran into an interesting issue at work today and wanted to document it. We had a rouge process in one of our applicatoins and it was trying to send e-mails via one of our mail gateways at an alarming rate..There was no customer impact, since the mail server was rejecting all the connections. But the high number of connections were causing a strain on our firewalls..

If this was Linux, we would have done something simple like adding a route to point all the traffic destined to mail server to /dev/null by running “route add IP_ADDRESS_OF_MAIL_SERVER MASK /dev/null

A search on Google showed that you can achieve similar results by doing the following “route ADD IP_ADDRESS_OF_MAIL_SERVER MASK 255.255.255.255 127.0.0.1“. 127.0.0.1 being the IP address of the loopback interface in this case. But when we ran the command, we got an error “incorrect gateway 127.0.0.1”.. So there is NO way to route traffic in Microsoft Windows to a null device..

Finaly, we figured out a round about way to achieve this.. Since the main aim was to reduce the load on the firewall, we identifid an un used IP in the same network as the application server and added a static route to point all traffic going to the mail server to this IP. We ran the following command “route ADD IP_ADDRESS_OF_MAIL_SERVER MASK 255.255.255.255 UN_USED_IP_ADDRESS

For example, if you application server is in the range 192.168.1.0/24, the mail server is 192.168.2.20.. and an unused IP in the application server range is 192.168.1.10.. the command would look like this “route ADD 192.168.2.20 MASK 255.255.255.255 192.168.1.10“.. You will see a lot of SYN_SENT status in the network connections, since the application is trying to connect t othe mail server via an IP address that doesn’t exist..

Might not be the smartest way to achive this.. but it did the trick.

Windows 7 : Installer Issues

As posted here, I have been playing around with the Beta version of Windows 7. Everything was working great, until I started getting  a mysterious error “Installer stopped working”, when I tried to install any new software. A Google search, led me to this site (http://www.sevenforums.com/general-discussion/2349-windows-installer-cant-install-any-msi-package-4.html) . Here’s the solution to the issue. 

start regedit
navigate to HKLM\Software\Microsoft\SQMClient\Windows\DisabledSessions
rename MachineThrottling to _MachineThrottling

What does one trillian dollars get you?

If you are a Zimbabwean, it will get you USD30 worth of stuff!! Ran across this story (http://news.bbc.co.uk/2/hi/africa/7832601.stm) on BBC, about the government of Zimbabwe releasing a trillian dollar note to cope with inflation. Zimbabwe was one of the most stable and prosporous country in Africa, until Robert Mugabe, started to enforce his lunatic policies. I can never understand, why people allow such morons to rule them..

BTW, One trillion has 12 zeros in it :-).. It looks like this..

$1000000000000

I would like to get my hands on one of these notes.. just to look at it :). I tried a search on Ebay and it looks like there is an active market for the Zimbabwean currency. At least Robert Mugabe managed to make a Zimbabwean product desirable :).

Beta for the Beta

I got a copy of the Windows 7 Beta copy from my colleague and installed it on my Lenovo X61 tablet. The install went through pretty smoothly and . upon booting up the computer, me and my colleague had the following conversation..

Colleague : Thats a Beta!!

Me : Yes.. it is Beta..

Colleague : No.. No.. that”s a beta!!

Me : Dude.. seriously.. it is Beta.. I know it..

Colleague : (almost smacking me on my head) No..that is a Beta Fish!!

Looks like a smart programmer (or marketing person) put the picture of a Beta fish as the default background for Windows 7 Beta :-).. Here’s a screenshot.

Hopefully, Windows 7 will finally convince us XP lovers to upgrade. Vista is a failed operating system as far as I am concerned. Not in the league of “Windows Millenium“, but it is going to be shoved away into the annals of history soon if Windows 7 delivers as promised.

Stomach Stimulus Package

I stopped at Hippos, a hot dog place in Elk Grove for lunch today. I was using the drive through and saw this sign on the drive through window

The owner put together a combo for $15.99, which will get you a meal for 4 people. The sign reads “Feed a Family of 4 for under four bucks per person!!! Times are Tough. Hippo’s will help you get through it with our stomach stimulus package.”

After I pay for my lunch, the hostess hands me an envelope which looks like this

Simple but brilliant marketing. First connect with your customers in this tough time.. then give them an incentive to come back.  I would go back to the place to check out if I won anything.. and guess what, even if I don’t win anything, I will most probably end up getting something to eat there. I am sure this joint is going to survive

Tools of the trade : Postfix Configuration

Good link with information on configuring a custom transport link in Postfix. A transport link in a SMTP server is a way to define a communiction/delivery channel with particular settings. Example, you want all e-mails for a particular domain to be sent to a particular server at a particular time.

http://linuxnet.ca/postfix/dedicated_transport.html

In this particular link, the author shows the steps to configure a transport link for sending e-mails to servers/domains with high latency.

Visual outlook of Kudithipudi.org

I ran across an interesting app called Wordle, that the BBC news service, used to show a visual representation of all the words president Bush used in his state of Union speeches (http://news.bbc.co.uk/2/hi/americas/7813432.stm).

Wordle (http://www.wordle.net/) take text or a URL as input and automatically generates a visual representation of the text based on the number of times a term appears. Very cool application of Web 2.0  technology.

Here’s how this website looks after wordle analyzed it.

Wordle is a “toy” created by Jonathan Feinberg. Here is a good interview with him regdarding Wordle and how he created it (http://domino.research.ibm.com/comm/research.nsf/pages/d.compsci.can_i_have_a_wordle_with_you.html).