Transactions in .NET 2.0

After procrastinating the installation of VS .NET 2005 beta 2 for almost a week now .. I finally got it installed and running on my laptop..

The first thing that caught my attention is the revised Transaction support. .Net v1.1 supported two transaction programming models.. explicit transaction programming model (using IDbTransaction interface) and Declarative transaction flow model(using System.EnterpriseServices). The explicit programming model cannot be used when you have distributed transactions. But the Declarative transaction comes with the price of COM+ hosting model which many Configuration Managers find intimidating ;). and it has the overhead of using DTC transaction even though only a single resource is involved. So there is no clean and easy way of transaction management in .Net 1.1.

.Net 2.0 addresses all the above issues with the addition of two new transaction managers Lightweight Transaction Manager LTM(similar to .Net 1.1 explicit programming model) and OleTx Transaction Manager OTM(Similar to .Net 1.1 Enterprise Services) and helper classes available in System.Transaction namespace. As developers we need to be aware only about the usage of System.Transaction namespace and .NET internally takes care of using the appropriate resource manager.

Suppose a object is accessing only a single durable resource(SQL server 2005) .NET would use LTM internally to provide the best throughput and performance. If at any point the object accesses another durable resource(MSMQ) then the transaction will automatically be promoted to use OTM. This transaction will remain in this state till its completion.

A simple usage of TransactionScope:

using(TransactionScope ts = new TransactionScope())
{
// do any transactional work here
// The transactional work could be spanning one resource or multiple resource.
// calling complete will commit the work.
ts .Complete();
}

Make sure to call the Complete() method or else your transaction will be rolled back..

One important thing worth noting is the existing enterprise services like Oracle, SQL server 2000 and MSMQ cannot participate in an LTM transaction. So by default they use only the OTM manager.

Difference between Hashing & Encryption

Many people tend to think of Encryption & Hashing being one and the same :(

Encryption and hashing are completely different. With encryption, you have the ability to decrypt. Its usage is like a you encrypt the text, you will be able to decrypt, whether it is with one symmetrical key or with a pair of keys.
Hashing is a one-way function. When you hash a value, you are always guaranteed to get a certain result. But with that result, you will not be able to reverse it and retrieve the clear-text. Also with hashing, the size of the hashed data will always be a certain sized specified by the hashing algorithm.

When to use encryption versus hashing depends on the application. Hashing is fast and only one-way. That's the key difference. One-way versus Two-way.

Free Wireless Internet

I booted my new laptop with the inbuilt wireless in my house last night ... to my surprise i had too many unsecured wireless network available for me to choose... I think there are too many people out there who dont have enough idea of how to go about setting up a secure wireless network... I am not a networking/wireless guru nor I haven't setup a wireless network of my own yet.. but I was googling around for the steps to make a wi-fi secure.

• Change the default SSID. Most people don't even bother to change the default SSID provided by a wireless access point. If your neighbor knows that you are using a Linksys wireless access point (say, by seeing the boxes you throw away), they could easily try the default SSID. Always change the SSID to something obscure, and never try to use your company name or your personal name. These names are too easy to guess.
  Disable SSID broadcast. By default, most wireless access points will broadcast the SSID to all wireless devices; anyone with a wireless network card can detect the SSID you use in your network and gain access to your network.
• Use MAC address filtering. If you have a small number of users in your wireless network (which is usually the case), you can use MAC address filtering. With MAC address filtering, you enter the MAC address of your network card and manually enter this number into your wireless access point. Only MAC addresses that have been registered with the wireless access point are able to gain access to your network. You can usually locate the MAC address of your network card on the device itself.
• Always change the default user name and password for your wireless access point. It's too easy for people to guess the default user names and passwords used in wireless access points.
• Turn off DHCP. Use static IP addresses if the number of users on the network is small. Turning off DHCP will prevent wireless sniffers from seeing the IP addresses being used.
  Refrain from using the default IP subnet. Most wireless routers use the default 192.168.1.0 network. It is easy for people to guess the IP addresses used and illegally gain access to the network.
• Use WEP for encryption of packets. If you are concerned about the confidentiality of information transmitted by your wireless network, you may wish to enable WEP encryption. Though WEP has been proven to be "crackable," it still acts as a deterrent against packet sniffing for everyone but ardent hackers.

New Laptop

I got my laptop delievered from DELL today .. It's Inspiron 700M model with Intel Pentium M 1.6 Ghz processor, 1 GB SDRam, 80 GB Hard disk drive, 8X CD/DVD burner and integrated 802.11 b/g wireless .. I made sure I am getting the latest configuration b'cos it will be really expensive to upgrade these laptops if needed in the future..

I went down my memory lane and the year was 1995.. second year in my college when my dad decided to buy me a computer.. He got the latest configuration for me then... an Intel 486 processor with 4 MB Ram and 512 MB Hard Disk Drive and had a 1.44 Floppy Disk Drive... I am just amazed by how fast things have changed in the last 10 years.. My new laptop has RAM twice the size of my old Hard disk drive, even a CD drive was an expensive thing in the past and now I have a CD/DVD burner. Floppy Disk Drive have become totally absolute. Even modem is not a common thing when you buy a computer.. nowadays we have gone from wired - wireless modems..

I cant even imagine what's going to happen 10 yrs from now.. But I am sure we will have computers with 80 GB RAM ...

Toilet Paper and Thread Synchronization

I am sure anyone reading this post to see the wierd title. what does Toilet Paper has anything to do with Thread Synchronization??? Mike Woodring has used Toilet Paper as an analogy to teach people about Thread Synchronization.. and he does it pretty well. take a look at this article and I am sure you will appreciate it :)

http://pluralsight.com/blogs/mike/archive/2004/12/13/3905.aspx

What movie are you ??

I just came across this link "what movie are u ?? ".. found it interesting and thought will try it.. and this is my result. But not sure whether I answered all my questions correclty ;)

What Classic Movie Are You?
personality tests by similarminds.com

Wanna write a Computer book.

One of my long time goal is to write a technical book... (something like "Programming .Net components" by Juwal lowy.. I know I am trying to set too high a standard here.. but there's nothing wrong in aiming for the star :) ..

I was not sure the things I need to develop to write my own book... I was lucky to read this article written by Eric Gunnerson .. read this article if you aspire to become an author someday..
http://blogs.msdn.com/ericgu/articles/396328.aspx

Good Books on C#

One of my friend called me y'day to get information about some good books on .Net/C# (currently working in VB and wants to move to .Net). I have always suggested "Programming .NET components" by Juval Lowy to almost anyone who is interested to get into C#. It's one of the few books out there which doesnt re-hash MSDN ;) The book is well organized and the writing style of the author is excellent. But the book is meant for developers who have knowledge of OOPS and is looking forward to get thier hands dirty on .NET with C#. The examples given in the book might not be from real life applications.. but will certainly make the underlying concept clear.

Juval Lowy is a class apart from most instructors/architects available for .Net/C#. I think that's the reason he has been crowned as one of the "Software Legends" by Microsoft.
I was reading a blog the other day that he is currently working on the second version of the above mentioned book... Let me keep my fingers crossed to see when it hits the stores... I will be one of many who would like to get a copy of the book first day :)

Improving Software Development Process using VS 2005

I have always thought that Microsoft was not doing enough for improving the Software Development Process. Visual SourceSafe the flagship product offered by them is not a very good one.. I have been hearing stories about the VSS Database getting corrupted. Currently, we use PVCS Version Manager as the Sourcesafe repository. It seems to be doing a pretty good job but I should say that the User Interface is slow & hard to use.. ( I can't expect more from an application written in Java :)

Also, Microsoft doesnt have a product similar to PVCS Tracker(tool for creating SCR- Software Change Request and easily integrates into Version Manager to associate a file to a particular SCR.)

I think my long wait might be over with the release of VS 2005.. It's going to offer tools like Work Item tracking, Unit & Load testing, Managed Code Analysis and integrated Source control (Team Foundation). Most of these features are already available to us.. but having them integrated into VS will be coool... There seems to be quite a lot of features that will help a software team to work more efficiently. But I am sure MS is gonna charge quite a lot for people who want to upgrade from VS 2003 to VS 2005...

When you get some time, take a peek at the following article written by Chris Menegay about the upcoming improvements in VS 2005.

http://msdn.microsoft.com/msdnmag/issues/05/04/TeamSystem/default.aspx

Mailinator/BugMeNot

I just came across couple of cool sites

• Mailinator (www.mailinator.com) It's a no signup, anti-spam service. Here's how it works : You are on the web and someone (website) asks for your email id.. and there is a chance they might be selling your email id to spammers. Just go to mailignator and create a temporary account (remember you dont have to go thru a rigorous process of signup, personal infromation) and give that id. Go back to Mailinator and use this id to check the mails.. pretty cool.. kind of use and throw email ids :). But I think some websites have already started disallowing the entry of @mailinator for the email id..
• BugmeNot (www.bugmenot.com) You must have come across million of websites asking to enter username/password to access thier content( ex. www.nytimes.com) Most of the time I dont want to register to these sites... (alright !! I am LAZY/ scared that my email id will be sold to some spammer)... If you are someone like me then bugmenot is for you...Point your browser to bugmenot and enter the name of the website and you will be given a username/password to the website.. :)

These websites are going to stay in my favourite folder for a long time..