Sergei Home Blog

Business Case Studies

2010-09-24T16:54:00.001-07:00

http://guides.lib.uchicago.edu/case_studies

Awesome cartoons

2010-08-30T21:19:00.001-07:00

http://www.youtube.com/user/theRSAorg

Save Money with Amazon Coupons

2010-05-24T17:02:00.000-07:00

Wouldn't it be great to get fashion items, kitchen equipment or even gardening tools at reduced prices any time you wanted, instead of having to wait for those closeout or clearance sales? Well you can now with a little insight, and more importantly innovations brought to you by www.azPriceWatch.com who have constantly seek out and publish a variety of amazon coupons in various different categories, to save you money.

Coupons from azPriceWatch.com range from food item coupons, such as the range of Taco Bell food products (Use TACOBEL5) to that of 15 to 30% off of diamond and emerald nuts, the choices are extensive! Visit http://www.azpricewatch.com/Amazon/Coupons for their extensive range of Amazon Coupons.

Simple online RegEx Testing tool

2009-12-29T14:00:00.001-08:00

http://derekslager.com/blog/posts/2007/09/a-better-dotnet-regular-expression-tester.ashx

Creating Custom State Activities in WF 3.5

2009-12-16T09:02:00.000-08:00

Hi there.
Recently ran into the task to create custom state activities for Microsoft Workflow Foundation and it appears to be not simple as expected.
Here are couple links that can drive you in the right direction:

First one: Why are there no 'composite state activities'?

http://social.msdn.microsoft.com/forums/en-US/windowsworkflowfoundation/thread/e0af5e93-15df-473e-8573-fb0846a38cb6/

http://doogalbellend.blogspot.com/2007/11/developing-custom-state-activities.html

Storing variables in XOML Workflows
http://doogalbellend.blogspot.com/2008/02/storing-variables-in-xoml-workflow.html

Is Singleton in .Net always single?

2009-12-06T11:40:00.000-08:00

Just ran into unusual scenario - couple appdomains, dynamic assembly loading and a singleton class defined in one of the assemblies.
You would expect singleton to have only one instance, right?

Well, not really. Singleton was defined in a library that was referenced by the executing app and the app is loading the same library into the separate app domain. So we end up with one app, 2 app domains and 2 instances of the same assembly loaded into separate app domains.

So calls to the singleton occur from 2 different app domains and it should be expected from singleton to have only one instance. Right? Well... Reality is different from theory. We end up with 2 (two) instances of the singleton in the same app. Really inconvenient.

The solution was to define singleton in the base assembly that is referenced by the main class library.. In this case we are having only one instance of the assembly loaded in the app and hence only one singleton.

This leads to 3 conclusions:
1 - Expect unexpected
2 - AppDomains can REALLY be used as great isolation blocks
3 - Actually, there are implementations of cross app domains singletons, which can be used in a case when you need one to be really shared among different app domains and possibly even multiple apps

Serialization in .Net.. Google still ahead?

2009-11-30T20:24:00.000-08:00

Hello,
Just took a look at potobuf - 'serialization' protocol from google.
Here are performance test results from google (using 2 different protobuf libraies for .Net):

http://code.google.com/p/protobuf-net/wiki/Performance

And links to the libraries:
Protbuf-Net
http://code.google.com/p/protobuf-net/
And Proto#:
http://code.google.com/p/protosharp/

And other 3rd-party add-ons for protocol buffers:
http://code.google.com/p/protobuf/wiki/ThirdPartyAddOns

P.S. Can't wait to try it in my own projects.

Best!
Sergei

ASP.NET 2.0 Tips, Tricks, Recipes and Gotchas

2009-11-30T15:08:00.000-08:00

Couple more great links for ASP.NET developers:
ASP.NET How do I videos:
http://www.asp.net/learn/

And great ASP.NET 2.0 Tips, Tricks, Recipes and Gotchas from ScottGu Blog:
http://weblogs.asp.net/scottgu/pages/ASP.NET-2.0-Tips_2C00_-Tricks_2C00_-Recipes-and-Gotchas.aspx

WCF 3.5 articles on Events, Interprocess Communication, Named Pipes

2009-11-04T12:40:00.000-08:00

http://www.switchonthecode.com/tutorials/wcf-tutorial-events-and-callbacks

http://www.switchonthecode.com/tutorials/wcf-tutorial-basic-interprocess-communication

http://www.switchonthecode.com/tutorials/dotnet-35-adds-named-pipes-support

MS SQL 2005 Rank functions

2009-11-04T00:08:00.000-08:00

Pretty interesting MS SQL 2005 functionality.
Here we go:
Ranking functions in MS SQL 2005
http://go4sqlserver.blogspot.com/2009/07/ranking-functions-in-sql-server-2005.html

And one more good example
http://www.kodyaz.com/articles/tsql-dense-rank-function.aspx

Simple and easy to comprehend slides on MS .Net Technologies

2009-11-02T14:42:00.000-08:00

Right here:

Simple and easy to comprehend slides on MS .Net Technologies

LINQ to Objects in 5 minutes - concentrated and no BS

2009-10-26T10:18:00.000-07:00

Just found excellent short articles on LINQ -
LINQ to Objects in 5 minutes:
http://www.hookedonlinq.com/LINQtoObjects5MinuteOverview.ashx

They also have:
LINQ to SQL

LINQ to XML

Writing LINQ Queries

Know better Linq tutorials? - Share!

P.S. One more:
101 LINQ Samples from Microsoft

San Francisco Small Business events

2009-10-24T13:00:00.001-07:00

http://sbatraining.eventbrite.com/

Microsoft .Net University - worth checking out

2009-10-16T14:35:00.000-07:00

While looking to refresh my knowledge on Microsoft .Net technologies I found this
http://dotnet-u.com/Courses.aspx website. It is full of free courses, slides and labs on various .Net technologies like WCF, WPF, BizTalk, SharePoint, ASP.NET, ASP.NET MVC, LINQ, Silverlight and even Silverlight + Twitter.
Take a look

Books I want to read

2009-10-09T07:38:00.000-07:00

Here is the list of books that were recommended to me by my closest friends.
Most of them are about business, success, etc.
Let me know if you find something is interesting for you, and don't forget to share the best books you ever read

The Google Story: Inside the Hottest Business, Media, and Technology Success of Our Time
Think Like a Champion: An Informal Education In Business and Life
Think Big: Make It Happen in Business and Life
The Paradox of Choice: Why More Is Less
Stumbling on Happiness
The Diary of a Young Girl by Anne Frank

Paradox of choice

2009-10-09T06:02:00.000-07:00

Awesome talk by Barry Schwartz on the paradox of choice.
http://www.ted.com/index.php/talks/barry_schwartz_on_the_paradox_of_choice.html
What he is saying is that more choice makes the decision making person uncomfortable and to delay the decision to later times.

Visual C# highlights on MSDN

2009-08-15T15:06:00.001-07:00

Visual C# highlights on MSDN:
Here it is:
http://msdn.microsoft.com/en-us/vcsharp/default.aspx

Amazon daily deals - launched!

2009-08-07T12:04:00.001-07:00

Announcement! www.azdailydeals.com is launched.

You can find bease amazon deals on tools, apparel, clothes, kitchen and beauty appliances and much much more.
http://azdailydeals.com/amazon/bargains/Top-Deals-3-Days/ - top 3 days deals(hurry up - can be sold out!)
http://azdailydeals.com/amazon/deals/Kitchen/ - best amazon kitchen deals
and http://azdailydeals.com/amazon/deals/Beauty/ - best beauty and cosmetics deals

Let us know what you think, what you like and what else we can do for you.

Never pay a face price

2009-06-19T17:41:00.000-07:00

Hello!
Just want to write couple words about newly discovered website - www.azPriceWatch.com. That one helps you to find savings on the amazon.com. How to use it - just go there, select a category and see items with recently decreased prices. You can also use froogle.com (tool from google) to research the price for the item. Why amazon.com? Simply because prices there fluctuate a lot, and by choosing right time to buy you can actually get better value for your money.

Cheers!
Sergei

Excellent and simple articles on MS SQL Indexes and Execution Plans

2009-06-10T13:22:00.000-07:00

Hi,
I've recently got involved in pretty unusual task for me - troubleshooting DB performance and optimizing database queries.
And while looking for information (read using www.google.com) I found this simple and clear article: SQL Server Indexes
It discusses and compares performance of:
Clustered Indexes
Non-Clustered Indexes
Using covering indexed
Benefits of using columns specified in index
Using "Or" in WHERE statements

Read and enjoy!
Again, the URL is SQL Server Indexes

Sergei

P.S. Couple more links on indexes and execution plans:
Index Optimization Tips
Execution Plan Basics

Couple useful MS SQL stored procs and commands

2009-05-01T14:41:00.000-07:00

Here are couple useful build-in stored procedures:

To determine the name and the current location of all files that a database uses:
use
go
sp_helpfile
go

To determine processes and queries running on a server:
sp_who2

To determine locks on the server:
sp_lock

To kill process:
kill #SPID
You can get #SPID from sp_lock or sp_who2 output

To see the ast statement sent by the client to the instance of the SQL server:
DBCC INPUTBUFFER(#SESSION_ID)
#SESSION_ID is the same as #SPID

To list all active session on the server:
select * from sys.dm_exec_sessions
To list all active connections on the server:
select * from sys.dm_exec_connections

Feel free to comment and share your favorite tools to troubleshoot MS SQL server.
Sergei

The most useful list of DateTime.ToString parameters

2009-04-30T06:56:00.001-07:00

Here we go:
http://authors.aspalliance.com/aspxtreme/sys/demos/datetimeformats.aspx

Network tools - sniffers for Network/WCF/Web services programmers

2009-04-15T07:14:00.000-07:00

Hello there,
Just want to share couple links to my favorite tools for monitoring network traffic. I usualy use them when need to figure out what's going on on the wire when doing some WCF/Web services programming and things does not go the intended way. Feel free to share your own favorite tools!

TCPTrace
Simple but very effective - this tool allows you to see TCP/HTTP traffics, redirect and and can act as a proxy for a selected port. Very lightweight and simple.
http://www.tcptrace.org/

WireShark (Formely known as Ethereal)
Very powerful tool, allows youto select network adapters, ports, set up complex filtering and analysis. Little bit more complex to use though then TCPTrace
http://www.wireshark.org/

Sergei

Sending emails from .Net 2/3/3.5+

2009-03-06T08:55:00.000-08:00

Hello there,
Just spent some time analysing the best and most convieniet ways to send email with file attachment from .Net apps. The question was how to send emails with attachments from files AND Streams - for example when we have text or data in memory, and don't want to save it to the disk because of security, disk or other settings or limitations.

After review of

FreeSMTP.Net
EasyMail .Net Edition
Chilkat Mail
MailBee.NET SMTP
Native .Net 2.0+ functionality

I've figured out that actually the easiest(and free) way is to use System.Net.Mail classes - they are simple, easy to use and understand, and provide all functionality for basic and advanced needs.

Looks like 'components for purchase' were created when the only one available native way of sending emails in .Net 1.0/1.1 was System.Web.Mail - and it was inconvinient, limited and unreliable.

Microsoft reworked it and the result is awesome.

Here is the link to extremely easy to read and understand guide to the System.Net.Mail classes: http://www.systemnetmail.com/

P.S. Found one interesting thing - if you have Symantec antivirus installed on your machine it can block outgoing emails which are send by your local .Net applications.

Cheers,
Sergei