Cloud Computing

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What is cloud computing ? Before getting into the term what is cloud computing ask a question to yourself whether you have experiences working in the cloud. Every day we deal with cloud computing and use it. But the matter is we don’t know that is the cloud computing. The buzz cloud computing was a hot topic in 2007 and 2008. And still plenty of researches and business analyses are going in cloud computing.

Cloud computing is nothing other than using websites and web services for our use. Use in the sense it can be personal,business oriented or any thing else. Simply Facebook provides you a service of social networking. You save photos, videos and your notes in your accounts. You access them whenever you have an Internet connection. So the availability of the resources is high. Your share documents in the Skydrive, again whenever you have the access to Internet you have the access to your documents. And recently the Microsoft started the Office Web App. So the resources you saved and shared float above you like a cloud. Whenever you need them, you access it through the Internet. So cloud computing is not new to us and it is not other than the Internet computing and web services.

There are some buzz stories why we use the term cloud. One is most of the places and text books a cloud symbol is used to represent the Internet. So some say that’s the reason we call it cloud computing. Another story is the resources and the services you need, just float there and available every where like a cloud, and you can access it whenever you want it. Some say this is the reason how the word cloud came. But personally I prefer the 2nd one since it is more reasonable than the first one.

When it comes to cloud it has plenty of advantages

  • Hardware and Software independent. (You just need a machine with Internet connection)
  • High availability of the applications
  • The companies need not to worry about the Server farm requirements
  • Very cost effective
  • And much more..

Please do not get confused between the web hosting and the Cloud computing. Web hosting is getting a domain name from a hosting company and pay the company, then your site is up there in the Internet. Cloud is hosting of course but differs from the normal hosting. When it comes to cloud computing it is a platform and a development environment but a normal hosting doesn’t have those features.

Cloud application provides more scalability for the applications, managing, configuring and much more. Apart from that cloud does not include only web pages (web pages work as front end for the application / service).

Understanding the cloud computing is simple and easy. One simple googling on cloud computing will fetch you thousands of resources.

SQL Server Protocols

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Based on some missing images this document might appear in a broken flow

SQL Server is the Microsoft’s Enterprise Data Management system. Recent release is SQL Server 2008 R2 (x64 bit only). We all know about the Database Management System and Database related concepts.
SQL Server comes with two powerful tools SQL Server Management Studio and SQL Server Configuration Manager.

To start learning SQL Server 2008 you should have an instance of database engine. Install it and connect to using SQL Server Management Studio.

To connect to the default instance type (local) or . (a dot) or server name. In your local machine the server name would be your machine’s name, in my case Thurupathan-PC or type localhost Typically you can specify the <server name>/<instance name>. If you do not provide the instance name it will connect to the default instance.

The parameters you can specify as server are

  • (local) – to connect to the local default instance
  • . – to connect to the default instance
  • localhost – to your local machine to default instance (Thurupathan-PC also same)
  • server name/instance name (ex – Thurupathan-PC/Sharepoint)

Here server is the physical (or a virtual ) machine. You can install more than one instance of database engine in one server.

You are connected to the default instance. Download the Adventure Works 2008 database from http://www.codeplex.com . This comes as a .msi file you can just double click it to install. (I didn’t explain the Restore Database process here for older Adventure works scripts, but I’ll explain restoring the database using another example). You do need to have the adventure works database in order to do the following exercise.

Then you are done with the learning track of the SQL Server 2008 or SQL Server 2008 R2.

Here I do not explain from the very beginning SELECT statements as you can Google for plenty of SQL statement tutorials. I explain only some specific things related to SQL Server configurations.

SQL Server runs on top of SQL Server OS which runs on a Windows OS. It has four protocols to connect with the database engine. You can view them through the SQL Server Configuration Manager.

MS SQL Server uses the port 1433 as its default port.

The default MSSQLSERVER instance can be configured with 4 different protocols.

  • Shared Memory – This protocols is used to run the server in the local machine.(You can right click and make it enable and disable)
  • Named Pipes – This used serve the machines in the local network. (typically in a specific broadcasting domain)
  • TCP/IP – This TCP/IP as we all know used to connect over the Internet, beyond a single broadcasting domain.
  • VIA – Virtual Interface Adapter is used to connect machines using specific machines by specifying the NIC number. This is also used to make transactions with different Database management systems.(I’m searching for some good explanation for VIA)

You can get a question that if Shared Memory, Named Pipes and TCP/IP are enabled which will be used for a connection. The Shared Memory cannot gain access to an external machine so no need to talk about that.

If the server and the client are in a single broadcasting domain what will be used ? Named Pipes or TCP/IP. It is based on which order the protocols are configured. You can change the order by switching to the SQL Native Client 10.0 Configuration and Client Protocols.Named Pipes are typically faster than the TCP/IP.

And Finally by executing this query (in SQL Server Management Studio) you can view the currently used protocol. (After executing in your local machine you’ll get the Shared Memory as result)

SELECT net_transport FROM sys.dm_exec_connections WHERE session_id = @@SPID;

You can disable various protocols and try to the above query to get different results. (If you are enabling or disabling the protocols you should have to disconnect from the instance and restart the service to take effect)