What stateless and stateful load balancing?

Sql server Interview Questions :What is the stateless and stateful load balancing?
Stateless load balancer
Stateless load balancer uses the hashing algorithm. It takes packet from the client and selects fields from the packet to be hashed. For instance from each client it can take IP address and port number and hash them in to an integer between 1 to number of servers. You can see from the figure we have four servers. So the load balancer takes the IP address and port and hashes them with a number between 1 to 4. Depending on the number the client is directed to the server. For instance client A is directed to server 2, client b to server 1 and so on. Once the client is connected to a server it is always redirected to the same server.
Figure: - Stateless load balancing
Advantage of stateless load balancing is that it’s simple. The biggest disadvantage is that it treats all clients equally and connects one client to one server always. That is if client A is connects to server 2 it will always connect to server 2. This is irrespective of how many times client A sends request. So if client A sends 100 request and client B sends 10 requests even then client will be sent to server 2 for all the 100 request and client B to server 1 for all requests.

Stateful load balancer
In stateful balancing the load balancer looks at each session and assigns it to the appropriate server based on load. In order that the load balancer can track each session it needs to know when the session starts and when it ends.

Figure: - Stateful load balancing

You can see from the figure for every session the load balancer redirects the request to different servers.

Architecture of Notification Services?

Sql server Interview Question : Explain Architecture of Notification Services?
Detail sections in SQL notification services:-

Notification Service application: - It’s a simple user application which will be used to add subscription to the subscription database.

Event providers: - All events reside in Event providers. There are two event providers which are provided by default “File System watcher” and “SQL Server event provider”. “File System watcher” detects changes in operating system files. “SQL Server event provider” watches for SQL Server or analysis service database for change. You can also plug in custom event providers. When event providers find any change in database, they send the event in “Event” table.

Generator: - Generator checks the event database, when it finds any event it tries to match with the subscription and sends it to the notification database. So generator in short is the decision maker between the subscribers and the events.

Distributor: - Distributor continuously pools the “Notification” database for any “Notification’s” to be processed. If the distributor finds any entry, it retrieves it and formats it so that it can be delivered to the end recipient. Formatting is normally done using “XML” and “XSLT” for rendering purpose.

After the formatting is done, it is then pushed to the “distribution providers”. They are nothing but medium of delivery. There are three built-in providers:-

• SMTP provider
• File provider
• HTTP provider
• Figure: - Detail architecture of SQL notification services.

SQL Server interview questions

SQL Server interview questions
1)Explain architecture of Notification Services?
2)What is the stateless and stateful load balancing?
3)What do you mean about Fragmentation in SQL Server?
4)Explain two types of indexes?
5)What do you mean by State publisher, distributor and subscriber in “Replication”?
6)Different types of relationship existing in database designing?
7)How do we connect to SQL SERVER, which namespace do we use?
8)What is meant by Referential Integrity in SQL Server?
9)How to convert a Table Data in to XML format in SQL Server?
10)State the term SQL injection in SQL Server?
11)What is ACID fundamental? What are transactions in SQL SERVER?
12)What are the different types of replication supported by SQL SERVER?
13)How you can find the age of an Employee whose age is greater than 30?
14)How to back-up SQL Server Database and Restore Database?
15)Describe DBCC?
16)What is Normalization and its different forms?
17)What are the differences between INNER JOIN, LEFT JOIN and RIGHT JOIN in SQL Server?
18)What is the difference between unique key and primary key?
19)Select record with the second lowest value from the below customer table?

WepIndia Interview Questions on ASP.Net ,VB,SQL swerver

ASP.NET
1) Difference between Server.Transfer and Response.Redirect?
2) Directives in .NET? - (Page directive & Error Directive)
3) Explain about Web.Config file?
4) How many web.config file can be used with an application?
5) Page level tracing and application level tracing?
6) Explain about ViewState and what will happen if view state is false?
7) Explain about Data view?
8.What is Ispostback?
9) Use of data grid and its major properties?
10) How dataset differ from data reader?
11) How to implement polymorphisms in .NET?
12) Explain about the use of Ctype and its Syntax?
13) What is shared functions?
14) How to create xml using Dataset?
15) Explain about Global Assembly cache?
16) Where the compiled dll file stored?
17) Explain about garbage collectors?
18) How to register shared assembly?
19) Optional parameters in .NET?
VB6
1) How to create exe for vb application?
2) Early binding and late binding?
3) What is the use of option explicit and where to specify?
4) Cursor types and Lock types used with VB6?
5) How to transfer record set values to an array?
6) How to create xml file from recordset?
7) How to track errors in vb6?
What is the different between OnErrorResume and OnErrorResumeNext
9) How to register ActiveX controls?
10) What is the different between dll and ocx control?
11) How to call an exe from vb6? ie using shell scripting
12) How to pass parameter to exe?
13) How to make a connection with database using code?
14) How to specify optional parameters in VB6?
15) How to specify password field?
SQL Server 2000
1) What are cursors?
2) What are triggers?
3) How to specify parameters in a stored procedure?
4) Marks of the students are stored in a table called marks.
How to find the row containing the second largest mark from the table using sql query?