"Cannot connect to Configuration database " error in sharepoint 2010

This behavior occurs if one of the following conditions is true:

• The SQL database is not running.
• Internet Information Services (IIS) is configured to run in IIS 5.0 isolation mode.
• The account that is used by application pool does not have the required permissions to the SQL Server database.
• Network connectivity has been lost between the Windows SharePoint Services server and the Microsoft SQL Server server.

Method 1: Verify that the SQL database is running

1. Click Start, point to Programs, point to Administrative Tools, and then click Services.
2. In the list of services, locate the MSSQLSERVER service. This service may also be listed as MSSQL$SHAREPOINT.
3. Note the value of the Status column. If the Status column lists Started, the database server is running. If the Status column is empty, the database server is not running.
   
   To start the database server, right-click the MSSQLSERVER service, and then click Start.

Method 2: Verify that IIS is not running in IIS 5.0 isolation mode

1. Click Start, point to Programs, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
2. In the left pane, right-click your server name, and then expand the local computer.
3. Right click Web Sites, and then click Properties.
4. Click the Service tab.
5. Click to clear the Run WWW service in IIS 5.0 isolation mode check box.
6. Click OK
7. To start the WWW service, click Yes.

Method 3: Make sure that the account that is used by the application pool is the account that has the required permissions to the SQL Server database

First, you must first determine the application pool identity. To do this, follow these steps:

1. Click Start, point to Programs, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
2. Double-click the Web Sites folder.
3. Right-click the virtual server that is running Windows SharePoint Services 2.0, and then click Properties.
4. Click Home Directory.
5. Note the information that is in the Application name box (this is the application pool name), and then click Cancel.
6. In the left pane, right-click Application Pools, and then click Properties.
7. Click the Identity tab.
8. Note the information that is in the Application pool identitypane, and then click Cancel.

Next, you must verify that this account has the required permission the SQL Server database. To do this, follow these steps:

1. Click Start, point to Programs, point to Microsoft SQL Server, and then click Enterprise Manager.
2. In the left pane, double-click Microsoft SQL Servers, and then double-click your SQL server group.
3. Double-click your server.
4. Double-click Security.
5. In the left pane, click Logins.
6. In the right pane, double-click the user who you noted step 8 of the previous procedure.
7. In the SQL Server Login Properties dialog box, click Server Roles.
8. Click to select both the Security Administrators and the Database Creators check boxes, and then click Database Access.
9. Under the Permit column, click to select the Windows SharePoint Services database.
10. Click OK.

Method 4: Make sure that you have network connectivity and correct name resolution between the servers

To do this, follow these steps:

1. Verify that the Windows SharePoint Services server is using the correct IP address for the SQL server. To do this, run the ping command on the Windows SharePoint Services server.
2. Verify that the Windows SharePoint Services server is obtaining the correct IP address for the SQL server from DNS. To do this, run the nslookup command from the Windows SharePoint Services server.
3. Make sure that there are no incorrect entries for the SQL server. To do this, examine the Hosts file on the Windows SharePoint Services server. This file is in the following location:
   %systemroot%\system32\drivers\etc\Hosts
4. On the Windows SharePoint Services server, look for SQL client aliases. To do this, follow these steps:
   1. Click Start, click Run, and then type cliconfg in the Open box.
   2. Click the Alias tab.
   By default, there are no SQL client aliases. If you have any aliases for the SQL server, verify that they are correct, or remove them.

Selenium

Introduction: 

Selenium is a suite of tools for browser automation. It is composed of 
"IDE", a recording and playback mechanism, "WebDriver" and Remote 
Control "RC" which provide APIs for browser automation in a wide variety
 of languages, and "Grid", which allows many tests using the APIs to be 
run in parallel. QA Tester should not forget to mention during interview
 that with the release of Selenium 2, Selenium RC has been officially 
deprecated in favor of Selenium WebDriver. It works with most browsers, 
including Firefox from 3.0 up to 8, Internet Explorer 8, Google Chrome, 
Safari and Opera 11.5.

 Selenium could be used for the functional, regression, load testing of 
the web based applications. 

 Advantages & Features of Selenium 

1.Intelligent field selection will use IDs, names, or XPath as needed 
2. It is a record & playback tool and the script format can be written in
various languages including : C#, Java, PERL, Python, PHP, HTML 
3. Auto complete for all common Selenium commands 
4. Debug and set breakpoints 
5. Option to automatically assert the title of every page 
6. Support for Selenium user-extensions.js file

Selenium Limitations 

 Selenium IDE has many great features and is a fruitful and 
well-organized test automation tool for developing test cases, in the 
same time Selenium IDE is missing certain vital features of a testing 
tool: conditional statements, loops, logging functionality, exception 
handling, reporting functionality, database testing, re-execution of 
failed tests and screenshots taking capability. Selenium IDE doesn't for
 IE, Safari and Opera browsers.