Scalability using Network Load Balancing (NLB)

By using a load balancer setup, a load can be shared across multiple Winshuttle SERVERS. Sharing the load increases the concurrent requests that can be processed.

How NLB works

1. Multiple clients connect to Winshuttle SERVERS, but each client is exposed to only the load balancer IP (VIP).
2. A client sends a request to a Winshuttle SERVER through the Load Balancer.
3. The load balancer forwards the request to one of the Winshuttle SERVER machines, based on the configuration of the Load Balancer.
4. The request is processed by Winshuttle Server and sent back to the client.

Workflow in a network load balancing deployment

The database is shared across multiple Winshuttle SERVER computers. Suggested databases include

• Microsoft SQL Express
• Microsoft SQL Server 2005 or Microsoft SQL 2008

All the Winshuttle SERVER computers support all the available Winshuttle products and features. In other words, Winshuttle SERVER computers are not dedicated to specific tasks, such as Server1 for QUERY.

1. To create the necessary tables in the database, execute the appropriate database script. If you used the SERVER data migration utility to upgrade to version 10.4, the script has already run. If you use a separate cache database
2. Open the Winshuttle SERVER web.config file and enter the valid connection string for the database. To get the correct Connection String, you may need to ask your Database Administrator. The following is an example of a connection string:

   connectionString="Server=\SQLExpress;database=WinshuttleServerDB;Integrated Security=SSPI;" type="MSSQL2008"

3. For each server installed under the load balancer, the web.config file points to the same database and thus contains the same connection string.

   connectionString="Server=\SQLExpress;database=WinshuttleServerDB;Integrated Security=SSPI;" type="MSSQL2008"

Important

• All web config changes must be made in all backend servers.
• All IIS related changes, such as configuring the SSL limit and iisreset, must be made on all backend servers.
• The recommended databases are SQL Server 2005 or SQL Server 2008.
• Memory caching is not supported with network load balancing.
• If launch GUI and SSO are used, these features must be configured on all backend servers.
• In Winshuttle CENTRAL Administration, under SERVER, click TRANSACTION or QUERY Server Configuration, and then type in the IP address for the loading balancing server.