Web Garden in IIS.

A web garden is a scenario where a site is configured to run within multiple processes on a single server. You can still have multiple servers configured in a web farm, but the web garden reflects configuration of a specific individual server

When we are talking about requesting processing within IIS, Worker Process (w3wp.exe) takes care of all of these. Worker Process runs the ASP.NET application in IIS. All the ASP.NET functionality inside IIS runs under the scope of worker process. Worker Process is responsible for handling all kinds of request, response, session data, cache data. Application Pool is the container of worker process. Application pool is used to separate sets of IIS worker processes and enables a better security, reliability, and availability for any web application.

Now, by default, each and every Application pool contains a single worker process. Application which contains the multiple worker process is called “Web Garden”. Below is the typical diagram for a web garden application.

In the above diagram, you can see one of the applications containing the multiple worker processes, which is now a web garden.

So, a Web application hosted on multiple servers and access based on the load on servers is called Web Farms and when a single application pool contains multiple Worker processes, it is called a web garden.

By default a new application pool in Microsoft Internet Information Services (IIS) will run in a single process on the server. There is an option though to change the Maximum Worker Processes value to a number higher than one. When this is done, multiple processes (w3wp.exe) will spin up and serve requests made to that single application pool.

 

Web Farm in asp.net.

A hosting environment consisting of multiple web servers is said to be a Web Farm. Usually a load balancer is used to tie together the web servers, which routes incoming requests amongst the servers within the web farm.

This is the case where you have only one web server and multiple clients requesting for resources from the same server. But when are is huge amount of incoming traffic for your web sites, one standalone server is not sufficient to process the request. You may need to use multiple servers to host the application and divide the traffic among them. This is called “Web Farm”. So when you are hosting your single web site on multiple web servers over load balancer is called “Web Farm”. The below diagram shows the overall representation of Web Farms.

In general web farm architecture, a single application is hosted on multiple IIS Server and those are connected with the VIP (Virtual IP) with Load Balancer. Load Balancer IPs are exposed to external world to access. So whenever some request will come to server from clients, it will first hit the Load Balancer, then based on the traffic on each server, LB distributes the request to the corresponding web server. These web servers may share the same DB server or maybe they can use a replicated server in the back end.

So, in a single statement, when we host a web application over multiple web servers to distribute the load among them, it is called Web Farm.