• If a server was excluded from load balancing because of an error or if it was temporary unavailable then it required administrator to manually add it back. With this release the Web Farm Service will attempt to auto-repair unavailable servers and add them back to load balancing once they become healthy again.
• Non-standard HTTP ports could not be used when communicating with servers in web farm.
• Error caused by race condition between when applicationHost.config is updated and when service reads the configuration.
• Service attempted to add firewall exception and failed if firewall service was not running.
• MSDeploy 1.1 was always installed on servers in the farm, even if MSDeploy 2.0 was available.
• Recycling of the app pool on the controller resulted in HTTP 502 errors.
• Secondary servers kept synchronizing the same changes over and over again.
• When primary server came back after downtime, the provisioning did not start automatically.
• Sync Error “An item with the same key has already been added.”
• User profile was not loaded when service was installed which caused installation failures.

Install the Web Farm Framework 2.1

To install Web Farm Framework 2.1 use the download links at the project’s home page at http://www.iis.net/expand/WebFarmFramework.

If you have Web Farm Framework 2.0 already installed, then it will be updated to v2.1. Note that a reboot maybe required during update and after the reboot the WebFarmService must be restarted on the controller server by using the command below:

net start webfarmservice

More information

• Web Farm Framework 2 Documentation
• Web Farm Framework Forum

• Workflow Builder is used to define and schedule custom tasks that can be run on all servers in the farm. The tasks can be scheduled to run periodically or can be started manually by an administrator. An example of such task could be a msdeploy command to partially sync web site content.
• Windows Credential Store support allows to store the administrator credentials used for server provisioning in a secure Windows Credential Store. This enables an added layer of security when dealing with credentials in Web Farm Framework.
• Third party load balancers support via Web Farm Framework extensibility. It is possible to configure Web Farm Framework to integrate with hardware load balancers instead of relying on IIS Application Request Routing module.
• Improved support for advanced MSDeploy operations. Options of MSDeploy can be used with Web Farm Framework for advanced deployment scenarios.
• Improved support for syncing large amount of files. Several issues related to syncing large amount of files across web farm nodes have been fixed.

In addition to that many bugs reported by beta users were fixed in this release.

Install the Web Farm Framework 2.0 – RTW

To install Web Farm Framework 2.0 use the download links at the project’s home page at http://www.iis.net/expand/WebFarmFramework.

If you have a beta build of Web Farm Framework 2.0 already installed, then it needs to be uninstalled prior to installing RTW build.

More information

• Web Farm Framework 2.0 Documentation
• Web Farm Framework Forum

To demonstrate the capabilities of the tool, we will create a simple web farm that looks as on the following diagram:

• The load balancer will be using the Application Request Routing for IIS 7 and will also act as a Web Farm Controller. Web Farm Controller manages all the machines within the web farm and it has the Web Farm Framework 2.0 installed.
• The Primary Server, in addition to serving the web requests, also acts as an example server for all the other servers in the farm. Web Farm Framework will ensure that every new secondary server added to the web farm has exact same components installed and is configured exactly as the primary server.
• The Secondary Server(s) will serve web requests. It’s configuration and content matches the primary server.

Setting up a web farm

The example web farm will contain 3 servers:

1. DEMOCONTROLLER – this is the load balancer and controller machine. It has ARR 2.0 and Web Farm Framework 2.0 installed.
2. DEMOPRIMARY – this is the primary content server that has a PHP application setup. Here is what is installed on the primary server:
   
3. DEMOSECONDARY – this is the secondary content server that is a clean OS installation without any components or content installed. There is nothing installed on that server:
   

Once the Application Request Routing 2.0 and Web Farm Framework 2.0 have been setup on the controller server, the new web farm can be created by using IIS Manager UI:

In the “Add Server Farm” dialog specify the name for the web farm (e.g. demofarm) and make sure that “Server Farm is available for load balancing” and “Provision server farm” options are selected. You will also need to provide the credentials for the account that exists all all the web farm servers and that has administrative privileges on all those servers.

On next page add the primary server and the secondary server to it. The Web Farm Framework will verify that it can connect to those servers. If connection fails then most probably the firewall on a server is not configured correctly. Follow the instructions at System Requirements for the Web Farm Framework 2.0 to troubleshoot connection problems.

After both servers have been added, the Web Farm Framework starts provisioning the web farm. You can monitor the provision process by using the IIS Manager UI:

Here is what happens during the web farm provisioning:

1. The Web Farm Agent component is installed on both content servers in web farm. The Web Farm Agent is used to establish communication between each content server and the controller.
2. The primary server is added to the Web Farm and Web Deployment Tool is installed on it. Web Deployment Tool is used to synchronize the web content and configuration across all servers in the web farm.
3. The primary server is queried for all the installed components and for the web content.
4. The secondary server is added to web farm and the Web Deployment Tool is installed there too. After that all the same components that were installed on the primary server are also installed on the secondary server.
5. Finally both servers are marked as ready for load balancing, which means that they are now included in the web farm and web request will be routed to them.
   

After both servers have been added to the web farm, the secondary server has exact same components installed and exact same web content as the primary server:

The Web Farm Framework periodically checks all the servers to ensure that they are synchronized with the primary server. If any new component is installed on the primary server or if any content has been changed on the primary server, those changes will be propagated to secondary servers. As soon as another secondary server is added to the web farm, the provisioning process for that server will start automatically. This makes it very easy to add new servers to the web farm. Also, the servers in the web farm do not have to use exact same version of the operating system. For example a web farm can contain a mix of x86 and x64 machines, as well as Windows Server 2008 and 2008 R2.

More information

Automatic provisioning of the servers and applications in a web farm is one of the many capabilities of the Web Farm Framework. Other cool things included in Web Farm Framework are:

• Support for running server operations on the web farm nodes, e.g. starting and stopping services, rebooting and so on;
• API’s for managing web farms;
• PowerShell cmdlets for managing web farms.

More information about the Web Farm Framework 2.0 can be found at Microsoft Web Farm Framework 2.0 Beta for IIS 7.