Home » Getting started » Installing » Load balancing considerations
When dealing with load balancing you have some times to take special care to make it work. We have tried to put down some pit falls here.
Using the built in Network Load Balancing service (NLB)
When using the NLB fetures of Windows, make sure that all machines with the same web site, uses the same site id. Eg. On wwwmachine1 the site ID for the web site www.company.com MUST have the same site ID as the www.company.com site on wwwmachine2.
The Site ID setting is only available on a Windows Server box. Change the setting to an ID not used by any other site on any machine.
Syncronized time for cache updates
Due to the way the built in cache works you must make sure that all web servers in your cluster, have the same correct time. Use a sync tool or ntp time to make sure its correct. If time differs, you may experience delays in cache changes and public site updates. However at every hour (or what ever time is configured for cach), the cache is reloaded so problems of this nature is transistent. The cache is also reloaded at computer restart.
Machine key
The machine key must be the same on every web server. It can be overriden for the site in web.config. Use the machine key generator to create a working key for your servers.
asp.net machine key generator
http://www.developerfusion.com/tools/generatemachinekey/
ASP.NET State Service
The ASP.NET state service must be installed on central server. In many deployment scenarios it´s good enough to install it on the database server. In web.config on each web server enter/change the configuration to point to that new central server.
Scensum services
Normally theye are configured on two of the web servers but only started on one instance (automatic). This way one server acts as the primary "backoffice" server and the second one is a working standby copy, ready to take over such services if the first machine should fail. Of course you have to manually start these services at that point if you do not use any other monitoring software with resonse capabilities.