SharePoint Topology - can you have redundant application servers?

I am putting together a recommended architecture with two web servers (for redundnacy) and two search servers (for redundancy)... what about the app开发者_运维问答lication server (for service applications- profile service, managed metadata service etc...?) Can those even have a redundant server? Thanks for any info...

Absolutely. You can have same service running on multiple application server or you can have specific services running on specific application servers. If you want to have understanding of sharepoint topology quickly, I would suggest to take a look at lesson 1 and lesson 2 of the training available at: http://technet.microsoft.com/en-us/sharepoint/ff677987.aspx