Citrix Independent Management Architecture (IMA)

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　　http://www.brianmadden.com/blogs/citrix_metaframe_xp_advanced_technical_design_guide_including_feature_release_2/pages/independent-management-architecture-ima.aspx
　　MetaFrame XP is the first Citrix product that uses Citrix's Independent Management Architecture (IMA). The Citrix product literature describes IMA as if it's a magical solution that makes working with MetaFrame XP effortless. In the real world, MetaFrame XP's IMA consists of two components that we actually care about.
　　Independent Management Architecture is:

• A data store, which is a database for storing MetaFrame XP server configuration information, such as published applications, total licenses, load balancing configuration, MetaFrame XP security rights, and printer configuration.
  
• A protocol for transferring the ever-changing background information between MetaFrame XP servers, including server load, current users and connections, and licenses in use.
  

　　In MetaFrame XP, IMA does not replace the ICA protocol. The ICA protocol is still used for client-to-server user sessions. The IMA protocol is used for server-to-server communication in performing functions such as licensing and server load updates, all of which occur "behind the scenes."

Figure 3.1: MetaFrame XP network communication

　　If you're familiar with previous versions of MetaFrame, MetaFrame XP's IMA does replace the ICA Browser Service. Not to be confused with the ICA protocol, the ICA Browser Service (in previous versions of MetaFrame) was used to replicate MetaFrame server configuration information between servers. This was needed because that information was stored in the local registries of each server. (They didn't use a central database, like IMA does). That ICA Browser Service was notoriously bug-ridden, extremely chatty, and didn't scale very well. Today, of course, all of that information is stored in the IMA data store. (For more information about integrating MetaFrame XP with the previous version of MetaFrame, see Chapter 13.)
　　Today, every MetaFrame XP server runs the "IMA Service." This service is the actual component that communicates with the IMA data store and other MetaFrame XP servers. Additionally, this IMA service communicates with the Citrix Management Console to allow administrators to manage and configure servers.