As we mentioned previously, BizTalk Enterprise edition was designed for customers with enterprise-level requirements for high volume, reliability, and availability. While addressing all of these nonfunctional "abilities" of BizTalk, we primarily consider the Enterprise edition.
BizTalk Server lets you separate hosts and run multiple host instances to provide high availability. In large implementations, it is considered best practice to separate the receiving of messages, processing of orchestrations, and sending of messages into three separate groups of hosts. BizTalk automatically distributes the workload across multiple computers through host instances. However, the hosts running receive handlers for the HTTP and SOAP adapters require a load balancing mechanism to provide high availability; hosts running receive handlers for FTP, MSMQ, POP3, SQL, and SAP require a clustering mechanism to provide high availability.
A high availability configuration...