Click here to view and discuss this page in DocCommentXchange. In the future, you will be sent there automatically.

SQL Anywhere 17 » SQL Anywhere Server - Programming

Three-tier computing and distributed transactions

You can use the database server as a resource manager, participating in distributed transactions coordinated by a transaction server.

A three-tier environment, where an application server sits between client applications and a set of resource managers, is a common distributed-transaction environment. Application servers provide transaction logic to their client applications, guaranteeing that sets of operations are executed atomically. SAP Enterprise Application Server (SAP EAServer) and some other application servers are transaction servers.

SAP EAServer and Microsoft Transaction Server both use the Microsoft Distributed Transaction Coordinator (DTC) to coordinate transactions. The database server provides support for distributed transactions controlled by the DTC service, so you can use the database server with either of these application servers, or any other product based on the DTC model. DTC uses OLE transactions, which in turn use the two-phase commit protocol to coordinate transactions involving multiple resource managers. You must have DTC installed to use distributed transactions.

When integrating the database server into a three-tier environment, most of the work needs to be done from the application server. The concepts and architecture of three-tier computing are introduced, and an overview of relevant database server features is presented. It does not describe how to configure your application server to work with the database server. For more information, see your application server documentation.

You can also use DTC directly in your applications to coordinate transactions across multiple resource managers.