9 Transactions in RMI Applications

This chapter describes the guidelines and provides additional references for using transactions in RMI applications that run under Oracle WebLogic Server.

Before You Begin

Before you begin, read Chapter 2, "Introducing Transactions," particularly the following topics:

For more information about RMI applications, see Developing Stand-alone Clients for Oracle WebLogic Server.

General Guidelines

The following general guidelines apply when implementing transactions in RMI applications for WebLogic Server:

  • WebLogic Server allows for flat transactions only. Transactions cannot be nested.

  • Use standard programming techniques to optimize transaction processing. For example, properly demarcate transaction boundaries and complete transactions quickly.

  • For RMI applications, callback objects are not recommended for use in transactions because they are not subject to WebLogic Server administration.

    By default, all method invocations on the remote objects are transactional. If a callback object is required, you must compile these classes using the WebLogic RMI compiler using the -nontransactional flag. See "Using the WebLogic RMI Compiler" and "WebLogic RMI Compiler Options" in Developing RMI Applications for Oracle WebLogic Server.

  • In RMI applications, an RMI client can initiate a transaction, but all transaction processing must occur on server objects or remote objects hosted by WebLogic Server. Remote objects hosted on a client JVM cannot participate in the transaction processing.

    As a work-around, you can suspend the transaction before making a call to a remote object on a client JVM, and then resume the transaction after the remote operation returns.

For general guidelines about the WebLogic Server Transaction Service, see Capabilities and Limitations.