Abstract: Methods and apparatus, including computer program products, for communications in a distributed software system. An operation request from a remote computer is received, and provisionally executes an operation identified by the operation request. A first message is generated. The first message contains a transaction identifier identifying the operation request, an unsuccessful indicator flag, and a temporary data store. The temporary data store identifies tentatively written data generated by the operation. The first message is stored in a message store. If the successful completion of the operation is detected, a second message is generated. The second message contains the transaction identifier as well as a successful indicator flag. The second message is stored in the message store, and the message is transmitted to the remote computer. If the failure of the operation is detected, the message stored in the message store is transmitted to the remote computer.

Abstract: A system and method of providing logical locking to shared resources in a distributed Java environment. A plurality of Java virtual machines (JVMs) share a lock server. Each JVM includes a lock manager to interact with the lock server. The lock server provides a centralized source of logical locks for shared resources and maintains a lock table of those locks in a shared memory.

Abstract: A method for upgrading a process running on a first processor includes preparing a second processor, copying process context information to the second processor, starting a second process using the context information on the second processor, and terminating a first process running on the first processor.

Abstract: A method for testing a process running on a first processor includes receiving a request, forwarding the request to a production process and a test process, receiving a response from the production process, and receiving a response from the test process. The responses from the production process and from the test process are used to test the test process.