The concept of transaction originates from database research. It is a key technology to ensure the reliabilityand consistency of information. The flat transaction model is not suitable to current complex and distributed applica-tions since it lacks the semantic support for complex applications. In this paper, we survey two approaches to solvethe problems of the flat transaction model: extended transaction models and transactional workflows. We then pre-sent the transaction specifications and major commercial products of transaction processing technologies. Finally, weprospect the trend of these technologies.
In distributed systems,high efficiency can be achieved using asynchronous API between client and server.This paper provides an architectural pattern that implements asynchronous API generally. Asynchronous methods donot execute operations directly,however,they delegate the sending and receiving process to individual threads via aqueue ,the client deals with results by means of callback ,wait or check. Synchronous API is implemented on the baseof asynchronous API. Presently the asynchronous API pattern has been employed in the implementation of messagequeue middleware ISMQ.
The environment of distributed transaction involves a number of resource managers,and we should do operations on resources such as connection and enlistment.during a transaction. Connecting to a resource will cost a lot of time,so connection pool mechanism is put into use on account of improving performance. And the resource connections in the connection pool need to be scheduled properly. In this paper,we specify how to implement resource enlistment and delistment in a distributed transaction,and present an algorithm of resource connection reusing and scheduling. Now the resource connection reusing and scheduling algorithm has been successfully employed in the implementation of the distributed transaction manager ISTX 1.0 system.
