Fault Recovery Strategy Research On The Real-time Embedded Memory Database ARTs-EDB

Embedded database system is a new kind of database techniques, and it is based on current mature database technology. It also makes achievement initiatively to embedded devices on data storage, organization and management. Data and transaction have explicit temporal restrictions in real-time database. The accuracy of the system not only depends on the results of logic but also depends on the outcome of the logic of the time. The high-performance requirements of RTDB cause memory database as its underlying support. Memory database systems could meet a variety of applications of real-time data requirements well.ARTs-EDB is an embedded active real-time database which had been researched and designed by Huazhong University of Science and Technology who owned intellectual property rights. This system integrates the traditional database, the real-time database and the initiative mechanism. ARTs-EDB takes memory database as its underlying support. Secondary database could be used for backup of the recovery system in memory database. In order to meet consistency state after the database system having a fault, the recovery sub-system needs to write logs, make checkpoints, backup or reload system.For the log strategy, every transaction has its own active log district, and records the REDO log. It also uses the appropriate log protocol to reduce the occupied space and record the workload of logs. For the checkpoint strategy, it uses fuzzy checkpoint to meet active consistency; For the reloading strategy, it is based on the priority of data and transaction, different characteristics of them which have been distributed for different priorities. The data of emergency priority and high-priority would be reloaded, so it could make the system work into a state of affairs in the shortest possible period of time to meet the operation of real-time transaction; For the backup strategy, it uses a dynamic way of incremental backup, and records logs in processing of backup. The copy and the log file of database system would make up into a complete backup together.This paper introduces the development and technical characteristics on real-time embedded memory database. In particular to make a comprehensive analysis for the recovery technology, it is combined with our own active real-time database management system ARTs-EDB. Based on the analysis of the overall structure of the ARTs-EDB, it has proposed the recovery mechanism and the achieved strategy on ARTs-EDB.