| The solutions for achieving high Avalibility database system are range from complete hardware redoundancy to software redoundancy such as standby databases, replicated databases and database cluster of many kinds. The challenge in most HA databases system in compensate not only for unplanned outages but also for planed outages as well.In this paper, firstly we examine the requirements for high availability, the measurees used to express it, causes of downtime and sytem recovery technology. Secondly, we examin the method used to provide HA for systems. Which include hardware solutions, soluteions for HA database and transactional HA solutions. The purpose of the present thesis is to find an economical soluteion for a HA intelligence handling system in navy, which provides fast failover and recovery using Tuxedo software, a transactional middlewareIt is a way to cording businesss transactions that modify database and keeps a write-ahead-log of all the modifications made to the database over a period time. the system allow use of heterogeneous. The system can take the failover from normal mode to degraded mode, in case of node/database failure. The performance of the system is no degraded. and no work is lost. No need for shutdown the machines, the system can recovey from degraded mode to normal mode. it is only needs administerator do a little of work. The HA solution for database system, which makes use of a transactional middleware to solve the synchronization and the recovery, compared with other HA database technology such as real application cluster, the low cost is an advantage. |
PDF Full Text Request