Abort And Restart Strategy Of Real-time Transaction Based Based On Function Alternative

In recent years, embedded real-time database system is widely used in industry controls, info-communications, network transmissions and financial applications. Systems of this sort need the running ability without manual intervention, and demand the good ability of self-adaption and flexibility for transaction. The prior research of project team has proved that based on alternative real-time transaction may have multiple execution routes, such that the transaction has the ability of self-adaption and flexibility.Based on the prior research, this paper has researched the transaction abort and restart protocol. On the basis of the real-time transaction based on function alternative, this paper has detailed analyses the properties of alternative and relationship between alternative and transaction and throws light on transaction preanalysis. Against the data conflict in course of alternative processing, this paper has proposed the partial test method based on the static compatibility analysis. The method only detects the compatibility after the current operations between conflict alternatives, which relax the request of transaction compatibility comparatively speaking the prior research. On the basis of partial compatibility test, this paper has analyzed the situation where alternative may abort and proposed the alternative abort protocol, so as to resolve the conflict problem during the alternative running. Simultaneously, this paper has analyzed the situation where transaction may abort and proposed the transaction abort protocol.This paper proposed the restart protocol based on the lowest resource share based on the weight of subtransaction, so to achieve the purpose of reducing the conflict probability and improving the transaction success rate. After aborting one alternative, the system exams whether the aborted alternative meets the alternative restart condition. According to the alternative which satisfies the restart condition, the system handles it according to the algorithm based on the restart protocol based on the lowest resource share.To prove the performance of the abort protocol and the restart protocol, we make simulation experiments on them. This paper elaborates the structure of the simulation experiment system, the experiment model and evaluation criteria, and detailed analyses the results of experiments. The abort protocol and restart protocol which this paper studies is able to reduce unnecessary resource overhead of the system, to improve the transaction success rate, and to strengthen the system ability of self-adaption and flexibility.