Research And Implementation Of Seismic Precursor Data Transmission Based On Oracle Advanced Queuing

Earthquake hazard is one of the major natural disasters in the world.It can cause great losses of life and properties in short time. It is anurgent task to reinforce monitoring and predicting earthquakes andreducing earthquake hazard effectively. Seismic precursor data is thebasic information of seismological research and earthquake prediction.After many year's efforts, the government and scientists have set upearthquake monitoring and predicting systems. Especially from the periodof the Ninth Five-Year Project, one third of observational instruments have beenupgraded from analogue to digital. With the construction of the Tenth Five-YearProject of China Earthquake Administration, China Digital Earthquake ObservationNetworks will have an amount of 0.5G seismic precursor data every day. So huge databrings forward higher request for transmission means. Nowadays, Message QueuingMiddleware("MQM") has been used extensively. It is adopted in finance, post andtelecom, traffic and governments. However it is not applied in earthquakeadministration. So it is necessary to study how to transmit seismic precursor data byMQM.With the development of computer and network technology, earthquakeinformation systems are executed on several different hardware systems, thereforesome different system softwares are executed on these hardware desktops. Differentsystem desktops choose different network protocols and structures, so it is a real andtough problem to transmit data between these systems. MQM has the strong ability ofdata transmission and promise to transmit message with credibility. Moreover it canneglect the differences among software, hardware and communication protocols.MQM makes it easy to transmit seismic precursor data.Advanced Queuing("AQ") is the message queuing functionality of theOracle database. Message queuing functionality of AQ enables asynchronouscommunication between applications/users on Oracle database using queues.Using Oracle Net Services, messages are exchanged between a client andthe Oracle database server or between two Oracle databases. Oracle NetServices also propagates messages from one Oracle queue to another. AQoffers multiple ways for applications to place a message in a queue calledenqueue and to get the message from a queue called dequeue. In additionit offers ways to distribute messages to appropriate queues calledpropagation. It offers guaranteed delivery of messages along withexception handling in the case that messages can not be delivered. Itoffers ways to prioritize messages and offers time properties for messagessuch as expiration and delays. With AQ, message queuing operations getall the inherent advantages of a database such as reliability, integrity,high availability, security and scalability. To point a few, all themessage queuing operations are transactional. Once committed, messagesare guaranteed to be delivered. Multiple message queuing and databaseoperations can be performed in the same transaction. Database offers thedisaster protection of these messages. Users of AQ can also use all theadvanced security features of Oracle database. All the AQ operations areautomatically audited. All the messaging information can also be lookedup using a SQL view. These SQL views can be used to extract furtherintelligence about the messaging environment. AQ meets the requirementof the transmission of seismic precursor data completely.There are several questions for transmitting seismic precursor data by AdvancedQueuing. For example, as far as Advanced Queuing is one of MOM, message is theelement of data. How is the seismic precursor data organized in Advanced Queuing?What is the transmission path? As there are many types of precursor data, how toestablish united data structure?First of all, this paper presents the conception and application of Middleware.Then I introduce the conception of MOM and analyze some mainstream MOMproducts. Secondly, I analyze the characters of seismic precursor data, the dataorganization,application system,data transmission and data management. On the basisof these analyses, Advanced Queuing is selected as a method of transmission ofseismic precursor data. This paper also discusses the key technology of AdvancedQueuing and proposes the solutions. Finally a mathematic method was used toanalyze the performance of Advanced Queuing, and comparison was made with MSSQL/Server advanced replication.The results of this paper are as follows:It is a comprehensive research on the transmission of seismic precursordata by Advanced Queuing, involving database technology,computersoftware,computer networks,data management and so on. This transmission methodcan reduce application costs and overcome shortcomings of existing ways. So It issuitable to transmit seismic precursor data safely and credibly.Advanced Queuing is one of MOM, so it can be executed on different operatingsystems and hardware desktops. It can provide several implements of interfaces andprotocols. So it becomes more convenient in accessing data.Message is stored in database table by Advanced Queuing. So users can applystandard SQL to access message information, including message attributes, historicalmessage, and message payload. At the same time, it can track and audit message, somakes management of data easy.Advanced Queuing promises that once committed, messages are guaranteedto be delivered. Moreover it receives data only once, and it will avoidto receive repeatedly. When Advanced Queuing creates queue, it also createsexceptional queue. If data can not reach the destination queue, it will be stored inexceptional queue. so data can not be lost.Advanced Queuing can assign message priority and period of validity ,soimportant data can be transmitted firstly. It also prevents message from being in queuetoo long.Oracle Enterprise Manager ("OEM") is the single tool for managingOracle. Administrative tool of OEM is DBA Studio. DBA studio can be usedto create queue tables, create queues, browse through AQ messages, addAQ subscribers, and manage propagation. DBA studio also shows topologyfor propagation of messages between queues at the database level and thequeue level.In conclusion, Advanced Queuing has great advantages with respect toother means. It is applicable to transmission of seismic precursor data.It can bring forward practical benefit and social benefit. In theconstruction of the Tenth Five-Year Project of China Earthquake Administration,Advanced Queuing can be chosen to transmit seismic precursor data.