Deferred service is used to send DB data of the source system to the target system in real time. Deferred service follows the preassigned process interval, and the interval is adjusted according to the data number to be processed. To apply deferred service, the data structure of the target DB should include the serial number field. Deferred service executes its operation through the serial number, so the processing method depends on the way to manage the serial number. Serial number field should be included on data verification result, and the pertinent field must be assigned to key field(ISM:DeferredDB#Source DB Data Structure Definition).
Deferred runtime comprises of ISM agent, deferred manager, and the interface process executing the interface between each source and target systems. Deferred service is able to be configured to either master-backup mode or active-active mode.
Deferred service is started and controlled by ISM agent. ISM Agent request the job execution according to the job cycle, and the deferred manager execute the requested job by the source and target interface processes and manage the transaction. ISM agent is the ISM common process existing in the same server or domain.
When a failure occurs on the way of the service at the transmission process, the deferred manager of master server executes the service by sending request to transmission process of backup server. The deferred manager of master server determines the location of the target interface process according to the location of the source interface process. The interface between the source and target process is executed regardless of where the source process located only when the shared disk is set between master and backup server, and if they are accessible to both servers. For example, the source interface process is able to be configured to executed in master server, and the target interface process is to executed on backup server.
ISM agent controls the deferred job, gives directions to data inquiry/application. If each result of the process succeed, proceed to the next step. If it fails, rollback the process. It also manage the working directory(serial number) and conduct the process after the current position when the next request is made. It also manage the location(the serial number) which has processed so far, and process since then when the next job request is received. The processed information to the current location is included in the transaction range of the deferred service.
Interface Process executes the role of getting the data or sending the data.between the source and the target systems. Transmit-Receive process is separated by the role in the service, each interface process execute both of the roles of the source and the target.
Common process is registrable similar to the common process of batch service. If the pertinent service assign the alternative system according to the system registered to ISM, the deferred manager finds the alternative system process not the current pertinent system and send the execution request. Agent service is defined to each deferred source/deferred target type. In the case of file system, the target interface is able to be processed by agent system. In the case of DB system, the source interface is able to be processed by agent system.
The interface types supported in deferred service as described below.
When the user wants an additional interface type, custom source process or target process should be implemented. The way to send data to the target system by service call can be implemented by custom interface.