Improvement Of Queue Scheduling Algorithm Based On Iscsi Data Stream

i SCSI protocol is built bearer transmission over TCP / IP network, it will be affected by many factors during actual transmission, the overall transmission performance of i SCSI is also limited by TCP / IP protocol stack and Ethernet load maximum bandwidth. In addition, i SCSI protocol layer protocol itself will have some extra overhead load. Therefore, in practical applications, i SCSI data transfer performance bottlenecks still exist. Research on i SCSI virtual switch traffic scheduling algorithm, it is possible to optimize performance for a particular i SCSI PDU data stream, thereby it can improving overall performance of i SCSI virtual storage system, and from another dimension to improve i SCSI transfer rate.First, the dissertation introduced for the theory of i SCSI model and queue scheduling algorithms. Then put forward by the standard WFQ algorithm for i SCSI data stream based on improved on the basis of this combined with the sr TCM algorithm, proposed STM_WFQI queue scheduling algorithm. The STM_WFQI algorithm includes WFQ algorithm and sr TCM algorithm. And illustrated the principle of GPS algorithm and GPS algorithm are analyzed, then the WFQ algorithm is introduced. WFQ algorithm introduces the concept of virtual time, through packet virtual start time and end time of the virtual computing, which are forwarded according to the smallest virtual finish time. Based on i SCSI data stream transmission characteristics can be on the data flow of real-time optimization, depending on whether it is a real-time data flow to the packet data to adjust weights and the virtual finish time is adjusted, thus the real-time data packets were priority forwarding. Fusion sr TCM algorithm based on the classifier in the default rule, after the i SCSI data stream packet arrival classifier, the classifier according to the default rules to determine the packet. Data packets that meet the filtering conditions are sent to the token bucket for token control, and then sent to each queue. The data message which is not satisfied with the rules is sent directly to the queue for scheduling and forwarding.Finally according to the theory of algorithm, in the NS-2 simulation platform, through tests of i SCSI virtual switch improved needle for i SCSI data flow scheduling algorithm is verified. Finally, we validate the rationality and validity of theoretical research.