What is the batch processing system?

Batch processing systems (batch processing system), one job can consume CPU for a long time. In time-sharing system, a job can only use the CPU in a time slice (Slice, typically 100ms).

The batch is not strictly the operating system, although monitor can be used monitor, can be used in assembly language development, but also only the prototype operating system.

The so-called batch processing (batch processing) is to group the job according to their nature (or batches), and then group (or batch) to the computer system, automatically completed by the computer and then output the results, thereby reducing the operation of the establishment and end of time waste. According to the number of jobs allowed in memory, batch processing system is divided into single channel batch processing system and multi-channel batch processing system. The early batch system belongs to a single channel batch processing system, which aims to reduce the manual operation during the conversion between jobs, thus reducing the CPU wait time. It is characterized in that only one job is allowed in memory, that is, the currently running job can reside in memory, and the execution order of the jobs is FIFO, in order.

Because in a single channel batch system, a job into memory and exclusive system resources, until the end of the next job can enter the memory, when the job for I/O operation, the CPU can only wait, therefore, CPU utilization is low, especially for I/O operation time longer job. To improve CPU utilization, the multi-channel program design (multiprogramming) technology is introduced on the basis of the single batch processing system, which forms a multi-channel batch processing system, that is, there are several operations in memory, the order of the execution of the operation and the order of entry into the memory are not strictly corresponding. Because these jobs are using a certain job scheduling algorithm to use the CPU, a job waiting for I/O processing, the CPU scheduling another job to run, so the CPU utilization significantly increased.

Now the batch processing system mainly refers to multi-channel batch processing system, it is usually used in the scientific calculation of large and medium-sized computers, because the multi-channel program can alternately use the CPU, improve the CPU and other system resources utilization, but also improve the efficiency of the system. The disadvantage of the multi-channel batch processing system is that it prolongs the working turnaround time, the user cannot intervene directly, lacks the interactivity, and is unfavorable to the development and debugging of the program.

Characteristics of batch processing system:

Multi-channel-holds multiple jobs in memory at the same time, making them run simultaneously, sharing resources such as CPUs and external devices.

Mass-there is no interactivity between the user and his job. Users can not interfere with their own operations, found that job errors can not be corrected in time.

The purpose of the batch processing system is to improve system throughput and resource utilization.

The advantage of multi-channel processing system is that system resources are shared by more than one job, and their working mode is automatic scheduling between jobs. And in the course of operation, users do not interfere with their own operations, thus greatly improving the utilization of system resources and job throughput. The disadvantage is that there is no interactivity, once the user submitted a job will lose the control of its operation, but also batch processing, working turnaround time, the user is not convenient to use.