Design And Implementation Of User-level Process Checkpointing System Based On Linux

Process checkpoint mechanism is that we can set up the checkpoints in the appropriate moment of the normal operation of the process to put the saved process state into stable storage by checkpoint file. If the process failed in the subsequent operation of the process, we can read out the saved process state from the memory to recover the process and continue to run, thus avoiding being executed from the beginning, reducing the loss of calculation.In the background of widely used of computer technology, how to ensure that the system has certain reliability in order to avoid the occurrence of disastrous consequences, is a very important area of current research. Now because of the continuous growth in size of the system, increasingly complex of the application, the defects in the existing system and the probability of errors is greatly increased. In order to ensure high reliability of system, the technology of checkpoint has been widely used and become a hot field of computer research. In addition, with the growing popularity of Linux systems, applications based on the operating system is more and more widely used,so the process checkpoint mechanism applied in the system, in order to improve the system software fault tolerance has been paid more and more attention.First of all, the article reviews the technology of checkpoint and current research situation at home and abroad. Through the analysis of existing user-level process checkpoint systems, it sums up the difficulties and problems need to be resolved of the process checkpoint system. Then introduce the key technology of realizing the checkpoint system and its principles.This article focuses on the design and implementation of user-level process checkpoint system. The system is divided into four modules:Fault detection module、 State saving modules、Write file module、Process recovery module. Fault detection module can achieve real-time protection of the target process and keep the process run normally; State saving modules can record and save the state of normally running target process such as the process memory image and CPU registers, signal, open the file; Write the file module is responsible to write the saved state of process into the checkpoint file; Process recovery module can return the saved state to its previous state and ensure the process continues to run.Second, write the object program to verify the operation of each module of the system, and ensure the normal operation of each module.Finally, summarize the main work of this paper, and propose some measures to improve and perfect the paper.