Research On VM-based Incremental Checkpoint And Execution Replay

Cyclic debugging require us:reproduce the bugs found in test,re-execute the program and locate the root cause of the bug. However, with continuously enriched computer architecture, programming languages , and the rapid development of computer applications ,there are a large number of uncertain factors in modern software which leads to bugs hard to reproduce.To solve this problem ,a so-called execution replay technology have been devised.Its main idea:during the first phase,information about all non-deterministic events are recorded in to a trace file.Then during the replay phase,make sure them exhibit the same effects as we saw in the record phase.Existing execution replay systems need to instrument system library and re-link the program which limit their application.virtual machine Expansion based technology will not need to change the playback applications and operating systems, the system can act and do as much as possible the real circumstances, users can be transparent. So we developed a full system replayer—Bbreplayer,It takes a low time and space overhead. In order to recreate system state quickly during the replay phase and efficiently support system rollback,we present a method to implement an incremental checkpoint based on the Bochs.