www.xjtu.edu.cn Dprocess on SMP Siyuan Ma

Arch Ft process User console Ft event queue Ft daemon Ft_kthread_queue

Ft daemon Ft daemon Ft event queue sync error compare error socket period event sync error sync error handler compare error handler period event handler Kill the error process Check ft queue close the ft mode Tell the console Report to console Tell the console fork a new twin log

Ft daemon cons central fault handler make it easy to change the ft policy do not affect the running of ft processes even if it is down pros Single Point of Failure more centralization, less fault tolerance able to improve sort the event queue before handler it, more analysis More option in console Periodic reboot to overcome the Single Point of Failure

User process breakdown Code Seg 1 Sync 1 Code Seg 2 Sync 2 Code Seg 3 Sync 3 Process X Code Seg 1 Sync 1 Code Seg 2 Sync 2 Code Seg 3 Sync 3 Process X’ Sync sleep on a queue to wait brother add a timer timer Sync? Time out? Sync FT Daemon User process moniter Reboot abnormal process remove the timer Wake up the brother Brother gone?

Recovery process x process x’ process x’’ Ft daemon handler sync killed by daemon double fork process x sync timeout sync sync exit wake up process x’ fork by process 2 exit process x’’ Ft daemon handler