Dprocess on SMP

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

2. Arch Ft process User console Ft event queue Ft daemon Ft_kthread_queue

3. Ft daemon Ft daemon Ft event queue compare error socket error sync error sync error 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

4. 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 • morecentralization, 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

5. 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 Time out? Sync • FT Daemon • User process moniter • Reboot abnormal process Brother gone?

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