② MR Sort Normal To backup tasks 200 processes killed 20000 20000 1000 10000 2000 020040060080010001200 20000 20000 a10000 10000 10000 0200400600800100120 02004006008001000 20000 10001200 20000 10000 10000 020040060080010001200 0 0200 60080010001200 0080010001200 Seconds Backup tasks reduce job completion time a lot System deals well with failures 47MR_Sort 47 Normal No backup tasks 200 processes killed ▪ Backup tasks reduce job completion time a lot! ▪ System deals well with failures