Scheduling Summary
•Scheduler (dispatcher) is the module that gets invoked when a context switch needs to happen •Scheduling algorithm determines which process runs, where processes are placed on queues •Many potential goals of scheduling algorithms –Utilization, throughput, wait time, response time, etc. •Various algorithms to meet these goals –FCFS/FIFO, SJF, Priority, RR •Can combine algorithms –Multiple‐level feedback queues –Unix example
Scheduling problems in “big data analytics” •HadoopMapReduce –Users run computation jobs –In nature it is a batch system •FCFS, SJF –But also needs to consider for fairness and priority among multiple users –Further complicated by •sharing the computing cluster with other jobs •some jobs may have deadlines –Lots of interesting problems!