网络感知负载均衡Network-Aware Load Balancing.pptVIP

Schedule First, Manage Later Wei Wang Network-Aware Load Balancing Amir Nahir, Ariel Orda, and Danny Raz Presented by Load balancing Load balancing in large distributed server system is a complex optimization problem. Critically important in Cloud systems and data centers. Supermarket Model The supermarket model is a queueing network consisting of servers and independent arrival streams to sets of servers. … Qn Q3 Q2 Q1 At arrival each job is routed to a server from its set where it queues until it is processed and it then departs from the system. The main interest is to study the behavior/efficiency of the system under various simple routing rules, for example join-the-shortest-queue. Problems Regardless of the exact optimization criterion,Common load balancing approaches such as the Supermarket Model, invoke data collection process upon a job’s arrival. This in turn introduces a delay in the execution of the job. Challenge Minimizing the time a job spends till be assigned to a server. Scaling well and being suitable for contemporary data centers. Our scheme Duplicate each job request into several replicas. Send them to randomly chosen servers(FCFS). … Qn Q3 Q2 Q1 When a replica arrives to the head of the queue and begins processing, a signal is sent to the other corresponding servers. Other servers remove corresponding replica. Simulation First-come-first-served M/M/N systems Poisson arrival exponentially distributed service times. Ignore the signaling transmission delay. Assumptions: Simulation setup: A system of 100 servers 100,000 jobs(average of 25) Simulation results The proposed scheme offers high value across all loads compared to the basic random assignment policy. d=2 by a factor of 9.4 d=3 by a factor of 19.9 d=5 by a factor of 47.4 The effect of delay It takes time for the removal message to arrive from one server to the other. It is possible for both replicas of the same job to complete execution at different servers before any removal signal