SELF-ADAPTIVE CONTROL SYSTEM FOR DYNAMIC CAPACITY MANAGEMENT OF LATENCY-SENSITIVE APPLICATION SERVERS

摘要

A self-adaptive control system based on proportional-integral (PI) control theory for dynamic capacity management of latency-sensitive application servers (e.g., application servers associated with a social networking application) are disclosed. A centralized controller of the system can adapt to changes in request rates, changes in application and/or system behaviors, underlying hardware upgrades, etc., by scaling the capacity of a cluster up or down so that just the right amount of capacity is maintained at any time. The centralized controller uses information relating to a current state of the cluster and historical information relating to past state of the cluster to predict a future state of the cluster and use that prediction to determine whether to scale up or scale down the current capacity to reduce latency and maximize energy savings. A load balancing system can then distribute traffic among the servers in the cluster using any load balancing methods.

主权项

1. A system, comprising:
a processor and memory; and a controller deployed in a cluster, the controller being a part of a self-adaptive feedback control system, the controller configured to periodically:
determine a current value of an operating parameter based on values of the operating parameter from servers in an active mode in the cluster, wherein an amount of servers in the active mode represents a current capacity;determine a total request rate for the cluster;determine, based at least in part on the current value of the operating parameter and control parameters, a change in a per server request rate to cause a next value of the operating parameter to approach a target value of the operating parameter; anddetermine, based at least in part on the change in per server request rate and the total request rate, a required capacity.