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Control-Based Load-Balancing Techniques: Analysis and Performance Evaluation via a Randomized Optimization Approach

Papadopoulos, Alessandro Vittorio LU ; Klein, Cristian; Maggio, Martina LU ; Dürango, Jonas LU ; Dellkrantz, Manfred LU ; Hernandez-Rodriguez, Francisco; Elmroth, Erik and Årzén, Karl-Erik LU (2016) In Control Engineering Practice 52(July). p.24-34
Abstract
Cloud applications are often subject to unexpected events like flashcrowds and hardware failures. Users that expect a predictable behavior may abandon an unresponsive application when these events occur. Researchers and engineers addressed this problem on two separate fronts: first, they introduced replicas - copies of the application with the same functionality - for redundancy and scalability; second, they added a self-adaptive feature called brownout inside cloud applications to bound response times by modulating user experience. The presence of multiple replicas requires a dedicated component to direct incoming traffic: a load-balancer.

Existing load-balancing strategies based on response times interfere with the response time... (More)
Cloud applications are often subject to unexpected events like flashcrowds and hardware failures. Users that expect a predictable behavior may abandon an unresponsive application when these events occur. Researchers and engineers addressed this problem on two separate fronts: first, they introduced replicas - copies of the application with the same functionality - for redundancy and scalability; second, they added a self-adaptive feature called brownout inside cloud applications to bound response times by modulating user experience. The presence of multiple replicas requires a dedicated component to direct incoming traffic: a load-balancer.

Existing load-balancing strategies based on response times interfere with the response time controller developed for brownout-compliant applications. In fact, the brownout approach bounds response times using a control action. Hence, the response time, that was used to aid load-balancing decision, is not a good indicator of how well a replica is performing.

To fix this issue, this paper reviews some proposal for brownout-aware load-balancing and provides a comprehensive experimental evaluation that compares them. To provide formal guarantees on the load-balancing performance, we use a randomized optimization approach and apply the scenario theory. We perform an extensive set of experiments on a real machine, extending the popular lighttpd web server and load-balancer, and obtaining a production-ready implementation. Experimental results show an improvement of the user experience over Shortest Queue First (SQF) - believed to be near-optimal in the non-adaptive case. The improved user experience is obtained preserving the response time predictability. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
load-balancing, randomized optimization, cloud control
in
Control Engineering Practice
volume
52
issue
July
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:84962868608
  • wos:000377740300003
ISSN
0967-0661
DOI
10.1016/j.conengprac.2016.03.020
language
English
LU publication?
yes
id
ccf16d56-2433-430c-83c2-e6b952e82067
date added to LUP
2016-04-13 17:33:01
date last changed
2017-05-28 04:48:35
@article{ccf16d56-2433-430c-83c2-e6b952e82067,
  abstract     = {Cloud applications are often subject to unexpected events like flashcrowds and hardware failures. Users that expect a predictable behavior may abandon an unresponsive application when these events occur. Researchers and engineers addressed this problem on two separate fronts: first, they introduced replicas - copies of the application with the same functionality - for redundancy and scalability; second, they added a self-adaptive feature called brownout inside cloud applications to bound response times by modulating user experience. The presence of multiple replicas requires a dedicated component to direct incoming traffic: a load-balancer.<br/><br/>Existing load-balancing strategies based on response times interfere with the response time controller developed for brownout-compliant applications. In fact, the brownout approach bounds response times using a control action. Hence, the response time, that was used to aid load-balancing decision, is not a good indicator of how well a replica is performing.<br/><br/>To fix this issue, this paper reviews some proposal for brownout-aware load-balancing and provides a comprehensive experimental evaluation that compares them. To provide formal guarantees on the load-balancing performance, we use a randomized optimization approach and apply the scenario theory. We perform an extensive set of experiments on a real machine, extending the popular lighttpd web server and load-balancer, and obtaining a production-ready implementation. Experimental results show an improvement of the user experience over Shortest Queue First (SQF) - believed to be near-optimal in the non-adaptive case. The improved user experience is obtained preserving the response time predictability.},
  author       = {Papadopoulos, Alessandro Vittorio and Klein, Cristian and Maggio, Martina and Dürango, Jonas and Dellkrantz, Manfred and Hernandez-Rodriguez, Francisco and Elmroth, Erik and Årzén, Karl-Erik},
  issn         = {0967-0661},
  keyword      = {load-balancing,randomized optimization,cloud control},
  language     = {eng},
  number       = {July},
  pages        = {24--34},
  publisher    = {Elsevier},
  series       = {Control Engineering Practice},
  title        = {Control-Based Load-Balancing Techniques: Analysis and Performance Evaluation via a Randomized Optimization Approach},
  url          = {http://dx.doi.org/10.1016/j.conengprac.2016.03.020},
  volume       = {52},
  year         = {2016},
}