1. Copyright © 2011, MBL@CS.NCTU Uniform and Non-Uniform Zoning for Load Balancing in Virtual Environments Ahmed, D.T.; Shirmohammadi, S. Embedded and Multimedia Computing (EMC), 2010 5th International Conference on

2. Copyright © 2011, MBL@CS.NCTU Outline Introduction Load Balancing for Non-Uniform Zones Load Balancing for Uniform Zones –Load Balancing –Load Handling Evaluations Conclusions Reference

3. Copyright © 2011, MBL@CS.NCTU Introduction In large-scale applications, resources are usually concentrated on a small number of nodes, which must apply sophisticated load-balancing algorithm to provide continuous and reliable resource access. For easy state administration, the virtual space is divided into multiple adjacent areas, technically called zones. At its simplest, a zone can be represented by a square or a triangle.

4. Copyright © 2011, MBL@CS.NCTU Introduction (Cont.) The workload on a server changes regularly due to the dynamic nature of players and their frequent movements across zones. Hence, a partitioning policy that works well for a static environment or for a slowly-changing environment may not be efficient for a highly dynamic application such as MMOGs.

5. Copyright © 2011, MBL@CS.NCTU Introduction (Cont.) Because of flocking behavior, this could lead to a serious problem called crowding in the virtual worlds - where a large number of players stay in a small area, for example during a battle. A load-balancing algorithm attempts to assign equal numbers of players to partitions while minimizing communication costs between partitions.

6. Copyright © 2011, MBL@CS.NCTU Load Balancing for Non-Uniform Zones In this adaptive zone-shaping approach, the game field is partitioned dynamically based on players’ logical position and interaction pattern. The bisection procedure is used to partition a zone into two sub-zones of nearly equal load while attempting to minimize the communication cost.

7. Copyright © 2011, MBL@CS.NCTU Load Balancing for Non-Uniform Zones (Cont.)

8. Copyright © 2011, MBL@CS.NCTU Load Balancing for Non-Uniform Zones (Cont.) Zone Merging –One of the corresponding zone masters is capable of handling the total load –The lengths of the zone names are equal– say l be the length of the zone names –prefix( Z A ) = prefix( Z B ), and both prefix have length l − 1

9. Copyright © 2011, MBL@CS.NCTU Load Balancing for Non-Uniform Zones (Cont.) Dynamic Cut Movement

10. Copyright © 2011, MBL@CS.NCTU Load Balancing for Uniform Zones Message generation rate, R m (t), a better way to define the load of a zone.

11. Copyright © 2011, MBL@CS.NCTU Load Balancing for Uniform Zones (Cont.) The proposed Multilevel Multiphase Load Balancing(MMLB) method is designed for fixed-size zones. It works in two phases. –The first phase works for the top level microcells and takes care of the inter-server communication while regulating the load among the servers. –The second phase decomposes the top-level microcells into the deep-level microcells and sheds load with the help of enclosing zone masters.

12. Copyright © 2011, MBL@CS.NCTU Load Balancing for Uniform Zones (Cont.)

13. Copyright © 2011, MBL@CS.NCTU Evaluations

14. Copyright © 2011, MBL@CS.NCTU Evaluations (Cont.)

15. Copyright © 2011, MBL@CS.NCTU Conclusions MMLB is designed for fixed-size zones which works in phases that can reduce load in a step-by-step manner and avoid problems associated with the current load balancing schemes. We also have presented another load balancing scheme for non-uniform zones using a bisection procedure that does not adhere to any predefined zone size. According to the simulation results, MMLB performs better than adaptive scheme especially for a series of hotspots.

16. Copyright © 2011, MBL@CS.NCTU Reference Ahmed, D.T.; Shirmohammadi, S.;, "Uniform and Non-Uniform Zoning for Load Balancing in Virtual Environments," Embedded and Multimedia Computing (EMC), 2010 5th International Conference on, vol., no., pp.1-6, 11-13 Aug. 2010