Elastic Routing Table (ERT) Mechanism For Query Load Balancing In Consistent Hashing-Based DHT Networks

International Journal of Computer Science (IJCS) Published by SK Research Group of Companies (SKRGC).

Abstract

Consistent hashing-based DHT networks have an inherent load balancing problem. The problem becomes more severe in heterogeneous networks with non-uniform and time-varying popular files. Existing DHT load balancing algorithms are mainly focused on the issues caused by node heterogeneity. To deal with skewed lookups, this paper presents an elastic routing table (ERT) mechanism for query load balancing, based on the observation that high-degree nodes tend to receive more traffic load. The in-degree and out-degree of the routing table can also be adjusted dynamically in response to the change of file popularity and network churn. Theoretical analysis proves that the routing table degree is bounded. The ERT mechanism facilitates locality-aware randomized query forwarding to further improve lookup efficiency. By relating query forwarding to a supermarket customer service model, we prove that a two-way randomized query forwarding policy should lead to an exponential improvement in query processing time over random walking. Simulation results demonstrate the effectiveness of the ERT mechanism and its related query forwarding policy for congestion and query load balancing. In comparison with existing “virtual-server”- based load balancing algorithms and other routing table control approaches, the ERT-based congestion control protocol yields significant improvement in query lookup efficiency. DHT routing algorithms may lead to the convergence of query load targeted for an object on a small number of nodes around the destination, leading to bottlenecks.

References

[1] Steve Harris and Robmac Donald, “Web Development with VB.NET” -A press.
[2] Matthew Macdonald, “Microsoft Visual Basic.NET Programmer’s Cookbook” -Tata Mcgraw Hill Edition
[3] Chris Goode, John Kauffman, “Beginning ASP.NET 1.0 with Visual Basic.NET” -Wrox Programmer to Programme.
[4] Douglas O.Reilly, “Designing Microsoft ASP.NET Applications -Tata Mcgraw Hill Edition.

Keywords

Elastic Routing Table, Heterogeneous Networks, Virtual Server, Load Balancing Algorithm.