A Load Balanced Two-Tier DHT with Improved Lookup Performance of Non-popular Data Items

  • Mayank Pandey
  • Banshi Dhar Chaudhary
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6646)


We have earlier proposed a two-tier hierarchical DHT architecture where nodes with higher uptime and more resources dynamically form the upper tier DHT ring. Each node of this ring acts as a super node for a DHT ring of lower tier nodes. The performance of lookups for non popular data items in this type of self organizing two-tier DHT is not as good as that of flat DHT due to the uneven distribution of ring sizes at lower tier. Also, this uneven distribution leads to unbalanced load at super nodes. In this paper, we propose a dynamic node migration algorithm for forming two-tier DHT which ensures even distribution of ring sizes at lower tier. Our proposed migration algorithm includes mechanisms for merging smaller rings and splitting bigger rings. Further, this even distribution of lower tier ring sizes leads to improved load balancing among super nodes. Simulation results indicate that this modified two-tier DHT architecture performs better than flat DHTs in terms of mean hop count to lookup non popular data items.


Hierarchical DHT Load balancing 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Mayank Pandey
    • 1
  • Banshi Dhar Chaudhary
    • 1
  1. 1.Department of Computer Science and EngineeringMotilal Nehru National Institute of TechnologyAllahabadIndia

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