Achieving resilient and efficient load balancing in DHT-based P2P systems

In DHT-based P2P systems, the technique of "virtual server" is widely used to achieve load balance. To efficiently handle the workload skewness, "virtual servers" are allowed to migrate between nodes. Among existing migration-based load balancing strategies, there are two main categories: (1) Rendezvous Directory Strategy (RDS) and (2) Independent Searching Strategy (ISS). However, none of them can achieve resilience and efficiency at the same time. In this paper, we propose a Gossip Dissemination Strategy (GDS) for load balancing in DHT systems, which attempts to achieve the benefits of both RDS and ISS. GDS doesn't rely on a few static rendezvous directories to perform load balancing. Instead, load information is disseminated within the formed groups via a gossip protocol, and each peer has enough information to act as the rendezvous directory and perform load balancing within its group. Besides intra-group balancing, inter-group balancing and emergent balancing are also supported by GDS. To further improve system resilience, the position of the rendezvous directory is randomized in each round. For a better understanding, we also perform analytical studies on GDS in terms of its scalability and efficiency under churn. Finally, the effectiveness of GDS is evaluated by extensive simulation under different workload and chum levels.