Friday, October 16, 2009 at 7:11AM
We saw in Why are Facebook, Digg, and Twitter so hard to scale? scaling social networks is a lot harder than you might think. This paper, Scaling Online Social Networks without Pains, from a team at Telefonica Research in Spain hopes to meet the challenge of status distribution, user generated content distribution, and managing the social graph through a technique they call One-Hop Replication (OHR). OHR abstracts and delegates the complexity of scaling up from the social network application. The abstract:
Online Social Networks (OSN) face serious scalability challenges due to their rapid growth and popularity. To address this issue we present a novel approach to scale up OSN called One Hop Replication (OHR). Our system combines partitioning and replication in a middleware to transparently scale up a centralized OSN design, and therefore, avoid the OSN application to undergo the costly transition to a fully distributed system to meet its scalability needs. OHR exploits some of the structural characteristics of Social Networks: 1) most of the information is one-hop away, and 2) the topology of the network of connections among people displays a strong community structure. We evaluate our system and its potential benefits and overheads using data from real OSNs: Twitter and Orkut. We show that OHR has the potential to provide out-of-the-box transparent scalability while maintaining the replication overhead costs in check.