Date Added: Mar 2010
Making cloud services responsive is critical to providing a compelling user experience. Many largescale sites, including LinkedIn, Digg and Facebook, address this need by deploying pools of servers that operate purely on in-memory state. Unfortunately, current technologies for partitioning requests across these in memory server pools, such as network load balancers, lead to a frustrating programming model where requests for the same state may arrive at different servers. Leases are a well-known technique that can provide a better programming model by assigning each piece of state to a single server. However, in-memory server pools host an extremely large number of items, and granting a lease per item requires fine-grained leasing that is not supported in prior datacenter lease managers.