A self-organizing job scheduling algorithm for a distributed VDR
Kendy Kutzner, Curt Cramer, Thomas T. Fuhrmann · 2005
In [CKF04], we have reported on our concept of a peer-to-peer extension to the popular video disk recorder (VDR) [Sch04], the Distributed Video Disk Recording (DVDR) system. The DVDR is a collaboration system of existing video disk recorders via a peer to peer network. There, the VDRs communicate about the tasks to be done and distribute the recordings afterwards. In this paper, we report on lessons learnt during its implementation and explain the considerations leading to the design of a new job scheduling algorithm. DVDR is an application which is based on a distributed hash table (DHT) employing prox-imity route selection (PRS)/proximity neighbor selection (PNS). For our implementation, we chose to use Chord [SMK+01, GGG+03]. Using a DHT with PRS/PNS yields two im-portant features: (1) Each hashed key is routed to exactly one destination node within the system. (2) PRS/PNS forces messages originating in one region of the network destined to the same key to be routed through exactly one node in that region (route convergence). The first property enables per-key aggregation trees with a tree being rooted at the node which is responsible for the respective key. This node serves as a rendezvous point. The second property leads to locality (i.e., low latency) in this aggregation tree.