Abstract
We analyze the possibility of using an 'Internet-like' power-law graph
as a basis for peer-to-peer distributed hash table applications. Our work is
based on previous studies of power-law random graph models that showed
emergence of a spontaneous hierarchy of nodes based on their degrees, called
the 'soft hierarchy'. The soft hierarchy indicates very short paths, leading
to the top of the hierarchy, where the top consists of a clique of highest
degree nodes. Such paths have lengths that scale as log log N, with number of
nodes N. Further, such paths can be found by a heuristic rule: 'the next hop
to highest degree neighbor'. We suggest that these circumstances could be used
as a basis of an efficient distributed hash table. The idea is that the
hash-entries, needed to locate content, are stored at the periphery of the
hierarchy, consisting of large enough set of nodes to guarantee small tables.
It is required that any node, say, i in the hierarchy is aware which nodes are
below it in the hierarchy, provided it is not in the periphery. The node i
places its 'down-hill' neighbors in the hash-ring with equal intervals between
them. When node i gets a request to store or search a given hash-entry, it
uses some locally defined function that places the hash value on this ring and
forwards it to the down-hill neighbor closest to this value. Our main result
is a probabilistic estimate of the number of hash-values stored in a periphery
node. It appears to be sub log log N and super log log log N, with N ->
infinity, and with probability tending to 1. Another contribution is a sketch
of a novel algorithm that would create such topologies in a self-organizing
manner.
Original language | English |
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Title of host publication | 4th International ICST Conference on Performance Evaluation Methodologies and Tools |
Number of pages | 10 |
DOIs | |
Publication status | Published - 2009 |
MoE publication type | A4 Article in a conference publication |
Event | 4th International ICST Conference on Performance Evaluation Methodologies and Tools, VALUETOOLS 2009 - Pisa, Italy Duration: 20 Oct 2009 → 22 Oct 2009 |
Conference
Conference | 4th International ICST Conference on Performance Evaluation Methodologies and Tools, VALUETOOLS 2009 |
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Abbreviated title | VALUETOOLS 2009 |
Country/Territory | Italy |
City | Pisa |
Period | 20/10/09 → 22/10/09 |
Keywords
- peer to peer network
- distributed hash tables
- power-law graphs