AntSearch: An Ant Search Algorithm in Unstructured
Peer-to-Peer Networks
Apoorva JOSHI
Somanshu DHINGRA
IST-NET2
INSA Lyon
What we will discuss?
- Introduction
4. Advantages / Disadvantages
3. Antsearch Algorithm
2. Need for a new algorithm
5. Q and As
Introduction
Popularity of unstructured P2P
- Scalability
- Decentralization
- Reliabilty
- Heterogenity
Problems
Random Flooding:
- Large network traffic
- Poor search efficiency
- All files may not be returned (constrained TTL)
Improvement
Dynamic Querying :
Based on the popularity of file
Computes a TTL dynamically for each neighbour
BUT....
Freeriders
The root of all problems
~ 96% of the peers are free riders
Make the network congested
Slows down searching
Antsearch
Dynamic Querying
Overcoming Freeriders
Antsearch
Antsearch: Algorithm
Overcoming Freeriders
Pheromone Table:
Probability of being a Freerider
Text
- Alpha defines the weight for each attribute.
- Enables even a new node to be searched.
When is the value of pheromone table updated?
1) When a peer joins into the network
2) When a peer leaves the network
3) When a query is sent to the peers.
=>Low maintenance cost!
Antsearch: Algorithm
-
Probe Phase : Statistics about total number of searched files and corresponding number of searched peers is collected and a probe table is created using this data.
Antsearch: Algorithm
2. Flooding Phase: In order to search 'N' files, TTL is computed for each k. The least value of k is chosen, which satisfies the condition TTL< TTL_max.
Antsearch: Algorithm
TTl(k,nk,D,N)
Antsearch: Algorithm
Title Text
Antsearch vs DQ
- Reduces traffic load by 50% compared to DQ.
- Low maintenance cost.
Advantages
- Load imbalance issues
- For a rare file, it behaves like a TTL constrained random flooding.
Disadvantages
Q and A
AntSearch
By Somanshu Dhingra
AntSearch
An Ant Search Algorithm in Unstructured Peer-to-Peer Networks
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