local-search

local-search is a location aware Gnutella implementation.

Peers join the overlay with their geographical location (latitude / longitude). Each peer maintains an inventory of items. Other peers can look for items of interest in a particular radius around their own location. These queries can be arbitrary regular expressions that are matched against the inventory of other peers. Location awareness should allow for a more efficient overlay structure and query routing.

Install

1. install Elixir programming language
2. install Hex package manager with mix local.hex --force
3. get the dependencies with mix deps.get
4. build the binary with mix escript.build

Run

Note: the order of command line options matters

To show log messages (including responses to queries) run ./logger.

./localsearch --port=9999 --init --lat=53.548077 --lon=9.962151 starts a bootstrap peer with listening port 9999 at the location given by latitude / longitude

./localsearch --port=9999 --init --lat=53.548077 --lon=9.962151 --lip=188.226.178.57 --lport=9876 starts a bootstrap peer with listening port 9999 at the location given by latitude / longitude that periodically sends status updates to a central log server at 188.226.178.57:9876 (for testing)

./localsearch --port=9998 --bip=127.0.0.1 --bport=9999 --lat=53.548077 --lon=9.962151 starts a normal peer using bootstrap node at 127.0.0.1:9999 at the location given by latitude / longitude

./localsearch --port=9998 --bip=127.0.0.1 --bport=9999 --lat=53.548077 --lon=9.962151 starts a normal peer using bootstrap node at 127.0.0.1:9999 at the location given by latitude / longitude that periodically sends status updates to a central log server at 188.226.178.57:9876 (for testing)

A global log server is aviable at 188.226.178.57:9876 and can be inspected at http://188.226.178.57:3133/

The Implementation of the log-server can be found here.

Test

Run mix test to run a set of unit tests.

Examples

To start some peers copy, paste and run these commands:

./localsearch --port=8000 --init --lat=50.0 --lon=10.0 --lip=188.226.178.57 --lport=9876
./localsearch --port=9001 --bip=127.0.0.1 --bport=8000 --lat=52.22968 --lon=1.050072 --lip=188.226.178.57 --lport=9876 #Hamburg
./localsearch --port=9002 --bip=127.0.0.1 --bport=8000 --lat=39.062144 --lon=125.77113 --lip=188.226.178.57 --lport=9876 #Nordkorea
./localsearch --port=9003 --bip=127.0.0.1 --bport=8000 --lat=-23.668326 --lon=-46.666742 --lip=188.226.178.57 --lport=9876 #Brasilien
./localsearch --port=9004 --bip=127.0.0.1 --bport=8000 --lat=39.77299 --lon=-85.912236 --lip=188.226.178.57 --lport=9876 #USA
./localsearch --port=9005 --bip=127.0.0.1 --bport=8000 --lat=-36.698554 --lon=144.210930 --lip=188.226.178.57 --lport=9876 #Australien
./localsearch --port=9006 --bip=127.0.0.1 --bport=8000 --lat=10.226629 --lon=10.722805 --lip=188.226.178.57 --lport=9876 #Afrika

Roadmap

###Iteration 1 (done)

• Setup Elixir project
• Implement CLI (REPL)
• Implement simple Gnutella 0.4 using location (radius) as a simple filtering criterion.
• Note: Requests are simply flooded and without respect to the location.

####Iteration 1.1 (done)

• mix / build -> Flo -> done
  • use mix escript.build to create executable localsearch file
• TCP / UDP -> Flo -> done
  • run ./localsearch --port 9999 --init to start initial peer
  • run *./localsearch --port 8888 --bootstrap * to connect to this peer
  • Note: everything (including ports) is hardcoded in localsearch.ex, so it works only with these port numbers and on a single machine
• Test-Driven / Unit tests -> Denis done
• REPL / CLI -> Denis done
  • open client
    • if not present: ask for bootstrap IP
    • if not present: ask for location (lat / lon)
  • options:
    • query
      • radius (default: 10 km)
      • item
      • ...
    • add item
    • remove item
    • leave
  • handle responses

Iteration 1.2 (done)

• Implement Gnutella 0.4 -> Flo
  • Joining algorithm done
  • Query algorithm done
    • very simple implementation based on exact strings and without location awareness
• Deal with partial failure (e.g. broken TCP connections) done
  • some errors get caught

Iteration 1.3 (done)

• Feature: Finish REPL done
• Queries:
  • Bug: Filter queries based on location done
  • Feature: Allow for more complex queries done
    • can query by regex and get back multiple results
• Examine / handle more partial failure scenarios done
  • Refactoring: find cleaner way to propagate TCP errors to peer's link list
• Test: Find way to examine overlay structure (e.g. supervisor) done

###Iteration 2 (unfinished)

• Try to optimize joining of peers w.r.t. the location, i.e. try to find peers that are nearby.
  • Maybe it will be necessary to have addititional random links as well, in order to achieve small world characteristics.
  • Still, do not make routing decisions based on locations (may get stuck in local optima)

###Iteration 3 (unfinished)

• Try to optimize routing w.r.t the location, e.g. do not flood requests further than necessary
  • Note: considered hard by Prof. because we may get stuck in local optima