Team Members Abhinav Mishra Amber Palekar Rahul Iyer
Team Members Abhinav Mishra Amber Palekar Rahul Iyer Vishakha Gupta
Imagine Cup Presentation Carnegie Mellon University Team O(1)
Agenda • Motivation • Innovation • System Design Overview – – – • • Databases Compute Servers Web Servers Traffic model and Data Collection Servers Maps Quantitative Measurements Architectural Highlights Future Directions Questions/Comments
Looks Familiar?
Motivation & Aim • Get you to your destination faster • Optimal Routing on Roads using Dynamic Traffic Balancing • Gives you the “best” route to your destination – Optimal Time – Optimal Distance
Innovation • Different from Yahoo Maps, Map. Quest, Google Maps – Bidding good bye to static maps • Leveraging cutting edge technologies – Minneapolis has already deployed traffic sensors at intersections • Scalability and Fault-tolerance built into system (and not “patched” onto it)
A Problem Let’s just meet somewhere! I have an idea! Let’s meet at the Subway on 41 st. I’m leavin’ for the Starbucks on 42 nd, c’ya guys there!
Our Solution Where should we meet? Thai Café on 43 rd is your best option Thai Café on 43 rd is your Where best should option we meet? Thai Café on 43 rd is your best option Where should we meet?
System Design Overview Maps DB Handler Traffic Model
Architectural Highlights • Load Balancing – Web Servers – Compute Servers • Scalability – Compute Servers – Database* • Fault tolerance – Compute Servers: designed to be stateless – Web Server – Database*
Quantitative measurements • Original Design targeted at a 1000 intersection map • Current system considers all of Allegheny county – ~45, 000 Intersections & 60, 000 Roads • Loading the map for all of Allegheny county takes about 6 seconds • We update the map every minute – Update takes roughly 3 seconds
Future Directions • Server-side map generation engine • More elaborate model for simulation of real-life traffic • Enabling SMS results for user queries • Better text prediction algorithms for the mobile GUI • Sturdier database infrastructure – 2 Phase Commit is too slow?
Postmortem • . NET – a boon for software development – Fast, Handy, Bundled with an excellent IDE – ADO. NET: simple to use • Microsoft SQL Server: fast! – ASP. NET: enabled deployment on mobile devices –. NET Remoting: shorter learning curve – Performance counters • Oh how we wish! – that ADO. NET allowed >2 data readers – that we could try this on Windows Server 2003
Questions
Thank You
User GUI • User chooses source and destination intersections from dropdown lists & chooses one of the time-optimal or distanceoptimal route options • Remotely invoke route computation algorithm at the compute server • Commercial Value – Advertisement Server
Administrator Interface • Handy tool for the Cruise Control Administrator • Saves configuration time, designed to handle large number of nodes/links • Add/Modify/Delete on: – Nodes – Links – System Parameters • Uses backend Admin. Interface class which talks to the DB handler
Compute Servers • Uses optimized version of Dijkstra’s algorithm with a priority queue implementation to improve scalability. – Euclidean distance as a heuristic to converge faster on routes • Refreshes the graph – Every ‘refresh. Interval’ – Whenever node and link details change in system • Registers itself with the. NET registry to make itself available for remote invocation (uses Singleton) • Answers requests from web server, on-demand • Fault tolerance – handle lost DB connectivity for a while • Load balancing – server-initiated load balancing
DB & DB Handler • The Database Handler provides an interface for clients to access the database • The DB Handler acts like a “stub” providing marshalling and un-marshalling • Database Daemons act as “middlemen” between the client DB Handlers and the databases • Uses TCP connections instead of Atomic Broadcast
Traffic Model & Collection • Traffic model periodically generates load over each link in the map depending on the type of road – Downtown roads are “Heavy” at rush hour – Small streets aren’t • Model sends periodic updates to collection server as a formatted string • Multi-threaded server collects data generated by traffic model, parses it & updates the DB • New models can be seamlessly plugged in • Fault tolerant, replicated servers running • Highly Scalable
Web Server • Uses Microsoft IIS • On request, remotely invokes compute nodes to calculate optimal route • Fault tolerant • Load balancing • Highly available • Ad Server runs on Web Server – Decides ad to post
Maps • Tiger Maps – Street Level Maps – Census Information for: • Counties • Street Names • Zipcodes • The Groove. Net project – Uses Tiger Maps – Interprets them as a graph • We leverage existing map interpretation code of Groove. Net – Populate database with data from Groove. Net
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