CollabDraw Real-time Collaborative Drawing Board Shishir Prasad Prashant Saxena Prakhar Panwaria

CollabDraw

 Goals High Scalability High Fault Tolerance Strong Consistency Offline Mode Overview Client

 Clients  Browser  HTML5 local store  Worker Servers  Drawing Board data store  Session Manager  Meta-data store Components

Session Manager Register Workflow

Session Manager Worker Servers Client A Start Session Server IP Preferred Servers Client B Start Session Server IP Workflow

Session Manager Worker Servers Client A getWorker() Server IP Preferred Servers Client B Server Failure

Session Manager Worker Servers Client A Preferred Servers Client B getWorker() Disconnected getWorker () Disconnected Server Failure

Session Manager Worker Servers Client A Preferred Servers Client B Disconnected Mode Server Failure

Session Manager Worker Servers Client A Preferred Servers Client B Disconnected Mode getWorker() Server IP getWorker() Server IP Server Failure

 Hybrid Consistency Strong  Between Preferred Servers : Strong Eventual  Rest : Eventual through anti-entropy protocol  High Availability migration  Worker Failure: Dynamic client migration Disconnected  Network Failure: Disconnected mode  Partition Tolerance replicated  Drawing Boards data replicated CAP

Demo

Evaluation

Evaluation  Average time for a paint brush event to appear on the canvas  Single machine: ~20 ms  2 machines: ~32ms  Average recovery time (in case of server failure)  Single machine: ~18 s (Server up time)  2 machines: ~2 s

Enhancements

Thanks!

Supplement

(1) Main Page

(2) Canvas Page

(3) Dashboard

Evaluation