A First Look at a Hybrid Content Delivery

A First Look at a Hybrid Content Delivery System Ming-Chen Zhao, Paarijaat Aditya, Yin Lin Andreas Haeberlen, Peter Druschel, Bruce Maggs, and William Wishon

Akamai Network Deployment 160000+2500+ 1000+ 79+ Servers POPs Networks Countries Powering a Better Internet © 2011 Akamai

Akamai Peak Instant and Daily Statistics • Bit rate (01/09/11): 4. 8 Tbps • Request rate (02/21/11): 16. 7 million hits/sec • Bytes delivered (12/27/10): 42. 3 Pbytes • HTTP requests received (02/21/11): 961. 5 billion • Unique client IPs (02/16/11): 471. 5 million Powering a Better Internet © 2011 Akamai

Download Manager Product/Service • Hybrid between a fixed-infrastructure CDN and a pure peer-to-peer delivery system • Based on technology developed by Red Swoosh (acquired by Akamai in 2007) • Goal is to deliver large files at lower cost Powering a Better Internet © 2011 Akamai

Net. Session Interface • client-side software • runs as a service on Windows or Mac. OS • provides an API to installation software or browser • stays connected to an Akamai Control Node • each installation is supposed to have a unique GUID Powering a Better Internet © 2011 Akamai

Growth in Number of Installations Full product roll-out expected summer 2011. Powering a Better Internet © 2011 Akamai

Architecture Peers Akamai Control Nodes Akamai Edge Servers • Bit. Torrent-like protocol with control nodes serving as “trackers” and assigning peers • CDN acts as a backstop Powering a Better Internet © 2011 Akamai

Logging • Content providers want all downloads to be logged • Peers must report P 2 P downloads to control nodes as they occur • Akamai Edge Servers also log downloads from peers Powering a Better Internet © 2011 Akamai

Statistics from December 2010 Logs Powering a Better Internet © 2011 Akamai

Locations of Clients per Edge. Scape Granularity of predictions varies by continent. Powering a Better Internet © 2011 Akamai

December Client Logins What happened December 8? Powering a Better Internet © 2011 Akamai

IP Addresses per GUID in December Category 3 (flagged) look like multiple installations with the same GUID. Powering a Better Internet © 2011 Akamai

Clients Leave P 2 P Setting Unchanged Content provider decides on initial setting. Powering a Better Internet © 2011 Akamai

File Size Distribution For customers other than J and F, median file size was 872 MB. Powering a Better Internet © 2011 Akamai

P 2 P Efficiency for Largest Enabled Customers Matches or exceeds earlier predictions. Powering a Better Internet © 2011 Akamai

Efficiency versus Number of Peers Powering a Better Internet © 2011 Akamai

Success Rates, All Downloads Over 86% success rate in December 2010. Powering a Better Internet © 2011 Akamai

Terminations and Failures Occur Early Powering a Better Internet © 2011 Akamai

Performance Majority P 2 P downloads average several Mbps. Powering a Better Internet © 2011 Akamai

Content Popularity Typical? Powering a Better Internet © 2011 Akamai

Net. Session Versions Observed in Field Net. Session should excel at downloading itself. Powering a Better Internet © 2011 Akamai

Ongoing Work • Designing mechanisms to protect the logging system against attacks • (Successfully attacked it ourselves. ) Powering a Better Internet © 2011 Akamai