Pangolin: Speeding up Concurrent Messaging for Cloud-Based Social Gaming

Chao Zhang, Cheng Huang, Philip A. Chou, Jin Li, Sanjeev Mehrotra, Keith W. Ross, Hao Chen, Felix Livni, and Jay Thaler


The convergence of games and online social platforms is

an exploding phenomena. The continued success of social

games hinges critically on the ability to deliver smooth and

highly-interactive experiences to end-users. However, it is

extremely challenging to satisfy the stringent performance

requirements of online social games.

Motivated by an Xbox Live online social gaming application,

we address the problem of concurrent messaging,

where the maximum latency of game messages has to be

tightly bounded. Learning from a large-scale measurement

experiment, we conclude that the generic transport protocol

TCP, currently being used in the game, cannot ensure

concurrent messaging. We develop a new UDP-based transport

protocol, named Pangolin. The core of Pangolin is an

adaptive decision making engine derived from the Markov

Decision Process theory. The engine optimally controls the

transmission of redundant Forward Error Correction packets

to combat data loss. Trace-driven emulation demonstrates

that Pangolin reduces the 99.9-percentile latency from more

than 4 seconds to about 1 second with negligible overhead.

Pangolin pre-computes all optimal actions and requires

only simple table look-up during online operation. Pangolin

has been incorporated into the latest Xbox SDK - released in

November, 2010 - and is now powering concurrent messaging

for hundreds of thousands of Xbox clients.


Publication typeProceedings
Published inCoNEXT '11 Proceedings of the Seventh COnference on emerging Networking EXperiments and Technologies
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