document: WAP5 : black-box performance debugging for wide-area systems Wide-area distributed applications are challenging to debug , optimize , and maintain . We present Wide-Area Project 5 ( WAP5 ) , which aims to make these tasks easier by exposing the causal structure of communication within an application and by exposing delays that imply bottlenecks . These bottlenecks might not otherwise be obvious , with or without the application 's source code . Previous research projects have presented algorithms to reconstruct application structure and the corresponding timing information from black-box message traces of local-area systems . In this paper we present ( 1 ) a new algorithm for reconstructing application structure in both local - and wide-area distributed systems , ( 2 ) an infrastructure for gathering application traces in PlanetLab , and ( 3 ) our experiences tracing and analyzing three systems : CoDeeN and Coral , two content-distribution networks in PlanetLab ; and Slurpee , an enterprise-scale incident-monitoring system .
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