Network performance effects of HTTP/1.1, CSS1, and PNG
SIGCOMM '97 Proceedings of the ACM SIGCOMM '97 conference on Applications, technologies, architectures, and protocols for computer communication
Modeling the performance of HTTP over several transport protocols
IEEE/ACM Transactions on Networking (TON)
Managing TCP connection under persistent HTTP
WWW '99 Proceedings of the eighth international conference on World Wide Web
BLT: Bi-layer tracing of HTTP and TCP&slash;IP
Proceedings of the 9th international World Wide Web conference on Computer networks : the international journal of computer and telecommunications netowrking
A Study of Communication Delays for Web Transactions
Cluster Computing
Proactive Caching of DNS Records: Addressing a Performance Bottleneck
SAINT '01 Proceedings of the 2001 Symposium on Applications and the Internet (SAINT 2001)
Measuring client-perceived response times on the WWW
USITS'01 Proceedings of the 3rd conference on USENIX Symposium on Internet Technologies and Systems - Volume 3
Characteristics of web applications that affect usability: a review
OZCHI '05 Proceedings of the 17th Australia conference on Computer-Human Interaction: Citizens Online: Considerations for Today and the Future
The Viúva Negra crawler: an experience report
Software—Practice & Experience
Design and selection criteria for a national web archive
ECDL'06 Proceedings of the 10th European conference on Research and Advanced Technology for Digital Libraries
Advances in Human-Computer Interaction
Understanding latency variations of black box services
Proceedings of the 22nd international conference on World Wide Web
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The central performance problem in the World Wide Web, in recent years, is user perceived latency. This is the time spent by a user while waiting for a Web page he/she requested. Impatience with poor performance is the most common reason visitors terminate their visit at Web sites. For e-commerce sites, such abandonment translates into lost revenue. For this reason, measuring the delay experienced by its customers is of high importance to a Web site. These measurements are critical for analyzing the site behavior and to size its components. As of today the main tool for conducting such measurements are external, client-side tools, whereby agents located on the net request pages from the site and measure its latency. In this paper we propose a novel solution that conducts the measurements of the user perceived delay at the Web site. The major advantage of this measurement approach, as opposed to client side approach, is that it can evaluate the latency experienced by each and every client (regardless of its network location). Further, this estimate can be conducted at real time, thus allowing the server to control its operation and prioritize the requests based on the actual performance observed by the clients. The solution does not require any agents to be placed at the net. Further, it does not sniff low-level protocols (that is, IP protocols) and is all based on implementation at the HTTP level. As such, it is very efficient and economical. The solution is based on a novel technique in which a special tiny HTTP object, which is called the sentry and which is inserted at the end of the HTTP document, assists in measuring the user perceived latency. The algorithm is implemented on the Apache server. The implementation was tested throughout an extensive array of tests and found to provide very accurate measures (whose relative errors were in the order of several percents only).