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Institute of Communication Networks and Computer Engineering (IKR)
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IKR Publication No 36420 |
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Publication No 36420
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Author(s)
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Scharf, M.*
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Title
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On the Response Time of Large-scale Composite Web Services
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Methods
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Performance Evaluation; Network Planning
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Keywords
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DISTRIBUTED DATABASE; END-TO-END DELAY; HEAVY TAIL; PERFORMANCE EVALUATION; QUEUEING THEORY; WEB SERVICES
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Abstract
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This paper studies the response time of a web service middleware that decomposes requests into sub-queries to different servers and then merges the results. We present a queuing model for such a fork-join system and an exact analysis for exponential server response times. We also provide accurate approximations for heavy-tailed server response times, which are a common effect in the Internet. Heavy-tailed distributions are critical since they may cause very long middleware response times, in particular in large-scale systems with many servers being involved. We show that in this case the performance can be significantly improved if the middleware does not have to wait for a few slow servers, i. e., if the merged result does not need to be absolutely complete. We discuss different choices to implement such a mechanism and quantify their impact on the middleware response time.
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Year
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2005
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Reference entry
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Scharf, M.
On the Response Time of Large-scale Composite Web Services
Proceedings of the 19th International Teletraffic Congress (ITC 19), Beijing, August 2005
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BibTex file
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Download [BIBTEX]
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Full Text
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Download
[PDF]
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Authors marked with an asterisk (*) were IKR staff members at the time the publication has been written.
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