Composition of web services is one of the flexible and easiest approaches for
creating composite services that fulfill complex tasks. Together with providing
convenience in creation of new software applications, service composition has
various challenges. One of them is the satisfaction of user-defined Quality of Service
(QoS) requirements while selecting services for a composition. Load balancing issue
is another challenge as uncontrolled workload may lead to violation of service
providers&rsquo / QoS declarations. This thesis work proposes a QoS aware method for
optimum service composition while taking into account load balancing. M/M/C
queuing model is utilized for the individual services to determine sojourn time
distribution for possible compositions. Percentile of the execution time, price and
availability are considered as QoS parameters. Proposed algorithm selects the
optimum composition according to QoS constraints and utility provided by the
services. The performance of the method is evaluated by custom simulation software
and is compared to two other methods, random selection and average execution timebased
optimal service selection.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12614369/index.pdf |
| Date | 01 June 2012 |
| Creators | Abdyldaeva, Rahat |
| Contributors | Betin Can, Aysu |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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