著者

Yuta Hirasawa Hideya Iwasaki Tomoharu Ugawa Hiro Onozawa

雑誌

情報処理学会論文誌 (ISSN:18827764)

巻号頁・発行日

vol.63, no.10, 2022-10-15

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Virtual machines (VMs) for dynamically managed languages such as JavaScript are generally implemented in C or C++. Implementation of VMs in such low-level languages offers the advantage of high flexibility, but it suffers from problems of descriptiveness and safety. These problems are due to the fact that even though a variety of VM operations are based on the VM's internal datatypes for first-class objects in the target language, the C code typically treats all VM internal datatypes as a single type in C. In addition, VMs implemented in C or C++ have a size problem which is a serious issue for VMs on embedded systems. The reason for this problem is the difficulty of eliminating unnecessary code fragments from the C code for a specific application. To solve these problems, we propose a domain-specific language for describing VM programs and a corresponding compiler to C programs, called VMDL and VMDLC, respectively. We also propose related utility tools. This framework enables generation of C source code for an eJSVM, a JavaScript VM for embedded systems. VMDL's concise syntax enables static VM datatype analysis for optimizations and error detection. We evaluated the framework and confirmed its effectiveness from both qualitative and quantitative viewpoints.------------------------------This is a preprint of an article intended for publication Journal ofInformation Processing(JIP). This preprint should not be cited. Thisarticle should be cited as: Journal of Information Processing Vol.30(2022) (online)DOI http://dx.doi.org/10.2197/ipsjjip.30.679------------------------------

著者

岩崎 英哉 Hideya Iwasaki 東京大学大学院工学系研究科情報工学 Department of Information Engineering Mathemaical Engineering University of Tokyo

雑誌

コンピュータソフトウェア = Computer software (ISSN:02896540)

巻号頁・発行日

vol.15, no.6, pp.547-560, 1998-11-16

著者

杉木 章義 河野 健二 岩崎 英哉 Akiyoshi Sugiki Kenji Kono Hideya Iwasaki 電気通信大学大学院電気通信学研究科情報工学専攻 慶應義塾大学理工学部情報工学科 電気通信大学電気通信学部情報工学科 Department of Computer Science Graduate School of Electro-Communications The University of Electro-Communications Department of Information and Computer Science Keio University Department of Computer Science The University of Electro-Communications

出版者

Japan Society for Software Science and Technology

雑誌

コンピュータソフトウェア = Computer software (ISSN:02896540)

巻号頁・発行日

vol.24, no.2, pp.68-78, 2007-04-24

参考文献数

27

被引用文献数

7

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インターネットサーバの手動による性能パラメータ調整は,多くの経験や時間を必要とし,管理コストの増大を招くことが知られている.ウェブサーバの主要な性能パラメータであるkeep-alive時間は,適切に設定しない場合,サーバのスループットや応答性を低下させることがある.本論文では,ウェブサーバのkeep-alive時間の自動設定機構を提案する.本機構は管理者の介入を必要とせず,手動設定で求めた値に近いkeep-alive時間に自動設定する.本機構はリクエスト待機間隔を監視しながら,データを送受信していない接続を切断し,データを頻繁に送受信している多くのクライアントからの接続を保つようにkeep-alive時間を設定する.本機構をApacheウェブサーバを対象としたライブラリとして実装し,実験を行った.その結果,異なる2つの負荷に対して,それぞれkeep-alive時間を自動的に設定し,サーバの性能を適切に維持することを確認した.Manual parameter-tuning of Internet servers causes high administrative costs because it requires administrator's expertise and huge amounts of time. The keep-alive parameter, which is one of major parameters in web servers, may cause severe degradation if it is not set properly. In this paper, we present an automatic tuning technique of the keep-alive parameter. Our mechanism adjusts the parameter without administrator's intervention so as to maintain active connections between clients and a server while closing inactive connections by observing request-waiting intervals. We implemented a prototype for Apache web server. Experimental results show that our prototype automatically adjusted the parameter and successfully yielded the nearly optimal server performance on two different workloads.