著者

Hiroshi Mine Taku Shimosawa Soki Sakurai Tadashi Takeuchi

雑誌

研究報告システムソフトウェアとオペレーティング・システム(OS) (ISSN:21888795)

巻号頁・発行日

vol.2016-OS-137, no.14, pp.1-8, 2016-05-23

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With online video editing systems, file servers supporting standard file sharing protocol and achieving high I/O performance with real-timeness are required to reduce the overall system cost. AVFS is a file system optimized for the efficient storing and access of video files. Samba is a widely used file server application and enables client terminals to access files via a network. Since Samba is not adapted to efficiently process accesses to video files using features provided by AVFS, modifications of Samba such as the addition of deadline information to I/O requests are required to benefit from AVFS. In this paper, we propose rt-Samba, the Samba-AVFS cooperation method composed of a Samba VFS module and an I/O surrogate daemon using real-time features provided by AVFS. Using this method, I/O access performance is improved while keeping the amount of modifications in Samba low. Furthermore, the standard CIFS protocol is preserved, allowing the use of unmodified editing stations for accessing files. Evaluation results of a Linux file server implementation of our proposed method show that rt-Samba achieves 3 times higher read throughput and 1.1 times higher write throughput keeping the storage I/O stability compared to an original Samba server accessing files on Ext4.

著者

Tatsuya SATO Taku SHIMOSAWA Yosuke HIMURA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E105-B, no.11, pp.1318-1331, 2022-11-01

被引用文献数

3

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Enterprises have paid attention to consortium blockchains like Hyperledger Fabric, which is one of the most promising platforms, for efficient decentralized transactions without depending on any particular organization. A consortium blockchain-based system will be typically built across multiple organizations. In such blockchain-based systems, system operations across multiple organizations in a decentralized manner are essential to maintain the value of introducing consortium blockchains. Decentralized system operations have recently been becoming realistic with the evolution of consortium blockchains. For instance, the release of Hyperledger Fabric v2.x, in which individual operational tasks for a blockchain network, such as command execution of configuration change of channels (Fabric's sub-networks) and upgrade of chaincodes (Fabric's smart contracts), can be partially executed in a decentralized manner. However, the operations workflows also include the preceding procedure of pre-sharing, coordinating, and pre-agreeing the operational information (e.g., configuration parameters) among organizations, after which operation executions can be conducted, and this preceding procedure relies on costly manual tasks. To realize efficient decentralized operations workflows for consortium blockchain-based systems in general, we propose a decentralized inter-organizational operations method that we call Operations Smart Contract (OpsSC), which defines an operations workflow as a smart contract. Furthermore, we design and implement OpsSC for blockchain network operations with Hyperledger Fabric v2.x. This paper presents OpsSC for operating channels and chaincodes, which are essential for managing the blockchain networks, through clarifying detailed workflows of those operations. A cost evaluation based on an estimation model shows that the total operational cost for executing a typical operational scenario to add an organization to a blockchain network having ten organizations could be reduced by 54 percent compared with a conventional script-based method. The implementation of OpsSC has been open-sourced and registered as one of Hyperledger Labs projects, which hosts experimental projects approved by Hyperledger.