Bilgisayar Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1940

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Access Right: Closed AccessAuthor: search.filters.author.Göker, Turguy

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Now showing 1 - 8 of 8
  • Article
    Citation - WoS: 6
    Citation - Scopus: 9
    A Data-Assisted Reliability Model for Carrier-Assisted Cold Data Storage Systems
    (Elsevier, 2020) Arslan, Şuayb Şefik; Arslan, Şefik Şuayb; Göker, Turguy; Peng, James; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF University
    Cold data storage systems are used to allow long term digital preservation for institutions’ archive. The common functionality among cold and warm/hot data storage is that the data is stored on some physical medium for read-back at a later time. However in cold storage, write and read operations are not necessarily done in the same exact geographical location. Hence, a third party assistance is typically utilized to bring together the medium and the drive. On the other hand, the reliability modeling of such a decomposed system poses few challenges that do not necessarily exist in other warm/hot storage alternatives such as fault detection and absence of the carrier, all totaling up to the data unavailability issues. In this paper, we propose a generalized non-homogenous Markov model that encompasses the aging of the carriers in order to address the requirements of today's cold data storage systems in which the data is encoded and spread across multiple nodes for the long-term data retention. We have derived useful lower/upper bounds on the overall system availability. Furthermore, the collected field data is used to estimate parameters of a Weibull distribution to accurately predict the lifetime of the carriers in an example scale-out setting.
  • Patent
    Removable Media Based Object Store
    (2017) Wideman, Roderick; Arslan, Şuayb Şefik; Göker, Turguy
    Embodiments disclosed herein provide systems, methods, and computer-readable media to implement an object store with removable storage media. In a particular embodiment, a method provides identifying first data for storage on a first removable storage medium and designating at least a portion of the first data to a first data object. The method further provides determining a first location where to store the first data object in a first value store partition of the first remov­ able storage medium and writing the first data object to the first location. Also, the method provides writing a first key that identifies the first data object and indicates the first location to a first key store partition of the first removable storage medium.
  • Patent
    Efficient High/Low Energy Zone Solid State Device Data Storage
    (2016) Arslan, Şuayb Şefik; Göker, Turguy
    Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include circuits that produce EC encoded data that has a likelihood of use, that select a location to store the EC encoded data in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC encoded data in the loca­ tion, and that compute an order of retrieval for EC encoded data stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC encoded data may also have a priority based on the number of erasures for which the EC corrects.
  • Patent
    Power Savings in Cold Storage
    (2016) Arslan, Şuayb Şefik; Göker, Turguy
    Methods and apparatus associated with data cold storage are described. Example apparatus include an array of data storage devices arranged in rows and columns. Columns of the array are orthogonal to rows. A row has an associated row-centric power supply, and a column has an associated column-centric local electronics module (LEM) that controls a data storage device in the column independently of other data storage devices in the array. Example apparatus include logics that control a power mode of a data storage device independently of other data storage devices in the array, that control a power mode of an LEM, that adaptively regulate the level of data stored in a buffer, and that determine whether a data object will be stored in the buffer or stored on a data storage device in the array, based on the probability the data object will be accessed within a threshold period of time.
  • Patent
    High/Low Energy Zone Data Storage
    (2016) Göker, Turguy; Arslan, Şuayb Şefik
    Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include logics that produce an EC that has a likelihood of use, that select a location to store the EC in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC in the location, and that compute an order of retrieval for an EC stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC may also have a priority based on the number of erasures for which the EC corrects.
  • Patent
    Adaptive Erasure Codes
    (2017) Arslan, Şuayb Şefik; Göker, Turguy
    Methods, apparatus, and other embodiments associated with adaptive use of erasure codes for distributed data storage systems are described. One example method includes accessing a message, where the message has a message size, selecting an encoding strategy as a function of the message size, data storage device failure statistics, data storage device wear periods, data storage space constraints, or overhead constraints, and where the encoding strategy includes an erasure code approach, generating an encoded message using the encoding strategy, generating an encoded block, where the encoded block includes the encoded mes­ sage and metadata associated with the message, and storing the encoded block in the data storage system. Example methods and apparatus may employ Reed Solomon erasure codes or Fountain erasure codes. Example methods and apparatus may display to a user the storage capacity and durability of the data storage system.
  • Patent
    Data Deduplication With Adaptive Erasure Code Redundancy (us20160013815a1)
    (2016) Arslan, Şuayb Şefik; Wideman, Roderick; Lee, Jaewook; Göker, Turguy
    Example apparatus and methods combine erasure coding with data deduplication to simultaneously reduce the overall redundancy in data while increasing the redundancy of unique data. In one embodiment, an efficient representation of a data set is produced by deduplication. The efficient rep­ resentation reduces duplicate data in the data set. Redundancy is then added back into the data set using erasure coding. The redundancy that is added back in adds protection to the unique data associated with the efficient representation. How much redundancy is added back in and what type of redundancy is added back in may be controlled based on an attribute (e.g., value, reference count, symbol size, number of symbols) of the unique data. Decisions concerning how much and what type of redundancy to add back in may be adapted over time based, for example, on observations of the efficiency of the overall system.
  • Conference Object
    Citation - WoS: 3
    Citation - Scopus: 3
    A Joint Dedupe-Fountain Coded Archival Storage
    (IEEE, 2017) Arslan, Şuayb Şefik; Arslan, Şefik Şuayb; Göker, Turguy; Wideman, Rod; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF University
    An erasure-coded archival file storage system is presented using a chunk-based deduplication mechanism and fountain codes for space/time efficient operation. Unlike traditional archival storage, this proposal considers the deduplication operation together with correction coding in order to provide a reliable storage solution. The building blocks of deduplication and fountain coding processes are judiciously interleaved to present two novel ideas, reducing memory footprint with weaker hashing and dealing with the increased collisions using correction coding, and applying unequal error protection to deduplicated chunks for increased availability. The combination of these two novel ideas made the performance of the proposed system stand out. For example, it is shown to outperform one of the replication-based as well as RAID data protection schemes. The proposed system also addresses some of the fundamental challenges of today's low-cost deduplicated data storage systems such as hash collisions, disk bottleneck and RAM overflow problems, securing savings up to 90% regular RAM use.