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Proceedings ArticleDOI

On performance improvement issues in unordered Tuple Space based Mobile Middleware

TL;DR: LIMONE's tuple-antituple structure is modified for improving its performance and scalability, both original and modified models are analyzed and experimented to show the improvements.
Abstract: Tuple Space based Mobile Middleware (TSMM), a new genre of mobile middleware, is developed to tackle emerging dynamics in underlying infrastructure. It uses tuple space model to coordinate interactions between different active components (agents) of supported applications. This paper focusses on a primary design issue of tuple space model, viz. tuple-antituple structure, which specifies arities and nature of arrangements of constituent fields of tuples and antituples. This factor not only affects application design, but also impacts simplicity, flexibility, scalability and performance of TSMM. Broadly, two types of arrangements are possible: ordered (where arity and arrangement of fields are predefined), and unordered (where none of them are predefined). Ordered structure lacks flexibility and restricts the design of TSMM and its applications. Unordered structure removes these drawbacks, but degrades TSMM's performance and scalability, as additional creation and lookup overheads are introduced here. Among the existing TSMM, LIMONE incorporates unordered tuple-antituple structure. In this paper, we modify LIMONE's tuple-antituple structure for improving its performance and scalability. Both original and modified models are analyzed and experimented to show the improvements.
Citations
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Proceedings ArticleDOI
25 Jun 2012
TL;DR: This paper proposes an improved reactive tuple space model for TSMM with enhanced decoupling behavior of reactions to achieve robustness for supported applications.
Abstract: Tuple Space based Mobile Middleware (TSMM) is developed to tackle emerging dynamics in underlying infrastructure. Its coordination medium, viz. tuple space model, has multiple inherent decoupled behaviors to coordinate interactions between different agents of supported applications. This paper focuses on one such decoupling quality, synchronization decoupling, by which agents are decoupled from their invoked primitives. This decoupling ability is accomplished by including reactivity in tuple space model. Reactive tuple space model also enables development of robust and flexible applications for TSMM. However, in existing TSMM, this decoupling behavior has not been fully attained, as reactions are themselves coupled with invoked primitives, leading to additional network and processing overheads. This paper proposes an improved reactive tuple space model for TSMM with enhanced decoupling behavior of reactions to achieve robustness for supported applications. Proposed tuple space model is also formally modeled and verified by notation and proof logic of UNITY model.

11 citations


Cites background from "On performance improvement issues i..."

  • ...Each index table is a list holding a set of indices of tuples in tuple store, which contains at least one constituent field having name or type identical/polymorphically-related to table name....

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  • ...UNITY and Mobile UNITY are state-based notation systems with suitable axiomatic reasoning, to capture essence of distributed and mobile computing paradigms respectively, and assist in developing applications in these paradigms....

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Proceedings ArticleDOI
01 Dec 2012
TL;DR: Tuple space model with proposed tuple space structure not only preserves the ease of developing mobile applications, but also facilitates performance gain during their execution.
Abstract: Tuple space model is a simple and efficient data-driven coordination model, suitable for different mobile middleware platforms. A significant performance factor of this model is tuple space structure. Existing tuple space models have sequential tuple space structure, which works efficiently with tuple-producing primitives. But, tuple-reading and -consuming primitives that drive overall performance of tuple space model, generate substantial overhead with this sequential structure. In this paper, we propose an efficient tuple space structure, which is not only simple, but also improves performance and scalability of tuple space model. We have compared proposed structure with existing ones to show the improvements. Tuple space model with proposed tuple space structure not only preserves the ease of developing mobile applications, but also facilitates performance gain during their execution.

7 citations


Cites background or methods from "On performance improvement issues i..."

  • ...Trouble worsens when tuple/antituple structure becomes unordered [10]–[14], where arity, constituent fields of tuples/antituples, and arrangement pattern these fields vary within a tuple space....

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  • ...For the proposal, we consider unordered tuple/anitutple structure given in [14], as it not only improves performance and scalability of tuple space model, but also reduces its space complexity....

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  • ...) follows a sequential structure having a space complexity of O(mn) [14], where m = number of tuples in tuple space and n = average tuple arity....

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  • ...Tuple store has a space complexity of 2mn + c for storing m tuples having average arity n, where c is constant [14]....

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Journal ArticleDOI
TL;DR: This paper proposes two enhancements in the tuple space model for TSMM: 1 enhancement in the unordered tuple/antituple structure for reducing the additional overhead as well as preserving the simplicity and flexibility of TSMM; and, 2 introduction of the enhanced tuple space structure for further reducing the overhead of the tuple-reading and -consuming primitives.
Abstract: Tuple space-based mobile middleware TSMM is affected by two elementary factors of the tuple space model, viz. the tuple/antituple structure and the tuple space structure. The tuple/antituple structure influences application design as well as simplicity and flexibility of TSMM, while the tuple space structure regulates its performance and scalability. In existing TSMM, the unordered tuple/antituple structure improves simplicity and flexibility, while degrades performance and scalability due to the additional overhead in tuple generation and lookup. Again, the sequential tuple space structure in existing TSMM produces considerable performance overhead for the tuple-reading and -consuming primitives. This paper proposes two enhancements in the tuple space model for TSMM: 1 enhancement in the unordered tuple/antituple structure for reducing the additional overhead as well as preserving the simplicity and flexibility of TSMM; and, 2 introduction of the enhanced tuple space structure for further reducing the overhead of the tuple-reading and -consuming primitives. Analysis and experiments confirm the superiority of TSMM with proposed enhancements over existing ones.

7 citations


Cites background from "On performance improvement issues i..."

  • ...Expected time of each tuple-antituple matching operation is ˆ ( ) O nn′ (De et al., 2010), where n′ is the antituple’s arity....

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  • ...The sequential tuple space structure in these TSMM has a space complexity of ˆ ( ) O mn (De et al., 2010), where m = the number of tuples in the tuple space, and n̂ = the average tuple arity....

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Proceedings ArticleDOI
29 Jul 2013
TL;DR: A new architecture of mobile cloud computing, where interactions between mobile applications and cloud services will be decoupled is proposed in this paper and Tuple space model is used for uncoupling these interactions in proposed architecture, improving flexibility and efficiency ofMobile cloud computing to a great extent.
Abstract: Mobile Cloud Computing widens the service of existing facility of cloud computing paradigm to user applications executing in mobile/portable devices, called mobile applications. It enables existing cloud services to serve these applications, thereby helps to overcome the inherent limitations of mobile$/$portable devices. However, the use of cloud services in existing architecture require tight coupling between mobile applications and cloud services, which is highly undesirable in dynamic and unreliable mobile cloud computing. A new architecture of mobile cloud computing, where interactions between mobile applications and cloud services will be decoupled, is proposed in this paper. Tuple space model is used for uncoupling these interactions in proposed architecture, improving flexibility and efficiency of mobile cloud computing to a great extent. This paper also suggests an approach of formalizing proposed architecture to depict the uncoupling of service access and delivery to mobile applications. Formalization is carried out using Mobile UNITY.

6 citations


Cites background from "On performance improvement issues i..."

  • ...Both tuple and antituple structures in these tuple spaces are unordered in nature [9]....

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01 Dec 2004
TL;DR: Limone as discussed by the authors is a new coordination model that facilitates rapid application development over ad hoc networks consisting of logically mobile agents and physically mobile hosts, allowing each agent to define its own acquaintance policy and limiting all agent-initiated interactions to agents that satisfy the policy.
Abstract: This paper presents Limone, a new coordination model that facilitates rapid application development over ad hoc networks consisting of logically mobile agents and physically mobile hosts. Limone assumes an agent-centric perspective on coordination by allowing each agent to define its own acquaintance policy and by limiting all agent-initiated interactions to agents that satisfy the policy. Agents that satisfy this acquaintance policy are stored in an acquaintance list, which is automatically maintained by the system. This asymmetric style of coordination allows each agent to focus on relevant peers. Coordination activities are restricted to tuple spaces owned by agents in the acquaintance list. Limone tailors Linda-like primitives for mobile environments by eliminating remote blocking and complex group operations. It also provides timeouts for all distributed operations and reactions that enable asynchronous communication with agents in the acquaintance list. Finally, Limone minimizes the granularity of atomic operations and the set of assumptions about the environment. In this paper we introduce Limone, explain its key features, and explore its capabilities as a coordination model. A universal remote control implementation using Limone provides a concrete illustration of the model and the applications it can support.

5 citations

References
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Journal ArticleDOI
TL;DR: This paper factors out the common denominator underlying these variants: full decoupling of the communicating entities in time, space, and synchronization to better identify commonalities and divergences with traditional interaction paradigms.
Abstract: Well adapted to the loosely coupled nature of distributed interaction in large-scale applications, the publish/subscribe communication paradigm has recently received increasing attention. With systems based on the publish/subscribe interaction scheme, subscribers register their interest in an event, or a pattern of events, and are subsequently asynchronously notified of events generated by publishers. Many variants of the paradigm have recently been proposed, each variant being specifically adapted to some given application or network model. This paper factors out the common denominator underlying these variants: full decoupling of the communicating entities in time, space, and synchronization. We use these three decoupling dimensions to better identify commonalities and divergences with traditional interaction paradigms. The many variations on the theme of publish/subscribe are classified and synthesized. In particular, their respective benefits and shortcomings are discussed both in terms of interfaces and implementations.

3,380 citations


Additional excerpts

  • ...asynchronous, anonymous, generative, associative and agent-decoupled communications [7], [8]....

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Journal ArticleDOI
David Gelernter1
TL;DR: This work is particularly concerned with implementation of the dynamic global name space that the generative communication model requires, and its implications for systems programming in distributed settings generally and on integrated network computers in particular.
Abstract: Generative communication is the basis of a new distributed programming langauge that is intended for systems programming in distributed settings generally and on integrated network computers in particular. It differs from previous interprocess communication models in specifying that messages be added in tuple-structured form to the computation environment, where they exist as named, independent entities until some process chooses to receive them. Generative communication results in a number of distinguishing properties in the new language, Linda, that is built around it. Linda is fully distributed in space and distributed in time; it allows distributed sharing, continuation passing, and structured naming. We discuss these properties and their implications, then give a series of examples. Linda presents novel implementation problems that we discuss in Part II. We are particularly concerned with implementation of the dynamic global name space that the generative communication model requires.

2,584 citations


"On performance improvement issues i..." refers background in this paper

  • ...), tuple space model [5], [6] supports multiple inherent decoupled behaviors, viz....

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Journal ArticleDOI
TL;DR: How can a system that differs sharply from all currently fashionable approaches score any kind of success?
Abstract: How can a system that differs sharply from all currently fashionable approaches score any kind of success? Here's how.

1,537 citations


"On performance improvement issues i..." refers background in this paper

  • ...), tuple space model [5], [6] supports multiple inherent decoupled behaviors, viz....

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Journal ArticleDOI
01 May 2004
TL;DR: In this paper, a simple dictionary with worst case constant lookup time was presented, equaling the theoretical performance of the classic dynamic perfect hashing scheme of Dietzfelbinger et al.
Abstract: We present a simple dictionary with worst case constant lookup time, equaling the theoretical performance of the classic dynamic perfect hashing scheme of Dietzfelbinger et al. [SIAM J. Comput. 23 (4) (1994) 738-761]. The space usage is similar to that of binary search trees. Besides being conceptually much simpler than previous dynamic dictionaries with worst case constant lookup time, our data structure is interesting in that it does not use perfect hashing, but rather a variant of open addressing where keys can be moved back in their probe sequences. An implementation inspired by our algorithm, but using weaker hash functions, is found to be quite practical. It is competitive with the best known dictionaries having an average case (but no nontrivial worst case) guarantee on lookup time.

963 citations

Book
30 May 1997

581 citations