Dissertation•
The design of a fast and flexible internet subscription system using content graphs
01 Jan 2004-
TL;DR: The design and evaluation of the Fast, Flexible Forwarding system (F3), a distributed system for disseminating information to networked subscribers, suggest that F3 is a promising development in the area of Internet subscription systems.
Abstract: This dissertation describes the design and evaluation of the Fast, Flexible Forwarding system (F3), a distributed system for disseminating information to networked subscribers. It examines existing subscription approaches, proposes F3 as an alternative to these approaches, and presents results from comparisons of F3 and other subscription approaches.
Four studies compared performance of F3 and competing subscription systems. In the four studies, subscription systems handled such tasks as disseminating baseball scores, distributing traffic alerts, and disseminating generic subscriptions formatted as attribute-value pairs. The four studies examined system performance in both simulated network environments and on a working router. Performance characteristics examined in the studies included size of forwarding tables and processing speeds at routers.
Results from these experiments showed that F3 does not overproduce messages, as do unicast systems. F3 also outperformed single-identifier multicast systems in such areas as message production, table size, and subscription overhead. The most significant finding of the studies, however, was that F3 processing speed surpassed the speed of a state-of-the-art content-based system by orders of magnitude in scenarios with large numbers of subscribers. Overall, these results suggest that F3 is a promising development in the area of Internet subscription systems. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.) (Abstract shortened by UMI.)
Citations
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Journal Article•
TL;DR: Object-oriented abstractions for publish/subscribe interaction in the form of Distributed Asynchronous Collections (DACs) are described, which are general enough to capture the commonalities of various publish/Subscribe interaction styles, and flexible enough to allow the exploitation of the differences between these flavors.
Abstract: Publish/subscribe is considered one of the most important interaction styles for the explosive market of enterprise application integration. Producers publish information on a software bus and consumers subscribe to the information they want to receive from that bus. The decoupling nature of the interaction between the publishers and the subscribers is not only important for enterprise computing products but also for many emerging e-commerce and telecommunication applications. It is often claimed that object-orientation is inherently incompatible with the publish/subscribe interaction style. This flawed argument is due to the persistent confusion between object-orientation as a modeling discipline and the specific request/reply mechanism promoted by CORBA-like middleware systems. This paper describes object-oriented ions for publish/subscribe interaction in the form of Distributed Asynchronous Collections (DACs). DACs are general enough to capture the commonalities of various publish/subscribe interaction styles, and flexible enough to allow the exploitation of the differences between these flavors.
3 citations
References
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01 Jun 1984
TL;DR: A dynamic index structure called an R-tree is described which meets this need, and algorithms for searching and updating it are given and it is concluded that it is useful for current database systems in spatial applications.
Abstract: In order to handle spatial data efficiently, as required in computer aided design and geo-data applications, a database system needs an index mechanism that will help it retrieve data items quickly according to their spatial locations However, traditional indexing methods are not well suited to data objects of non-zero size located m multi-dimensional spaces In this paper we describe a dynamic index structure called an R-tree which meets this need, and give algorithms for searching and updating it. We present the results of a series of tests which indicate that the structure performs well, and conclude that it is useful for current database systems in spatial applications
7,336 citations
"The design of a fast and flexible i..." refers methods in this paper
...For example, the preprocessor could index the subscription table using an R-tree, and then use this R-tree to quickly look up notifications [25]....
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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
"The design of a fast and flexible i..." refers background or methods in this paper
...Researchers at the Swiss Federal Institute have developed a subscription system, called DACE, that is specifically designed to support object-oriented applications [19, 20]....
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...For example, F3 is able to support typebased interfaces, similar to the DACE system [19, 20]....
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...would assign nodes in a content graph to classes in an object-oriented hierarchy [19, 20]....
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TL;DR: On conventional PC hardware, the Click IP router achieves a maximum loss-free forwarding rate of 333,000 64-byte packets per second, demonstrating that Click's modular and flexible architecture is compatible with good performance.
Abstract: Clicks is a new software architecture for building flexible and configurable routers. A Click router is assembled from packet processing modules called elements. Individual elements implement simple router functions like packet classification, queuing, scheduling, and interfacing with network devices. A router configurable is a directed graph with elements at the vertices; packets flow along the edges of the graph. Several features make individual elements more powerful and complex configurations easier to write, including pull connections, which model packet flow drivn by transmitting hardware devices, and flow-based router context, which helps an element locate other interesting elements. Click configurations are modular and easy to extend. A standards-compliant Click IP router has 16 elements on its forwarding path; some of its elements are also useful in Ethernet switches and IP tunnelling configurations. Extending the IP router to support dropping policies, fairness among flows, or Differentiated Services simply requires adding a couple of element at the right place. On conventional PC hardware, the Click IP router achieves a maximum loss-free forwarding rate of 333,000 64-byte packets per second, demonstrating that Click's modular and flexible architecture is compatible with good performance.
2,595 citations
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01 Apr 1998
TL;DR: This memo documents version 2 of the OSPF protocol, a link-state routing protocol designed to be run internal to a single Autonomous System.
Abstract: This memo documents version 2 of the OSPF protocol. OSPF is a link-state routing protocol. It is designed to be run internal to a single Autonomous System. Each OSPF router maintains an identical database describing the Autonomous System's topology. From this database, a routing table is calculated by constructing a shortest- path tree.
2,413 citations
"The design of a fast and flexible i..." refers methods in this paper
...F3 could use a routing algorithm, such as the distance-vector algorithm used in OSPF [38], to generate routing tables....
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01 Jan 2002
TL;DR: It is found that forwarding packets via at most one intermediate RON node is sufficient to overcome faults and improve performance in most cases, demonstrating the benefits of moving some of the control over routing into the hands of end-systems.
Abstract: A Resilient Overlay Network (RON) is an architecture that allows distributed Internet applications to detect and recover from path outages and periods of degraded performance within several seconds, improving over today's wide-area routing protocols that take at least several minutes to recover. A RON is an application-layer overlay on top of the existing Internet routing substrate. The RON nodes monitor the functioning and quality of the Internet paths among themselves, and use this information to decide whether to route packets directly over the Internet or by way of other RON nodes, optimizing application-specific routing metrics.Results from two sets of measurements of a working RON deployed at sites scattered across the Internet demonstrate the benefits of our architecture. For instance, over a 64-hour sampling period in March 2001 across a twelve-node RON, there were 32 significant outages, each lasting over thirty minutes, over the 132 measured paths. RON's routing mechanism was able to detect, recover, and route around all of them, in less than twenty seconds on average, showing that its methods for fault detection and recovery work well at discovering alternate paths in the Internet. Furthermore, RON was able to improve the loss rate, latency, or throughput perceived by data transfers; for example, about 5% of the transfers doubled their TCP throughput and 5% of our transfers saw their loss probability reduced by 0.05. We found that forwarding packets via at most one intermediate RON node is sufficient to overcome faults and improve performance in most cases. These improvements, particularly in the area of fault detection and recovery, demonstrate the benefits of moving some of the control over routing into the hands of end-systems.
1,754 citations
"The design of a fast and flexible i..." refers background in this paper
...Other proposed topologies use redundant routers, network links, and multi-path routing to decrease load on individual routers and increase system resilience [4, 54]....
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