Showing papers on "Server published in 2000"

OceanStore: an architecture for global-scale persistent storage

Abstract: OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development.

Practical techniques for searches on encrypted data

Abstract: It is desirable to store data on data storage servers such as mail servers and file servers in encrypted form to reduce security and privacy risks. But this usually implies that one has to sacrifice functionality for security. For example, if a client wishes to retrieve only documents containing certain words, it was not previously known how to let the data storage server perform the search and answer the query, without loss of data confidentiality. We describe our cryptographic schemes for the problem of searching on encrypted data and provide proofs of security for the resulting crypto systems. Our techniques have a number of crucial advantages. They are provably secure: they provide provable secrecy for encryption, in the sense that the untrusted server cannot learn anything about the plaintext when only given the ciphertext; they provide query isolation for searches, meaning that the untrusted server cannot learn anything more about the plaintext than the search result; they provide controlled searching, so that the untrusted server cannot search for an arbitrary word without the user's authorization; they also support hidden queries, so that the user may ask the untrusted server to search for a secret word without revealing the word to the server. The algorithms presented are simple, fast (for a document of length n, the encryption and search algorithms only need O(n) stream cipher and block cipher operations), and introduce almost no space and communication overhead, and hence are practical to use today.

Computer-based communication system and method using metadata defining a control-structure

Abstract: An automated communications system operates to transfer data, metadata and methods from a provider computer to a consumer computer through a communications network. The transferred information controls the communications relationship, including responses by the consumer computer, updating of information, and processes for future communications. Information which changes in the provider computer is automatically updated in the consumer computer through the communications system in order to maintain continuity of the relationship. Transfer of metadata and methods permits intelligent processing of information by the consumer computer and combined control by the provider and consumer of the types and content of information subsequently transferred. Object oriented processing is used for storage and transfer of information. The use of metadata and methods further allows for automating may of the actions underlying the communications, including communication acknowledgements and archiving of information. Service objects and partner servers provide specialized data, metadata, and methods to providers and consumers to automate many common communications services and transactions useful to both providers and consumers. A combination of the provider and consumer programs and databases allows for additional functionality, including coordination of multiple users for a single database.

A scalable location service for geographic ad hoc routing

Abstract: GLS is a new distributed location service which tracks mobile node locations. GLS combined with geographic forwarding allows the construction of ad hoc mobile networks that scale to a larger number of nodes than possible with previous work. GLS is decentralized and runs on the mobile nodes themselves, requiring no fixed infrastructure. Each mobile node periodically updates a small set of other nodes (its location servers) with its current location. A node sends its position updates to its location servers without knowing their actual identities, assisted by a predefined ordering of node identifiers and a predefined geographic hierarchy. Queries for a mobile node's location also use the predefined identifier ordering and spatial hierarchy to find a location server for that node.Experiments using the ns simulator for up to 600 mobile nodes show that the storage and bandwidth requirements of GLS grow slowly with the size of the network. Furthermore, GLS tolerates node failures well: each failure has only a limited effect and query performance degrades gracefully as nodes fail and restart. The query performance of GLS is also relatively insensitive to node speeds. Simple geographic forwarding combined with GLS compares favorably with Dynamic Source Routing (DSR): in larger networks (over 200 nodes) our approach delivers more packets, but consumes fewer network resources.

Web Based Knowledge Infrastructures for the Sciences: An Adaptive Document

Abstract: Scientific knowledge is increasingly being stored online. A large number of infrastructures that provide access to scientific knowledge are now available on the Internet. They range from online journals to collaboratories and logic servers. This article examines a variety of such infrastructures and derives implications for their further evolution. It assesses their impact on the way that scientists will create, organize and integrate knowledge. In parallel, the article illustrates how online content may become more adaptive and structured. The text consists of individually marked sections that are assembled dynamically to the needs of each reader on different levels of detail.

System and method for voice transmission over network protocols

Abstract: A system and method for voice transmission over high level network protocols. On the Internet and the World Wide Web, such high level protocols are HTTP/TCP. The restrictions imposed by firewalls and proxy servers are avoided by using HTTP level connections to transmit voice data. In addition, packet delivery guarantees are obtained by using TCP instead of UDP. Variable compression based on silence detection takes advantage of the natural silences and pauses in human speech, thus reducing the delays in transmission caused by using HTTP/TCP. The silence detection includes the ability to bookend the voice data sent with small portions of silence to insure that the voice sounds natural. Finally, the voice data is transmitted to each client computer independently from a common circular list of voice data, thus insuring that all clients will stay current with the most recent voice data. The combination of these features enables simple, seamless, and interactive Internet conferencing.

Distributed system to intelligently establish sessions between anonymous users over various networks

Abstract: A network provides users with a simple and secure way of establishing communication sessions with other users or services, running either over IP networks or other networks, e.g., PSTN. In a sense, the network can broker communication services between two or more users (e.g., people) and/or services. A plurality of different clusters of servers is provided, and each of the clusters may be linked together. In certain embodiments, each cluster includes multiple servers. Users are registered within some specific cluster and given a unique system/network ID. In certain embodiments, messages are not sent directly between users, but instead through at least one intermediate routing service (RS) provided on a server of one of the users. Thus, in certain embodiments, a user may hide or mask his/her personal information from other users even when communicating with them. In certain embodiments, a user may establish a communication session with another user without knowledge of the client device (e.g., PC, mobile phone, etc.) being used by the other user; as the network arranges for communication (e.g., text chat session, voice chat session (PC to PC, PC to PSTN, or PC to mobile phone), web conference, or pages (PC to PC, PC to SMS)) between the users regardless of the client device being used by the called user. Thus, the network enables any of the above communication services between users, and the initiating user need not know whether the other user is currently online via his/her PC or may instead be reached via pager or mobile phone.

Multimedia surveillance and monitoring system including network configuration

Abstract: A comprehensive, wireless multimedia surveillance and monitoring system provides a combination of megapixel digital camera capability with full motion video surveillance with a network, including network components and appliances such as wiring, workstations, and servers with the option of geographical distribution with various wide area carriers. The full service, multi-media surveillance system is capable of a wide range of monitoring techniques utilizing digital network architecture and is adapted for transmitting event data, video and/or image monitoring information, audio signals and other sensor and detector data over significant distances using digital data transmission over a LAN, wireless LAN, Intranet or Internet for automatic assessment and response including dispatch of response personnel. Both wired and wireless appliance and sensor systems may be employed. GPS dispatching is used to locate and alert personnel as well as to indicate the location of an event. Automatic mapping and dispatch permits rapid response. The wireless LAN connectivity permits local distribution of audio, video and image data over a relatively high bandwidth without requirement of a license and without relying on a common carrier and the fees associated therewith. The surveillance system may be interfaced with a WAN (wide area Network) or the Internet for providing a worldwide, low cost surveillance system with virtually unlimited geographic application. Centralized monitoring stations have access to all of the surveillance data from various remote locations via the Internet or the WAN. A server provides a centralized location for data collection, alarm detection and processing, access control, dispatch processing, logging functions and other specialized functions. The server may be inserted virtually anywhere in the Intranet/Internet network. The topology of the network will be established by the geographic situation of the installation. Appropriate firewalls may be set up as desired. The server based system permits a security provider to have access to the appliance and sensor and surveillance data or to configure or reconfigure the system for any station on the network.

The Jalapeño virtual machine

Abstract: Jalapeno is a virtual machine for JavaTM servers written in the Java language. To be able to address the requirements of servers (performance and scalability in particular), Jalapeno was designed "from scratch" to be as self-sufficient as possible. Jalapeno's unique object model and memory layout allows a hardware null-pointer check as well as fast access to array elements, fields, and methods. Run-time services conventionally provided in native code are implemented primarily in Java. Java threads are multiplexed by virtual processors (implemented as operating system threads). A family of concurrent object allocators and parallel type-accurate garbage collectors is supported. Jalapeno's interoperable compilers enable quasi-preemptive thread switching and precise location of object references. Jalapeno's dynamic optimizing compiler is designed to obtain high quality code for methods that are observed to be frequently executed or computationally intensive.

System for electronic barter, trading and redeeming points accumulated in frequent use reward programs

Abstract: not available for EP1224587Abstract of corresponding document: WO0079461A system and method for operating a reward points accumulation and redemption program wherein a user earns reward points from a plurality of reward points issuing entities, each of the reward points issuing entities tracking the user's earned reward points in a user reward point account stored on a rewards server. A trading server accumulates the user's earned reward points from each of the reward servers (10, 12, 14) interconnected over a network in association with consideration provided by the reward servers to the trading server (20) and credits the accumulated points into a reward exchange account associated with the user (40). The user may then select an item for purchase from a merchant computer (30) interconnected to the network. The merchant computer provides the item to the user in exchange for consideration received from the trading server.

Hoard: a scalable memory allocator for multithreaded applications

Abstract: Parallel, multithreaded C and C++ programs such as web servers, database managers, news servers, and scientific applications are becoming increasingly prevalent. For these applications, the memory allocator is often a bottleneck that severely limits program performance and scalability on multiprocessor systems. Previous allocators suffer from problems that include poor performance and scalability, and heap organizations that introduce false sharing. Worse, many allocators exhibit a dramatic increase in memory consumption when confronted with a producer-consumer pattern of object allocation and freeing. This increase in memory consumption can range from a factor of P (the number of processors) to unbounded memory consumption.This paper introduces Hoard, a fast, highly scalable allocator that largely avoids false sharing and is memory efficient. Hoard is the first allocator to simultaneously solve the above problems. Hoard combines one global heap and per-processor heaps with a novel discipline that provably bounds memory consumption and has very low synchronization costs in the common case. Our results on eleven programs demonstrate that Hoard yields low average fragmentation and improves overall program performance over the standard Solaris allocator by up to a factor of 60 on 14 processors, and up to a factor of 18 over the next best allocator we tested.

System and method for sending live video on the internet

Abstract: An Internet-based video feed management system controls, manages, and efficiently administers the commercial distribution of live video feeds from on-site video cameras as well as other sources of video feeds to production companies at other locations. The system employs a network of local video-propagation servers located in different localities for receiving the video feeds from the different source locations, and a master authorization server for receiving and granting requests via Internet from requesting parties for access to any of the video feeds transmitted to the video-propagation servers. The master server issues an access code to the requesting party and establishing a unique publishing point for the requested video feed from the video-propagation server handling the feed. The on-site video cameras can supply live video feeds to the requesting parties, or the video feeds can be transmitted to a video-propagation server for storage and later re-transmission. The master server is provided with a master feed list and a pricing table for computing billings to requesting parties, and payments to sources of video feeds. The master feed list is updated by feed listings input to the video-propagation servers. For live video feeds captured by different types of video cameras at the on-site locations, the system allows a requesting party to access the video camera for remote control on the Internet. An universal control panel GUI is provided for the browser of the requesting party, and is used to issue command codes corresponding to the respective video camera type. The system can be used to automatically generate video Web pages hosted on the master server and linked to the clients' Web sites. The master server allows the client to select from different display templates, and to upload their identification graphics for incorporation into the display template with the desired video feed, thereby obtaining a marked reduction in production costs for creating video Web pages for e-commerce, live events programming, etc.

Access control meets public key infrastructure, or: assigning roles to strangers

Abstract: The Internet enables connectivity between many strangers: entities that don't know each other. We present the Trust Policy Language (TPL), used to define the mapping of strangers to predefined business roles, based on certificates issued by third parties. TPL is expressive enough to allow complex policies, e.g. non-monotone (negative) certificates, while being simple enough to allow automated policy checking and processing. Issuers of certificates are either known in advance, or provide sufficient certificates to be considered a trusted authority according to the policy. This allows bottom-up, "grass roots" buildup of trust, as in the real world. We extend, rather than replace, existing role based access control mechanisms. This provides a simple, modular architecture and easy migration from existing systems. Our system automatically collects missing certificates from peer servers. In particular this allows use of standard browsers, which pass only one certificate to the server. We describe our implementation, which can be used as an extension of a Web server or as a separate server with interface to applications.

System and method for providing interactive dialogue and iterative search functions to find information

Abstract: A system and method for information searching comprising determination of, in fine granularity, a Community of Interest (COI), further data mining in search results, using at least one of COI and expert preferences to identify important knowledge, formulation and manipulation of results, and summarization of search results into a document like entity with dynamic attributes described. More particularly, the invention relates to a system and method for providing interactive dialogue and iterative search functions to find information on a large network of servers such as the world wide web.

A scalable approach to thread-level speculation

Abstract: While architects understand how to build cost-effective parallel machines across a wide spectrum of machine sizes (ranging from within a single chip to large-scale servers), the real challenge is how to easily create parallel software to effectively exploit all of this raw performance potential. One promising technique for overcoming this problem is Thread-Level Speculation (TLS), which enables the compiler to optimistically create parallel threads despite uncertainty as to whether those threads are actually independent. In this paper, we propose and evaluate a design for supporting TLS that seamlessly scales to any machine size because it is a straightforward extension of writeback invalidation-based cache coherence (which itself scales both up and down). Our experimental results demonstrate that our scheme performs well on both single-chip multiprocessors and on larger-scale machines where communication latencies are twenty times larger.

Proximity-based redirection system for robust and scalable service-node location in an internetwork

Abstract: A proximity-oriented redirection system for service-to-client attachment in a virtual overlay distribution network. The virtual overlay distribution network includes addressable routers for routing packet traffic, wherein a packet of data is routed from a source node to a destination node based on address fields of the packet. The invention includes a redirector coupled to at least one of the addressable routers and includes: logic for accepting a service request from a client; logic for determining a selected server for handling the service request, the selected server being one of a plurality of servers that can handle the service request; and logic for generating a redirection message directed to the client for redirecting the service request to the selected server.

System and method of using machine-readable or human-readable linkage codes for accessing networked data resources

Abstract: A method and system for providing a primary content file to a client computer (20) that is interconnected over a computer network (16) with an information server computer (50), a routing server computer (40), a content server computer (60), and a registration server computer (30). The present invention operates by inputting into the client computer a linkage code (10) (a machine readable code such as a bar code symbol (104) or a human-readable alphanumeric text string (106)) that includes a server identification code (110) and an item identification code (112). The client computer then extracts the server identification code, and obtains from local cache (27) or from the routing server a URL template associated with the server identification code. The URL template includes the name of an information server and at least one parameter field to be completed by the client computer. The URL template is completed by the client computer by filling in at least the item identification code, and the completed URL template is then sent to the information server named therein as a primary content URL request. At the information server, the location of the primary content file is determined based on the item identification code, and the information server provides the client computer with the primary content file by either redirecting it to the primary content server computer or obtaining it from local storage.

System and method for integrated load-distribution and resource management on internet environment

Abstract: A system providing access to web objects that matches predicted demand for web objects to available capacity on web servers. The system implements methods to dynamically shape both demand and capacity based on certain criteria. The system provides methods to dynamically shape demand for an object based on criteria such as arrival time, incoming geography, and costs requirements. In particular, the present invention characterizes future demand for an object based on aggregation and forecasting of past demand for such object. The system effectively permits control and customization of capacity across one or more media servers based on characteristics associated with the demand across one or more of them, and particularly, based on the dominating geographical traits of past demand. Moreover, the system dynamically shapes capacity by: (a) controlling the number of replicas associated with an object; and, (b) controlling the placement of these replicas across servers in a distributed network. In particular, the system drives capacity shaping measures over a particular object based on its predicted demand. Consequently, the number and location of replicas associated with an object is made to be variable over time and driven by predicted demand for a web object.

The Free Haven Project: Distributed Anonymous Storage Service.

Abstract: We present a design for a system of anonymous storage which resists the attempts of powerful adversaries to find or destroy any stored data. We enumerate distinct notions of anonymity for each party in the system, and suggest a way to classify anonymous systems based on the kinds of anonymity provided. Our design ensures the availability of each document for a publisher-specified lifetime. A reputation system provides server accountability by limiting the damage caused from misbehaving servers. We identify attacks and defenses against anonymous storage services, and close with a list of problems which are currently unsolved.

Secure wireless electronic-commerce system with digital product certificates and digital license certificates

Abstract: A wireless electronic commerce system (10) comprising a wireless gateway (18) to a wireless network (19) with which a wireless device (11) having a unique client identifier (ID) is capable of communicating. A server (15) or servers (15 and 16) is/are coupleable to the wireless gateway, delivering content items (e.g. software products) to the wireless device (11) and maintaining digital content certificates for content items and digital license certificates for licenses for the content items. The server maintains, for each wireless client associated with the system, a record of licenses for that client and a record of content items associated with each license.

System, method, and program for ranking search results using user category weighting

Abstract: In a system, method and program for ordering search results of files available over a network, search results obtained by a search engine server may be ranked by associating user category weights with each file indexed in a search database. Search results may be provided to a user ranked in accordance with one or more user categories. The search results may augment additional search results ranked in accordance with additional ranking criteria. A system for implementing the ranking of search results may include a search engine server. The search engine server may interface with a plurality of network clients and information content servers. The search engine server may include one or more storage devices containing program instructions and data to perform the methods described herein. The program instructions and data may be included on a carrier medium, which may be a transmission medium or a storage medium.

Automatically Extracting Structure from Free Text Addresses.

Abstract: Wide-area distribution raises significant performance problems for traditional query processing techniques as data access becomes less predictable due to link congestion, load imbalances, and temporary outages. Pipelined query execution is a promising approach to coping with unpredictability in such environments as it allows scheduling to adjust to the arrival properties of the data. We have developed a non-blocking join operator, called XJoin, which has a small memory footprint, allowing many such operators to be active in parallel. XJoin is optimized to produce initial results quickly and can hide intermittent delays in data arrival by reactively scheduling background processing. We show that XJoin is an effective solution for providing fast query responses to users even in the presence of slow and bursty remote sources. 1 Wide-Area Query Processing The explosive growth of the Internet and the World Wide Web has made tremendous amounts of data available on-line. Emerging standards such as XML, combined with wrapper technologies address semantic challenges by providing relational-style interfaces to remote data. Beyond the issues of structure and semantics, however, there remain significant technical obstacles to building responsive, usable query processing systems for widearea environments. A key performance issue that arises in such environments is response-time unpredictability. Data access over wide-area networks involves a large number of remote data sources, intermediate sites, and communications links, all of which are vulnerable to overloading, congestion, and failures. Such problems can cause significant and unpredictable delays in the access of information from remote sources. These delays, in turn, cause traditional distributed query processing strategies to break down, resulting in unresponsive and hence, unusable systems. In previous work [AFTU96] we identified three classes of delays that can affect the responsiveness of query processing: 1) initial delay, in which there is a longer than expected wait until the first tuple arrives from a remote source; 2) slow delivery, in which data arrive at a fairly constant but slower than expected rate; and 3) bursty arrival, in which data arrive in a fluctuating manner. With traditional query processing techniques, query execution can become blocked even if only one of the accessed data sources experiences such delays. Copyright 2000 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Bulletin of the IEEE Computer Society Technical Committee on Data Engineering This work was partially supported by the NSF under grant IRI-94-09575, by the Office of Naval Research under contract number N66001-97-C8539 (DARPA order number F475), by a Siemens Faculty Development Award, and by an IBM Partnership Award.

New multiparty authentication services and key agreement protocols

Abstract: Many modern computing environments involve dynamic peer groups. Distributed simulation, multiuser games, conferencing applications, and replicated servers are just a few examples. Given the openness of today's networks, communication among peers (group members) must be secure and, at the same time, efficient. This paper studies the problem of authenticated key agreement in dynamic peer groups with the emphasis on efficient and provably secure key authentication, key confirmation, and integrity. It begins by considering two-party authenticated key agreement and extends the results to group Diffie-Hellman (1976) key agreement. In the process, some new security properties (unique to groups) are encountered and discussed.

Real time vehicle guidance and forecasting system under traffic jam conditions

Abstract: A system and method for real time vehicle guidance by Central Traffic Unit are presented. The proposed vehicle Guidance System includes a plurality of vehicles equipped with Individual Mobile Units including GPS units (position determining systems adapted to determine their present position) and communicatively linked to the Central Traffic Unit computer server. The Central Traffic Unit broadcasts the updated traffic patterns in real time thereby enabling the Individual Mobile Units to dynamically calculate the desired optimal travel paths. In response to a request from a driver for a route update from his present position to a desired destination, the Individual Mobile Unit searches for an optimal (usually fastest) route and shows it to the driver. In route searching by the minimal time criterion, the Individual Mobile Unit relies on estimated travel times stored in its database, and may also use current real time information on bottleneck situations received from Central Traffic Unit. The forecasting system allows the driver to enter alternative time schedules for the same destination and receive alternative travel time estimates for the same destination depending on the estimated traffic volumes on the roads at that particular time. The backbone of the system is a group of Sample Mobile Units equipped with RF transmitters that communicate their present position to the Central Traffic Unit at predetermined time intervals. The Central Traffic Unit uses those sample vehicles as antennas by tracking their positions for creating and maintaining a network of real time traffic load disposition in various geographical areas. To be able to detect a bottleneck situation when it arises and to estimate a current travel time for a corresponding section of road, the Central Traffic Unit maintains a list of sample vehicles that recently exited that section. If the times those vehicles have spent on the section differ considerably from a regular time stored in the database, Central Traffic Unit uses statistical tools for forecasting the future travel time along this section. Simultaneously, the Central Traffic Unit broadcasts updated travel times and any new information on current traffic jams and slow-down bottleneck situations in a given geographical location.

Distributed server cluster for controlling network traffic

Abstract: A scalable, distributed, highly available, load balancing server system having multiple machines is provided that functions as a front server layer between a network (such as the Internet) and a back-end server layer having multiple machines functioning as Web file servers, FTP servers, or other application servers. The front layer machines comprise a server cluster that performs fail-over and dynamic load balancing for both server layers. The operation of the servers on both layers is monitored, and when a server failure at either layer is detected, the system automatically shifts network traffic from the failed machine to one or more operational machines, reconfiguring front-layer servers as needed without interrupting operation of the server system. The server system automatically accommodates additional machines in the server cluster, without service interruption. The system operates with a dynamic reconfiguration protocol that permits reassignment of network addresses to the front layer machines. The front layer machines perform their operations without breaking network communications between clients and servers, and without rebooting of computers.

Scheme for information delivery to mobile computers using cache servers

Abstract: In the disclosed information delivery scheme for delivering WWW information provided by information servers on the Internet to mobile computers connected to the Internet through a wireless network, a plurality of cache servers capable of caching WWW information provided by the information servers are provided in association with the wireless network. The cache servers can be managed by receiving a message indicating at least a connected location of a mobile computer in the wireless network from the mobile computer, selecting one or more cache servers located nearby the mobile computer according to the message, and controlling these one or more cache servers to cache selected WWW information selected for the mobile computer, so as to enable faster accesses to the selected WWW information by the mobile computer. Also, the cache servers can be managed by selecting one or more cache servers located within a geographic range defined for an information provider who provides WWW information from an information server, and controlling these one or more cache servers to cache selected WWW information selected for the information provider, so as to enable faster accesses to the selected WWW information by the mobile computer.

Distributed server cluster with graphical user interface

Abstract: A scalable, distributed, highly available, load balancing server system having multiple machines is provided that functions as a front server layer between a network (such as the Internet) and a back-end server layer having multiple machines functioning as Web file servers, FTP servers, or other application servers. The front layer machines comprise a server cluster that performs fail-over and dynamic load balancing for both server layers. The operation of the servers on both layers is monitored, and when a server failure at either layer is detected, the system automatically shifts network traffic from the failed machine to one or more operational machines, reconfiguring front-layer servers as needed without interrupting operation of the server system. The server system automatically accommodates additional machines in the server cluster, without service interruption. The system operates with a dynamic reconfiguration protocol that permits reassignment of network addresses to the front layer machines. The front layer machines perform their operations without breaking network communications between clients and servers, and without rebooting of computers.

System, method, and article of manufacture for wireless enablement of the world wide web using a wireless gateway

Abstract: A system, method and article of manufacture are provided for selection and formatting of web content for remote viewing. User-defined information is received and used to retrieve content from one or more web sites. The retrieved content is aggregated at a network server located remotely from the user. The aggregated content is formatted at the network server for display on a wireless device. The formatted content is transmitted to a wireless device for display on the wireless device.

Apparatus and method for virtual edge placement of web sites

Abstract: An apparatus and method for enhancing the infrastructure of a network such as the Internet is disclosed. Multiple edge servers and edge caches are provided at the edge of the network so as to cover and monitor all points of presence. The edge servers selectively intercept domain name translation requests generated by downstream clients, coupled to the monitored points of presence, to subscribing Web servers and provide translations which either enhance content delivery services or redirect the requesting client to the edge cache to make its content requests. Further, network traffic monitoring is provided in order to detect malicious or otherwise unauthorized data transmissions.

Electronic mail system with methodology providing distributed message store

Abstract: An electronic mail system with a methodology providing distributed message storage and processing is described. In particular, this methodology breaks up how the individual components of message data are stored. Message data itself is broken up into two parts: a metadata (mutable) portion, and an immutable portion. The metadata portion represents that part of the message data that may change over time. This includes message status flags (e.g., the IMAP “message deleted” flag) and the message's position within a particular message folder, among other information. The immutable portion, which comprises the bulk of electronic mail data (namely, the message itself), once stored is never edited. Immutable data is written f+1 times on as many unique servers, to tolerate f number of server failures using Lampson's stable storage algorithm. The metadata portion is stored 2f+1 times on as many unique servers to tolerate f number of server failures using quorum voting. Once the message has been stored once, instead of being copied, its location is passed around by reference. The system utilizes a two-tier architecture. One tier consists of servers which store message metadata and immutable data, the Data Servers, and servers that operating upon those data, the Access Servers. Message store integrity is maintained in the event of server failure and as the set of Data Servers changes. In the latter case, I/O and storage workloads are dynamically redistributed across Data Servers in an efficient way.