Web Requests Research Articles

P2PRPIPS: A P2P and Reverse Proxy Based Web Intrusion Protection System

In order to protect web sites with various program languages and high throughput efficiently, a web Intrusion Protection System (IPS) based on P2P and reverse proxy architecture was designed and implemented. The P2P based web intrusion protection system has multi web firewall nodes and nodes with same program cooperate with each other under P2P architecture. Some nodes work as net flow allocator and some work as detector and they can convert to each other according to the requirements dynamically. The WAF program has the characteristics of session keeping and load balancing and it can detect messages by using expert library and many plug-in components. The technology of reverse proxy is used for response the web request. Experiments show that the system can effectively prevent attacks form application layer. It is proved more efficient and stable than single node.

EPLogCleaner: Improving Data Quality of Enterprise Proxy Logs for Efficient Web Usage Mining

Data cleaning is an important step performed in the preprocessing stage of web usage mining, and is widely used in many data mining systems. Despite many efforts on data cleaning for web server logs, it is still an open question for enterprise proxy logs. With unlimited accesses to websites, enterprise proxy logs trace web requests from multiple clients to multiple web servers,which make them quite different from web sever logs on both location and content. Therefore, many irrelevant items such as software updating requests cannot be filtered out by traditional data cleaning methods. In this paper, we propose the first method named EPLogCleaner that can filter out plenty of irrelevant items based on the common prefix of their URLs. We make an evaluation of EPLogCleaner with a real network traffic trace captured from one enterprise proxy. Experimental results show that EPLogCleaner can improve data quality of enterprise proxy logs by further filtering out more than 30% URL requests comparing with traditional data cleaning methods.

DoubleGuard: Detecting Intrusions in Multitier Web Applications

Internet services and applications have become an inextricable part of daily life, enabling communication and the management of personal information from anywhere. To accommodate this increase in application and data complexity, web services have moved to a multitiered design wherein the webserver runs the application front-end logic and data are outsourced to a database or file server. In this paper, we present DoubleGuard, an IDS system that models the network behavior of user sessions across both the front-end webserver and the back-end database. By monitoring both web and subsequent database requests, we are able to ferret out attacks that an independent IDS would not be able to identify. Furthermore, we quantify the limitations of any multitier IDS in terms of training sessions and functionality coverage. We implemented DoubleGuard using an Apache webserver with MySQL and lightweight virtualization. We then collected and processed real-world traffic over a 15-day period of system deployment in both dynamic and static web applications. Finally, using DoubleGuard, we were able to expose a wide range of attacks with 100 percent accuracy while maintaining 0 percent false positives for static web services and 0.6 percent false positives for dynamic web services.

Cooperative Cashing? An Economic Analysis of Document Duplication in Cooperative Web Caching

Cooperative caching is a popular mechanism to allow an array of distributed caches to cooperate and serve each others' Web requests. Controlling duplication of documents across cooperating caches is a challenging problem faced by cache managers. In this paper, we study the economics of document duplication in strategic and nonstrategic settings. We have three primary findings. First, we find that the optimum level of duplication at a cache is nondecreasing in intercache latency, cache size, and extent of request locality. Second, in situations in which cache peering spans organizations, we find that the interaction between caches is a game of strategic substitutes wherein a cache employs lesser resources towards eliminating duplicate documents when the other caches employs more resources towards eliminating duplicate documents at that cache. Thus, a significant challenge will be to simultaneously induce multiple caches to contribute more resources towards reducing duplicate documents in the system. Finally, centralized decision making, which as expected provides improvements in average latency over a decentralized setup, can entail highly asymmetric duplication levels at the caches. This in turn can benefit one set of users at the expense of the other, and thus will be challenging to implement.

Anomaly-based Techniques for Web Attacks Detection

The widespread use of the Internet comes accompanied with severe threats for web applications security. Intrusion Detection Systems (IDS) have been considered to deal with the diversity and complexity of web attacks. In this context, this work proposes an algorithm for web attack detection, exploring ananomaly-based technique: the wavelet transform. The proposed algorithm analyzes anomalies within variations on characters frequencies in web requests. Experimental results show high rates of detection without false positive occurrences.Keywords: Web Attacks, Anomaly Detection, Wavelet Transform, Web Applications.

Effective and Efficient Multi-Facet Web Image Annotation

The vast amount of images available on the Web request for an effective and efficient search service to help users find relevant images. The prevalent way is to provide a keyword interface for users to submit queries. However, the amount of images without any tags or annotations are beyond the reach of manual efforts. To overcome this, automatic image annotation techniques emerge, which are generally a process of selecting a suitable set of tags for a given image without user intervention. However, there are three main challenges with respect to Web-scale image annotation: scalability, noise-resistance and diversity. Scalability has a twofold meaning: first an automatic image annotation system should be scalable with respect to billions of images on the Web; second it should be able to automatically identify several relevant tags among a huge tag set for a given image within seconds or even faster. Noise-resistance means that the system should be robust enough against typos and ambiguous terms used in tags. Diversity represents that image content may include both scenes and objects, which are further described by multiple different image features constituting different facets in annotation. In this paper, we propose a unified framework to tackle the above three challenges for automatic Web image annotation. It mainly involves two components: tag candidate retrieval and multi-facet annotation. In the former content-based indexing and concept-based codebook are leveraged to solve scalability and noise-resistance issues. In the latter the joint feature map has been designed to describe different facets of tags in annotations and the relations between these facets. Tag graph is adopted to represent tags in the entire annotation and the structured learning technique is employed to construct a learning model on top of the tag graph based on the generated joint feature map. Millions of images from Flickr are used in our evaluation. Experimental results show that we have achieved 33% performance improvements compared with those single facet approaches in terms of three metrics: precision, recall and F1 score.

SearchCal: a Virtual Observatory tool for searching calibrators in optical long-baseline interferometry

Context. In long-baseline interferometry, images or astrophysical parameters are obtained from the raw fringe contrast after a careful calibration process. We have already developed the software (SearchCal) to select suitable bright calibration stars (V ≤ 10; K ≤ 5.0) for obtaining the ultimate precision of current interferometric instruments like the VLTI. With the expected gain in sensitivity of AMBER and PRIMA on the VLTI, the need for fainter calibrators should now be adressed. Aims. We present a new version of SearchCal dedicated to the creation of an evolving catalog of stars suitable as calibrators with K magnitude >5 around the scientific target. Methods. Star catalogs available at the CDS are searched via web requests and provide the useful astrometric and photometric informations for selecting calibrators. The missing photometries are computed with an accuracy of about 0.1 mag. The stellar angular diameter is estimated with a precision of about 10% through newly determined surface-brightness versus color-index relations based on the I, J, H and K magnitudes. For each star the squared visibility is computed taking into account the central wavelength and the maximum baseline of the predicted observations. Results. The version of SearchCal for faint objects that allows to find calibrators for interferometric observations up to K ∼ 15 is available as a web service at the address: http://www.jmmc.fr/searchcal

How to Evaluate the Financial Health of a Retirement Home

When you evaluate a retirement home a loved one, you are likely to consider the standard of care delivered, the attractiveness of the facility, how friendly the staff is, how convenient the home is to where you live, and other qualitative characteristics. You should also consider the financial sustainability of the home. You want to avoid homes that are stretched financially to avoid the deteriorating care that would likely follow. Further, you want to avoid having to move your loved one again in the future. Demand retirement homes has fallen because of the economic weakness of 2008-2009. This weakens their financial condition and should heighten the concern of potential new residents. Here are methods of gathering information to assess the continuing viability of a home. HOMES IN GENERAL Generally, retirement homes are overseen by state agencies. Ask the home what agency oversees them. Go to the agency's Web site and see what information you can find. Agencies generally grade the homes. Take a look at the Web site known as http://www.carepathways .com ratings on homes. Ask the home to show you their last written review. Is the home accredited? Some homes choose to get accredited by the Continuing Care Accreditation Commission (CCAC). Nationally, only about 15% of retirement homes are accredited. Staff turnover in management is a good indicator of a stable business. How long has the management been there? What is the occupancy rate? Ask what their break-even occupancy is. Ask how they came through the 2008-2009 period. If they tell you everything is wonderful, I would doubt it. Break-even occupancy is probably in the range of 88%-90% occupancy. One or two percentage points of profitability produce a big dollar difference to the owner. Why does this matter? If it is a for profit and the owners are consistently losing money, they will either look to sell or reduce services to cure their losses. How much have the monthly charges or service fees risen each year? Ask if there is any reason why this increase would change in the future. Is the building going to require extraordinary maintenance? Is there a lot of local competition? Where does this retirement home fit in relative to others locally? Is it the most expensive? If the local economy is weak, the most expensive may be likely to lose residents to less expensive homes. Are there any new retirement homes under construction in the local area? If so, do they plan to have services or facilities that are more compelling? Is there a waiting list? This indicates demand the facility. Is the surrounding environment losing population? Have major businesses closed their facilities? The local chamber of commerce can give you population statistics. Retirement homes are either publicly owned or privately owned. If the home is publicly owned, you will have access to lots of information about the financial condition. When a home is privately owned, the amount of hard data about their financial condition may be limited. You can use your intuition to gather a mosaic of the financial strength of the home. Publicly Owned Two of the best known publicly owned home companies are Sunrise Senior Living and Assisted Living Concepts. To evaluate a publicly owned home, start with Yahoo! Finance and enter the name of the company. Start with the basic profile on the Web site. Read the data presented there. Look at the number of homes they own and the geographic locations. The most important piece of information is the operating cash flow. You can find this number on the bottom of the left hand column on the Yahoo! Finance Key Statistics page. You want a home that is profitable to its owners. You can also look at the stock chart a 5-year period. This will give you an idea of how well regarded the company is as a going concern. Go on the company Web site and request a copy of the annual report and 10-K report. …

Faking It

CPUs are no longer getting faster. Instead, CPU manufacturers now package multiple cores in each CPU and ask us developers to put them to good use. Writing parallel code using multiple threads or even a higher-level API is a fiendishly difficult task. An alternative approach involves using a programming language that can easily exploit multiple cores, but it requires substantial effort. A third way involves faking your application's multicore-handling dexterity by handing over this responsibility. At the highest level, it's easy to put multiple cores to work if your application serves Web requests (pass them to a Web application server) or dishes out SQL statements (via a commercial RDBMS). Another high-level way to utilize multiple cores is to let the operating system do it for you by splitting your processing among independent processes. You can do this by using pipelines of communicating processes, by splitting the work among many instances of the same process with GNU parallel, or by parallelizing independent work items with make -j. At the application level, you can do the same by employing the map-reduce and filter-reduce techniques.

Surveying the General Public over the Internet Using Address-Based Sampling and Mail Contact Procedures

We report results from two statewide experiments in Washington designed to test potential methods for using postal mail to obtain survey responses over the Internet from address-based samples of general public households. The five methods we test are: 1) sending Web and mail modes of response sequentially; 2) providing a prepaid $5 incentive; 3) offering an instruction card for responding over the Web; 4) sending the follow-up request by Priority Mail; and 5) providing an additional $5 incentive with this follow-up request. Results are evaluated from the standpoint of response rates, demographic representativeness of respondents, and survey costs and data collection times for Web and mail modes. We find that a “Web-plus-mail” design—mailing an initial Web request followed by a mail request—with the prepaid incentive offers much potential for obtaining Internet responses. In addition, the mail follow-up to the initial Web request significantly increases overall response rates and improves respondent representativeness. However, the results also show that a mail-only design consistently obtains higher response rates and a demographically similar sample compared to Web-plus-mail. We also find significant challenges in obtaining a representative sample of respondents with either Web or mail modes and in realizing the potential cost and speed benefits of the Internet in using postal mail contacts.

The Research and Design of Two-Level Load Balancer Based on Web Server Cluster

At present, the extendible Web server clusters are the important framers for the high performance network servers. The architecture based on load balancer is often used on web server clusters. The load balancer is the main bottleneck in improving performance of cluster. For it is hard to complete the task of assigning the requests from the client while collecting the real load information of the web servers efficiently. In this paper, we propose a model of two levels load balancer for web cluster to resolve the contradiction. When web requests are arrive, the first-level balancer continuously assigned them by to the second-level which consist of some load balancers connect to real web servers and receive real-time load information of them. Round robin algorithm is used at the first-level load balancer to schedule the client’s requests in order to shorten the response time. The proposed algorithm in our model is run at the second-level load balancers to schedule the requests to real web servers according to the real load information. At last, a simple test is carried out to make sure the performance of the model. The result of the test shows that the model has made better load balancing.

SOA distributed operating system for managing embedded devices in home and building automation

Wireless sensor networks have become an essential part of home and building automation, especially for energy management and health monitoring. This paper presents a Distributed Operating System (DOS) based on the Service-Oriented Architecture (SOA) to manage all embedded devices in a home network at high level of interoperability. This system can solve many problems related to accessing home network from Internet and future networks like Smart Grids. The proposed system takes into consideration the limited resources of sensors as well as the matters of simultaneous multi-access, eventing, authorization, security and scheduling the on-line time of sensors in order to reduce power consumption. The paper shows the advantages of using some features of our SOA distributed operating system, like using a queue with a dispatcher to dispatch the simultaneous web requests and also using cache and scheduling, in addition to using a requester to enable accessing embedded devices with different networking protocols. These features help in increasing the quality of services and reaching high level of reliability.

Configuration Management in Multi-Channel Multi-Container Web Application Servers

The Multi-Container Web server allows the division of a single web request into independent portions to be executed in parallel over different communication channels. To achieve this, the underlying communication infrastructure of traditional web environments is changed from the state-full TCP to the stateless UDP communication protocol. Such an architectural change provided an environment suitable for parallelization and distribution and enhanced some other already existing characteristics of the current web environments such as fault tolerance and web caching. In this paper, performance is further enhanced as part of the framework upon which web applications will run by introducing a number of changes. The configuration Manager (CM) is the subsystem that is responsible for reading configuration files provided by administrator. The CM is split into two parts, which are the Container CM and the HPA CM. After the CM reads the necessary configuration files and validates its content, it makes it easy for the administrators to be able to change environment setting such as container port ranges, types of nodes, services names, services location, number of instances each service should be loaded, and more. The CM also have the capability to reconstruct some types of configuration files from its data structure buffers, as such buffers may change through other subsystems and such changes may need to be permanent.

A neural network proxy cache replacement strategy and its implementation in the Squid proxy server

As the Internet has become a more central aspect for information technology, so have concerns with supplying enough bandwidth and serving web requests to end users in an appropriate time frame. Web caching was introduced in the 1990s to help decrease network traffic, lessen user perceived lag, and reduce loads on origin servers by storing copies of web objects on servers closer to end users as opposed to forwarding all requests to the origin servers. Since web caches have limited space, web caches must effectively decide which objects are worth caching or replacing for other objects. This problem is known as cache replacement. We used neural networks to solve this problem and proposed the Neural Network Proxy Cache Replacement (NNPCR) method. The goal of this research is to implement NNPCR in a real environment like Squid proxy server. In order to do so, we propose an improved strategy of NNPCR referred to as NNPCR-2. We show how the improved model can be trained with up to twelve times more data and gain a 5–10% increase in Correct Classification Ratio (CCR) than NNPCR. We implemented NNPCR-2 in Squid proxy server and compared it with four other cache replacement strategies. In this paper, we use 84 times more data than NNPCR was tested against and present exhaustive test results for NNPCR-2 with different trace files and neural network structures. Our results demonstrate that NNPCR-2 made important, balanced decisions in relation to the hit rate and byte hit rate; the two performance metrics most commonly used to measure the performance of web proxy caches.

A Model for Reducing Power Consumption in Peer-to-Peer Systems

Information systems based on the cloud computing model and peer-to-peer (P2P) model are now getting popular. In the cloud computing model, a cloud of servers support thin clients with various types of service like Web pages and databases. On the other hand, every computer is peer and there is no centralized coordinator in the P2P model. It is getting more significant to discuss how to reduce the total electric power consumption of computers in information systems to realize eco-society. In this paper, we consider a Web type of application on P2P overlay networks. First, we discuss a model for showing how much each server peer consumes electric power to perform Web requests from client peers. Then, we discuss algorithms for a client peer to select a server peer in a collection of server peers so that the total power consumption can be reduced while some constraint like deadline one is satisfied. Lastly, we evaluate the algorithms in terms of the total power consumption and throughput compared with traditional round robin algorithms.

Feedback Load Control Mechanism for Real-Time Web Services

This paper proposes a mechanism for managing overload in real-time web service system. The many previous mechanisms manage overload with controlling web request. These mechanisms can control only new web request. They don't have any control existing tasks, especially periodic tasks. We design a controller that able to meet real-time performance with controlling even periodic tasks. A feedback control system is implemented applying the proposed mechanism. And we verified the stable operation of system.

Reducing errors in the anomaly-based detection of web-based attacks through the combined analysis of web requests and SQL queries

Web-based applications have become a popular means of exposing functionality to large numbers of users by leveraging the services provided by web servers and databases. The wide proliferation of custom-developed web-based applications suggests that anomaly detection could be a suitable approach for providing early warning and real-time blocking of application-level exploits. Therefore, a number of research prototypes and commercial products that learn the normal usage patterns of web applications have been developed. Anomaly detection techniques, however, are prone to both false positives and false negatives. As a result, if anomalous web requests are simply blocked, it is likely that some legitimate requests would be denied, resulting in decreased availability. On the other hand, if malicious requests are allowed to access a web application's data stored in a back-end database, security-critical information could be leaked to an attacker. To ameliorate this situation, we propose a system composed of a web-based anomaly detection system, a reverse HTTP proxy, and a database anomaly detection system. Serially composing a web-based anomaly detector and a SQL query anomaly detector increases the detection rate of our system. To address a potential increase in the false positive rate, we leverage an anomaly-driven reverse HTTP proxy to serve anomalous-but-benign requests that do not require access to sensitive information. We developed a prototype of our approach and evaluated its applicability with respect to several existing web-based applications, showing that our approach is both feasible and effective in reducing both false positives and false negatives.

Guest Editors' Introduction: The Many Faces of Semantics

The Semantic Web enables programs and agents to automatically understand what data is about, and therefore bridge the so-called semantic gap between the ways in which users request Web resources and the real needs of those users, ultimately improving the quality of Web information retrieval. This issue presents four expanded articles from The First International Workshop on the Many Faces of Multimedia Semantics.

New guidelines on the use of iodinated contrast media: a report on an implementation project

The aim of this paper is to report on the implementation of new guidelines on the use of injectable iodinated contrast media (ICM) at our workplace and specific protocols for the preparation of patients at risk. Operators received training with continuing medical education (CME) credits. The new documentation (patient history/screening form and informed consent form) is available on the hospital Web site and requests serum creatinine determination with estimation of glomerular filtration rate (GFR) for every patient. Additional tests are required for high-risk patients only. Attendance rates were 57.2% among referring physicians and 74.5% among Radiology Department personnel. The Cockcroft-Gault formula was used to estimate GFR in adults. The main problem encountered in the implementation process was that referring physicians failed to evaluate the GFR in 80% of patients, with low GFR being discovered in the Radiology Department on the day of examination in 20% of patients, resulting in a need to reschedule the examination. Although not an easy task, implementation of the new guidelines for ICM use is both feasible and necessary. An additional refresher training course for personnel and GFR evaluation of the patient on referral are indispensable to ensure proper preparation of patients at increased risk of adverse reactions to ICM.

Cooperative Caching?: An Economic Analysis of Document Duplication in Cooperative Web Caching

Cooperative caching is a popular mechanism to allow an array of distributed caches to cooperate and serve each others' web requests. Monitoring and controlling duplication of documents across cooperating caches is a challenging operational problem faced by cache managers. In this paper, we analyze optimal duplication in a game-theoretic setting with two cooperating caches. We have three primary findings. First, our results suggest that intermediate levels of duplication - greater than that of CARP, a protocol that allows no duplication, but less than that of ICP, a protocol that does not monitor duplication - are desirable. Second, the game is a game of strategic substitutes wherein an increase in duplication by one cache results in a decrease in duplication by the other. Thus, a cache that can credibly signal that it is incapable of monitoring duplication levels can get higher contribution from other caches i.e., get other caches to eliminate more duplicate documents. Finally, decentralized decision-making by selfish caches can be quite inefficient (i.e., result in higher average latency) relative to the socially optimal solution. At the same time, the socially optimal solution can be highly asymmetric even when caches are symmetric and thus may not be acceptable to the cache that has to contribute the most resources. These factors should be accounted for when contracts for cooperative caching are structured by independent ISPs.