Michael Smit

Mitigating DoS Attacks Using Performance Model-Driven Adaptive Algorithms

Denial of Service (DoS) attacks overwhelm online services, preventing legitimate users from accessing a service, often with impact on revenue or consumer trust. Approaches exist to filter network-level attacks, but application-level attacks are harder to detect at the firewall. Filtering at this level can be computationally expensive and difficult to scale, while still producing false positives that block legitimate users.n This article presents a model-based adaptive architecture and algorithm for detecting DoS attacks at the web application level and mitigating them. Using a performance model to predict the impact of arriving requests, a decision engine adaptively generates rules for filtering traffic and sending suspicious traffic for further review, where the end user is given the opportunity to demonstrate they are a legitimate user. If no legitimate user responds to the challenge, the request is dropped. Experiments performed on a scalable implementation demonstrate effective mitigation of attacks launched using a real-world DoS attack tool.

A runtime cloud efficiency software quality metric

This paper introduces the Cloud Efficiency (CE) metric, a novel runtime metric which assesses how effectively an application uses software-defined infrastructure. The CE metric is computed as the ratio of two functions: i) a benefit function which captures the current set of benefits derived from the application, and ii) a cost function which describes the current charges incurred by the applications resources. We motivate the need for the CE metric, describe in further detail how to compute it, and present experimental results demonstrating its calculation.

Toward understanding how users respond to rumours in social media

As the spread of rumours has been increasing every day in online social networks (OSNs), it is important to analyze and understand this phenomenon. Damage caused by the spread of rumours is difficult to handle without a full understanding of the dynamics behind it. One of the central steps of understanding rumour spread is to analyze who spread rumours online, why, and how. In this research, we focus on the steps who and why by describing, implementing, and evaluating an approach that studies whether or not a group of users is actively involved in rumour discussions, and assesses rumour-spreading personality types in OSNs. We implement this general approach using Reddit data, and demonstrate its use by determining which users engage with a recurring rumour, and analyzing their comments using qualitative methods. We find that we can reliably classify users into one of three categories: (1) “Generally support a false rumour”, (2) “Generally refute a false rumour”, or (3) “Generally joke about a false rumour”. Combining text mining techniques, such as text classification, sentiment analysis, and social network analysis, we aim to identify and classify those rumour-spreading user categories automatically and provide a more holistic view of rumour spread in OSNs.

Canadian public libraries and search engines: barriers to visibility

The purpose of this paper is to examine the challenges presented by search engine visibility for public libraries. The paper outlines the results of a pilot study investigating search engine visibility in two Canadian public libraries.,The study consists of semi-structured interviews with librarians from two multi-branch Canadian public library systems, combined with quantitative data provided by each library, as well as data obtained through site-specific searches in Google and Bing. Possible barriers to visibility are identified through thematic analysis of the interviews.,The initial findings of this pilot study identify a complex combination of barriers to visibility on search engines, in the form of attitudes, policies, organizational structures, and technological difficulties.,This paper describes a small, preliminary pilot study. More research is needed before any firm conclusions can be reached.,A review of the literature shows the increasing importance of search engine visibility for public libraries. By delving into the underlying issues which may be affecting libraries’ progress on the issue, this paper may help inform libraries’ decision-making processes and practices.,There has been little original research investigating the reasons behind libraries’ lack of visibility in search engine results pages. This paper provides insight into a previously unexplored area by exploring public libraries’ relationships with search engines.

Being where the people are: the challenges and benefits of search engine visibility for public libraries

Purpose – The purpose of this paper is to examine the challenges and benefits presented by search engine visibility for public libraries. This paper outlines the preliminary results of a pilot study investigating search engine visibility in two Canadian public libraries, and discusses practical approaches to search engine visibility. Design/methodology/approach – The study consists of semi-structured interviews with librarians from two multi-branch Canadian public library systems, combined with quantitative data provided by each library, as well as data obtained through site-specific searches in Google and Bing. Possible barriers to visibility are identified through thematic analysis of the interviews. Practical approaches are identified by the author based on a literature review. Findings – The initial findings of this pilot study identify a complex combination of barriers to visibility on search engines, in the form of attitudes, policies, organizational structures and technological difficulties. Resear...

Supporting software evolution to the multi-cloud with a cross-cloud platform

The evolution of software to best exploit the capabilities and advantages of cloud computing is attracting growing academic and industrial interest. The potential advantages - flexibility, scalability, pay-as-you-go - to software deployment are enhanced by multi-cloud deployments (e.g., public-private hybrid clouds). However, this evolution requires specialized knowledge at the systems level, some level of autonomous self-management, and specialized knowledge about the behavior of various cloud systems. In this talk, I introduce a platform that enables developers to deploy and manage applications on cloud systems with a significantly reduced requirement for specialized knowledge. The platform offers an abstracted view of deployed resources, and abstract actions to execute changes on those resources, allowing the author of an autonomic system to focus on analyzing the environment and making sound planning decisions. This allows developers with limited systems knowledge to write self-managing algorithms for their applications. I describe a proof-of-concept implementation, demonstrate its use in a cloud bursting scenario, and present early evidence of scalability.

Converged Reality: A Data Management Research Agenda for a Service-, Cloud-, and Data-Driven Era

We are accustomed to distinguishing activities that occur on or through the Internet as distinct from activities that occur in the physical world: online versus offline, virtual reality versus reality, and so on. As Internet-based services have evolved, this distinction has continued to blur. We now have a converged reality: the online does not merely augment the offline, rather, the two are increasingly indistinguishable. Mobility, cloud computing, service-driven technology, cognitive computing, and Big Data analytics are some of the distinct but related innovations driving this shift. Because the shift is happening in pieces across multiple areas and sectors, our converged reality is emergent and grassroots, not a carefully planned joint effort. There are therefore areas that have been and will be slow to acknowledge and adapt to this shift, data management is one of these areas. This paper describes how this converged reality grew from previous research into bridging online and offline worlds, and how it will lead to a cognitive reality. It identifies enablers and dampeners, and describes a data management research agenda specifically for converged reality. The proposed research agenda is intended to spark discussion and engage further work in this area.

Second International Workshop on Personalized Web Tasking - Summary

The objective of the Personalized Web Tasking (PWT) workshop series is to develop a community interested in the overlap between web services (as interoperable and easily composable components) and configurable personalizable applications. On the one hand, the core web-service community focuses primarily on enabling/supporting the processes around building distributed systems using services as the basic building blocks. On the other hand, user-centric communities have long been interested in enabling end users to customize their own experience using web resources, context-aware computing, and adaptive software, among others. PWT 2014, held during the IEEE World Congress on Services, focused on the overlap between the two areas, and brought together international researchers examining research relevant to this overlap.