Ing. Josef Gattermayer, Ph.D.

Publications

Blockchain-Based Multi-Level Scoring System for P2P Clusters

Year
2017
Published
2017 46th International Conference on Parallel Processing Workshops (ICPPW). Piscataway (New Jersey): IEEE, 2017. p. 301-308. ISSN 1530-2016. ISBN 9781538610442.
Type
Proceedings paper
Annotation
Peer-to-peer (P2P) design offers many benefits over a single-master or a multi-master architecture in terms of scalability, reliability and independence. The Clondike project is being converted from a grid computing system into a universal non-dedicated P2P cluster where every participating node can benefit from its membership in the cluster. But different design requires different types of algorithms in order to guarantee the same functionality. One of the challenges in P2P design is a fair scheduling and a general protection of the whole cluster against abusive or malfunctioning nodes. Algorithms used in a single-master or multi-master clusters do not work anymore. We have designed a multi-level system based on one of the main principles of cryptocurrencies to achieve a distributed master-less reputation rating across the cluster. This paper discusses proposed cluster multi-level reputation system and its parameters. The system is evaluated on a Clondike cluster on an experimental measurement with abusive nodes involved.

Using Bootstraping Principles of Contemporary P2P File-Sharing Protocols in Large-Scale Grid Computing Systems

Year
2017
Published
2017 25th Euromicro International Conference on Parallel, Distributed and Network-based Processing (PDP). Piscataway: IEEE, 2017. p. 214-218. ISSN 1066-6192. ISBN 978-1-5090-6058-0.
Type
Proceedings paper
Annotation
As contemporary distributed systems reach their scalability limits, their architects search ways to push their boundaries further. One of the approaches is to convert a given distributed system into a peer-to-peer (P2P) structure. This approach causes more overhead compared to a single-master or multi-master architecture, but on larger scales (if properly designed) does not reach any boundaries. The Clondike project started as a grid computing system, but now it aims to create a universal non-dedicated P2P cluster where every participating node can benefit from its membership in the cluster. The P2P approach eliminates the single-point-of-failure problems and high availability is guaranteed by design. So far in the Clondike architecture, a bootstrap protocol was based on broadcasts, which became a limiting factor for the scalability of the whole cluster. We have compared existing P2P communication protocols used in a variety of P2P systems and contemporary P2P file-sharing protocols in order to find a suitable solution for Clondike. We have chosen Kademlia protocol and proven its logaritmic scalability in the Clondike environment. This paper presents results of our analysis and implementation and a series of measurement results comparing the old and new communication protocols.

Different Approaches to Distributed Compilation

Year
2012
Published
Parallel and Distributed Processing Symposium Workshops & PhD Forum (IPDPSW), 2012 IEEE 26th International. Los Alamitos, CA: IEEE Computer Soc., 2012. pp. 1128-1134. ISBN 978-1-4673-0974-5.
Type
Proceedings paper
Annotation
Source code compiling is a non-trivial task that requires many computing resources. As a software project grows, its build time increases and debugging on a single computer becomes more and more time consuming task. An obvious solution would be a dedicated cluster acting as a build farm, where developers can send their requests. But in most cases, this solution has a very low utilization of available computing resources which makes it very ineffective. Therefore, we have focused on non-dedicated clusters to perform distributed compilation, where we could use users' computers as nodes of a build farm. We compare two different approaches: distcc, which is an open-source program to distribute compilation of C/C++ code between several computers on a network and Clondike, which is a universal peer-to-peer cluster that is being developed at the Czech Technical University in Prague. A very complex task able to test deeply both systems is a compilation of a Linux Kernel with many config options. We have run this task on a cluster with up to 20 computers and have measured computing times and CPU loads. In this paper, we will present the results of this experiment that indicate the scalability and utilization of given resources in both systems. We also discuss the penalty of a generic solution over a task-specific one.

Porting Clondike to Heterogeneous Platforms

Year
2012
Published
2012 2nd IEEE International Conference On Parallel, Distributed and Grid Computing. Waknaghat: IEEE, 2012. p. 380-384. ISBN 978-1-4673-2922-4.
Type
Proceedings paper
Annotation
Clustering plays an important role in today's computer networks. We can achieve a higher efficiency of the whole network infrastructure by simply using idle computing power of ordinary workstations. The Clondike project aims to create a universal non-dedicated peer-to-peer cluster where every participating node can benefit from its membership in the cluster. The peer-to-peer approach does not contain any single point of failure, so a high availability is guaranteed by design. So far, we have tested Clondike only in our laboratory with homogeneous computer network architecture, all the computer nodes were the same. In this paper, we report on experiments with moving the Clondike cluster closer to a real environment: with porting Clondike to a real office network with heterogeneous computers. We have run a distributed compilation of the Linux Kernel on both platforms to verify our results and to assess the weaknesses of the current solution and to identify further development needs.

Cluster discovery in phase-shift beamformed ad-hoc and sensor networks

Year
2011
Published
Wireless Communications and Mobile Computing 2011. Piscataway: IEEE, 2011. pp. 1069-1074. ISBN 978-1-4244-9539-9.
Type
Proceedings paper
Annotation
The area of interfering radio waves has been studied thoroughly when the antennas are powered by the same radio chip (smart antennas, MIMO, antenna arrays, etc.), however the science of achieving good results in a distributed manner (one antenna per device) and over multiple layers in the communication stack (e. g. routing tables based on radio wave interference) is still in its infancy. The work of the authors is exactly to explore this realm of phase-shift interfering waves and this paper brings into attention the possibility of cluster discovery that will proceed communication between two clusters through phase-shift distributed beamforming.