The paper presents the result of an evaluation of the performance of different message broker system configurations, which lead to the construction of the specific architecture guidelines for such systems. The examples are provided for an exemplary middleware messaging server software - RabbitMQ, set in high availability - enabling and redundant configurations. Rabbit MQ is a message queuing system realizing the middleware for distributed systems that implements the Advanced Message Queuing Protocol. The scalability and high availability design issues are discussed and the possible cluster topologies and their impact is presented. Since HA and performance scalability requirements are in conflict, scenarios for using clustered RabbitMQ nodes and mirrored queues are interesting and have to be considered with specific workloads and requirements in mind. The results of performance measurements for some topologies are also reported in this article.

In this article, authors analyze methods of the analysis of data integrity, security and availability loss results for business processes. Assessing those results, one can judge the importance of a process in organization; thus, determine which business process requires more attention. The importance of those processes can be determined with Business Impact Analysis (BIA). In article, first phase of BIA is presented – in specific, a construction of Business Impact Category Tables, Loss Levels and process weight calculation methods. A variety of weight calculating methods is presented. Authors also present their proposed method – square sum percentage – as a solution eliminating problems of other weight calculation methods in business impact analysis.

Extensive use of computer networks is associated with the development of various effective methods that are suitable for hiding information in the contents transferred over the network. These methods are described as network steganography. Since web applications use HTTP protocol to transmit the requests to the server and send the answers to the final recipient, specifically HTTP protocol is ideal for hiding information. For example, there are several methods that can be used to transmit the additional content in the HTTP header. In this paper, we present authors’ evaluation method for network steganography using HTTP specific properties and evaluate the effectiveness of some techniques, providing experimental results.

This article gives an introduction to NoSQL movement and how it can help in creating modem application trends of Web 2.0 by its scalability and performance. To achieve the objectives of this work, three types of databases have been tested to see which of them will be the best to work with mobile devices working on Android system. All received results were presented and commented.