Javier Alonso

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In this paper, we present an approach for software rejuvenation based on automated self-healing techniques that can be easily applied to off-the-shelf Application Servers and Internet sites. Software aging and transient failures are detected through continuous monitoring of system data and performability metrics of the application server. If some anomalous(More)
This paper presents our approach to TORCS Car Racing Competition 2009, it is based on a complete modular architecture capable of driving automatically a car along a track with or without oppents. The architecture is composed of five simple modules being each one responsible for a basic aspect of car driving. The modules control gear shiftings, steer(More)
The growing complexity of software systems is resulting in an increasing number of software faults. According to the literature, software faults are becoming one of the main sources of unplanned system outages, and have an important impact on company benefits and image. For this reason, a lot of techniques (such as clustering, fail-over techniques, or(More)
Grid applications comprise several components and web-services that make them highly prone to the occurrence of transient software failures and aging problems. This type of failures often incur in undesired performance levels and unexpected partial crashes. In this paper we present a technique that offers high-availability for Grid services based on(More)
Artificial intelligence techniques applied to control processes are particularly useful when the elements to be controlled are complex and can not be described by a linear model. A trade-off between performance and complexity is the main factor in the design of this kind of system. The use of fuzzy logic is specially indicated when trying to emulate such(More)
Traditionally, performance has been the most important metrics when evaluating a system. However, in the last decades industry and academia have been paying increasing attention to another metric to evaluate servers: availability. A web server may serve many users when running, but if it is out of service too much time, it becomes useless and expensive. The(More)
Faults in software systems can have different characteristics. In an earlier paper, the anomaly reports for a number of JPL/NASA missions were analyzed and the underlying faults were classified as Bohrbugs, non-aging-related Mandelbugs, and aging-related bugs. In another paper the times to failure for each of these fault types were examined to identify(More)
Light Detection and Ranging (LIDAR) sensors are commonly used in perception for autonomous vehicles because of their high accuracy, speed, and range. These characteristics make the sensor suitable for integration into the perception layer of controllers which have the capacity to avoid collisions with unpredicted obstacles. The objective of this work was to(More)
Students of Computer Science freshman year usually develop assembler programs to learn processor architecture. Homework exercises are done on paper, while those in lab sessions are solved with the aid of programming tools. Students perceive theory and lab as different subjects, so they don’t use lab tools to test their theory solved problems. Moreover,(More)