Eduardo Cunha de Almeida

João Eugenio Marynowski, Michel Albonico, Eduardo Cunha de Almeida et al.

MapReduce (MR) is the most popular solution to build applications for large-scale data processing. These applications are often deployed on large clusters of commodity machines, where failures happen constantly due to bugs, hardware problems, and outages. Testing MR-based systems is hard, since it is needed a great effort of test harness to execute distributed test cases upon failures. In this paper, we present a novel testing solution to tackle this issue called HadoopTest. This solution is based on a scalable harness approach, where distributed tester components are hung around each map and reduce worker (i.e., node). Testers are allowed to stimulate each worker to inject failures on them, monitor their behavior, and validate testing results. HadoopTest was used to test two applications bundled into Hadoop, the Apache open source MapReduce implementation. Our initial implementation demonstrates promising results, with HadoopTest coordinating test cases across distributed MapReduce workers, and finding bugs.

Rayson Laroca, Alessandra B. Araujo, Luiz A. Zanlorensi et al.

Existing approaches for image-based Automatic Meter Reading (AMR) have been evaluated on images captured in well-controlled scenarios. However, real-world meter reading presents unconstrained scenarios that are way more challenging due to dirt, various lighting conditions, scale variations, in-plane and out-of-plane rotations, among other factors. In this work, we present an end-to-end approach for AMR focusing on unconstrained scenarios. Our main contribution is the insertion of a new stage in the AMR pipeline, called corner detection and counter classification, which enables the counter region to be rectified -- as well as the rejection of illegible/faulty meters -- prior to the recognition stage. We also introduce a publicly available dataset, called Copel-AMR, that contains 12,500 meter images acquired in the field by the service company's employees themselves, including 2,500 images of faulty meters or cases where the reading is illegible due to occlusions. Experimental evaluation demonstrates that the proposed system, which has three networks operating in a cascaded mode, outperforms all baselines in terms of recognition rate while still being quite efficient. Moreover, as very few reading errors are tolerated in real-world applications, we show that our AMR system achieves impressive recognition rates (i.e., > 99%) when rejecting readings made with lower confidence values.