My HPC-Europa visit to EPCC

Author: Guest blogger
Posted: 20 Nov 2018 | 09:08

 

Pablo C. Cañizares came on an HPC-Europa3 visit to EPCC from 23 July–24 October 2018. In this blog article he summarises his visit.

Hi there! I'm Pablo C. Cañizares, a PhD student in Computer Science from the Complutense University of Madrid (UCM), Spain. I work in the Design and Testing of Reliable Systems group in the Computer Science Faculty of the UCM. I visited EPCC for three months under the HPC-Europa3 transnational access programme and was hosted by EPCC's Dr David Henty.

My research areas are related to the modelling and testing of cloud computing and HPC environments. This includes topics such as formal modelling of cloud systems, performance evaluation of highly distributed systems, and testing distributed systems and applications. I have contributed advances in the area of mutation-testing techniques, which focus on the analysis of the suitability of test suites provided by the applications themselves (that is, you mutate the original source code, eg change a `+` to `-`, to see whether the test suite can pick up such changes). This is a computationally expensive process as, although you only make a very small change per mutation, you can eventually produce a large number of codes, each with a different mutation, to test the test suite. These tests need to be performed (that is, need to be run) in highly distributed systems. The result is a quality check on the test suite provided by the application.

During my visit, I worked on optimising a mutation-testing process on distributed systems. Although our previous work had efficiently exploited the computational resources provided through distributed systems, several bottlenecks had been detected while applying these strategies to large-scale systems. For this reason, the proposal was three-fold:

  • Providing a hybrid algorithm designed to reduce the communications between a master and worker processes model while maintaining a high level of resources usage
  • Improving the compilation phase of mutated code
  • Comparing the proposed system with other distribution solutions, such as using Spark or Cloud systems.

The results of the experiments are promising, showing that the proposal reduces the execution cost by exploiting parallelism and provides a better speed-up than other existing approaches. 

In addition to the 'hardworking' time, I really enjoyed the city of Edinburgh and its marvellous landscapes during my running sessions. I feel very lucky since I was able to enjoy the Fringe festival, that is an excellent experience. Also I fell in love with the Highlands, the history of this country, and the friendliness of its people. In summary, I strongly recommend the HPC-Europa experience, particularly in EPCC. Working with Dr David Henty, collaborating with Dr Rosa Filgueira (an HPC-Europa visitor under a previous programme and now working at EPCC), and relying on the support that Dr Mario Antonioletti provided has been a really great experience.