Section: Overall Objectives

Challenges

To our opinion the algorithmic challenges of such systems are located at the application and service layers. In addition to these two types of challenges, we identify a third one which consists in the evaluation of models, algorithms and implementations. To summarize, the three research areas that we address are:

applications:

We have to organize the application and its access to the middleware in a way that is convenient for both. The application should restrict itself to a sensible usage of the middleware and make the least assumptions about the other underlying (and hidden) layers.

services:

The service layer has to organize the infrastructure in a convenient way such that resources are used efficiently and such that the applications show a good performance.

performance (and correctness) evaluation:

To assert the quality of computational models and algorithms that we develop within such a paradigm, we have to compare algorithms and program executions amongst each other. A lot of challenges remain in the reproducibility of experiments and in the extrapolation to new scales in the number of processors or the input data size. Traditionally, the application performance was the main concern in our domain while application correctness was seen as a simpler issue, to be solved through testing. This is not true anymore because of the scale reached by modern applications, mandating formal assessment methods of the application correction.