Support for Provisioning and Configuration Decisions for Data Intensive Workflows

System provisioning, resource allocation, and configuration decisions for I/O-intensive workflow applications are complex even for expert users. Users face choices at multiple levels: allocating resources to individual sub-systems (e.g., the application layer, the storage layer) as well as configuring each of these optimally (e.g., replication level, chunk size, caching policies in case of storage) all having a large impact on the overall application performance. This paper presents a solution to address the problem of supporting these provisioning, allocation and configuration decisions for workflow applications. To enable selecting a good choice in a reasonable time, we propose an approach that accelerates the exploration of the configuration space based on a low-cost performance predictor that estimates total execution time of a workflow application in a given setup. We evaluate the predictor in a number of different scenarios including the Montage application: a workflow composed of over 7,500 tasks structured in 10 different stages with varying characteristics. Our evaluation shows that: (i) the predictor is effective in identifying the desired system configuration, (ii) it can scale to model a complex workflow application run on a 100-node cluster, while (iii) using orders of magnitude less resources than running the actual application. Additionally, we extend the predictor to estimate the energy usage of the system, and we present our experience with incorporating it in the development process of a distributed storage system.