DODAS: How to effectively exploit heterogeneous clouds for scientific computations

Dynamic On Demand Analysis Service (DODAS) is a Platform as a Service tool built combining several solutions and products developed by the INDIGO-DataCloud H2020 project. DODAS allows to instantiate on-demand container-based clusters. Both HTCondor batch system and platform for the Big Data analysis based on Spark, Hadoop etc, can be deployed on any cloud-based infrastructures with almost zero effort.  DODAS acts as cloud enabler designed for scientists seeking to easily exploit distributed and heterogeneous clouds to process data. Aiming to reduce the learning curve as well as the operational cost of managing community specific services running on distributed cloud, DODAS completely automates the process of provisioning, creating, managing and accessing a pool of heterogeneous computing and storage resources. DODAS was selected as one of the Thematic Services that will provide multi-disciplinary solutions in the EOSC-hub project, an integration and management system of the European Open Science Cloud starting in January 2018. The main goals of this contribution are to provide a comprehensive overview of the overall technical implementation of DODAS, as well as to illustrate two distinct real examples of usage: the integration within the CMS Workload Management System and the extension of the AMS computing model.