# Atenea Exams, an IMS LTI Application to Solve Scalability Problems: A Study Case
## 1 Introduction
At the second MoodleMoot Espana conference organized in the Canary Islands in 2005, the case of the adoption of Moodle by the UPC was presented. The case of Atenea as an instance of Moodle for more than 30,000 users was a success story that validated the viability of Moodle at the technological level, as a teaching and organizational tool, and contributed to other Spanish universities and education departments adopted Moodle as an LMS to support their university, primary and secondary education. The UPC has been active in its collaboration within the Moodle community, doing research, providing services, proposing improvements and adding developments to the codebase. Until 2020 the Atenea platform has been operating without problems serving the university community. In 2010, UPCnet started changing its internal server architectures in its Data Processing Center (DPC). After an initial phase of virtualization of the physical servers, the DPC started to operate a private cloud. A private cloud is a model of hosting where cloud computing services and IT infrastructure are hosted privately and dedicated to a single organization with isolated access. It can be hosted on-premise or by a third-party cloud hosting provider. With this change in architecture UPCNet gained the flexibility of the cloud computing model--being able to create, start, stop and pause virtual computing assets for the projects and the operations, and having the option of using seamlessly assets in public clouds (like Amazon Web Services--if the necessity arises). Operating a private cloud on its DPC allows UPCNet to ensure GDPR compliance and other EU regulations in internal UPC projects like the Atenea Platform, and external projects of UPCNet's customers. For example, the UPCNet private cloud runs the Agora platform which serves independent Moodle instances for all the government primary and secondary education centers and some of the private owned ones--more than 2500 Moodle instances. On March 14, 2020, the confinement of the population throughout Spain was decreed due to the emergency caused by the COVID-19 pandemic. For the UPC, as for the rest of the state's universities, this means moving all teaching to online format overnight. The daily creation of new resources and activities immediately doubled as did most activity indicators. There was also a significant increase in workload. Internal server resources saw an 800% increase in platform stress. UPCNet technicians needed to address the workload issue by identifying bottlenecks and increasing resources dedicated to virtual machines. Some of these actions needed to be done urgently in a few weeks. Once it was clear that the confinement would last until the end of the course, Atenea officials saw that the assessments should be done online in all faculties of the UPC. There are many ways to do online assessment, ranging from the delivery of exercises, the continuous assessment of activities and practices, presentations and oral exams by video conference, etc. One of the forms of assessment is the use of test-type exams, implemented in Moodle with the Quiz module. The Moodle Quiz module allows you to define questionnaires in a very agile way. It allows you to work with various types of questions, create question banks organized by categories, create personalized exams for each student with random questions from established categories, randomize the order of answers, take self-assessment tests, make more than one attempt, and much more. This is a very complex module, with more than 100,000 lines of source code and making intensive use of the database engine. At that time, the main question was whether Atenea would be able to bear the overload once large or very large courses (\(\geq\)200 students) started doing questionnaires simultaneously. In previous simulations the UPCNet technicians discovered performance issues while doing some of the tests based on the Quiz module, and experienced some glitches during partial evaluations.