Slides for AMI CHEP presentation: Looking back on 10 years of the ATLAS Metadata Interface. Reflections on architecture, code design and development methods.

. The “ATLAS Metadata Interface” framework (AMI) has been developed in the context of ATLAS, one of the largest scientific collaborations. AMI can be considered to be a mature application, since its basic architecture has been maintained for over 10 years. In this paper we describe briefly the architecture and the main uses of the framework within the experiment (TagCollector for release management and Dataset Discovery). These two applications, which share almost 2000 registered users, are superficially quite different, however much of the code is shared and they have been developed and maintained over a decade almost completely by the same team of 3 people. We discuss how the architectural principles established at the beginning of the project have allowed us to continue both to integrate the new technologies and to respond to the new metadata use cases which inevitably appear over such a time period

Looking back on 10 years of the ATLAS Metadata Interface: reflections on architecture, code design and development methods

International audienceThe "ATLAS Metadata Interface" framework (AMI) has been developed in the context of ATLAS, one of the largest scientific collaborations. AMI can be considered to be a mature application, since its basic architecture has been maintained for over 10 years. In this paper we describe briefly the architecture and the main uses of the framework within the experiment (TagCollector for release management and Dataset Discovery). These two applications, which share almost 2000 registered users, are superficially quite different, however much of the code is shared and they have been developed and maintained over a decade almost completely by the same team of 3 people. We discuss how the architectural principles established at the beginning of the project have allowed us to continue both to integrate the new technologies and to respond to the new metadata use cases which inevitably appear over such a time period

Evolution of the architecture of the ATLAS Metadata Interface (AMI)

International audienceThe ATLAS Metadata Interface (AMI) is now a mature application. Over the years, the number of users and the number of provided functions has dramatically increased. It is ne-cessary to adapt the hardware infrastructure in a seamless way so that the quality of service re-mains high. We describe the evolution from the beginning of the application life, using one server with a MySQL backend database, to the current state in which a cluster of virtual ma-chines on the French Tier 1 cloud at Lyon, an Oracle database also at Lyon, with replication to Oracle at CERN and a back-up server are used

Monitoring of computing resource utilization of the ATLAS experiment

Due to the good performance of the LHC accelerator, the ATLAS experiment has seen higher than anticipated levels for both the event rate and the average number of interactions per bunch crossing. In order to respond to these changing requirements, the current and future usage of CPU, memory and disk resources has to be monitored, understood and acted upon. This requires data collection at a fairly fine level of granularity: the performance of each object written and each algorithm run, as well as a dozen per-job variables, are gathered for the different processing steps of Monte Carlo generation and simulation and the reconstruction of both data and Monte Carlo. We present a system to collect and visualize the data from both the online Tier-0 system and distributed grid production jobs. Around 40 GB of performance data are expected from up to 200k jobs per day, thus making performance optimization of the underlying Oracle database of utmost importance