Monitoring with MonAMI: a case study.

Computing resources in HEP are increasingly delivered utilising grid technologies, which presents new challenges in terms of monitoring. Monitoring involves the flow of information between different communities: the various resource-providers and the different user communities. The challenge is providing information so everyone can find what they need: from the local site administrators, regional operational centres through to end-users. To meet this challenge, MonAMI was developed. MonAMI aims to be a universal sensor framework with a plugin architecture. This plugin structure allows flexibility in what is monitored and how the gathered information is reported. MonAMI supports gathering statistics from many standard daemons, such as MySQL and Apache, and system data, such as network sockets and memory consumption. The gathered data can be sent to many monitoring systems, including Ganglia, Nagios, MonaLisa and R-GMA. This flexibility allows MonAMI to be integrated into whatever monitoring system is being used. This avoids the current duplication of sensors and allows the gathered statistics to be presented within a greater diversity of monitoring systems. Using the MonAMI framework, sensors have been developed for the DPM and dCache storage systems, both common at HEP grid centres. The development of these tools specifically to tackle the challenges of high availability storage is described. We illustrate how MonAMI’s architecture allows a single sensor to both deliver long term trend information and to trigger alarms in abnormal conditions. The use of MonAMI within the ScotGrid distributed Tier-2 is examined as a case study, illustrating both the ease with which MonAMI integrates into existing systems and helps provide a framework for extending monitoring where necessary