The IT infrastructure for distributed applications is getting bigger and more complex every day. Through this, the pure mass of observed events is growing. To be able to ensure a safe IT operation, we also need a distributed and scalable monitoring architecture to evaluate these events. This session wants to show how to build an architecture upon open source software. Starting with some basics on monitoring IT infrastructure and applications, we will have a look on some of the key words like monitoring, alerting, diagnostic and reporting. Based on this, we will start to build up a monitoring architecture. We will elaborate on and integrate the following modules: log file shipping and analysis (logstash), system monitoring (collectD), event storage (elasticsearch), metric generator and storage (statsd and graphite) as well as different dashboards (grafana, seyren, kibana).