I. Introduction
Cloud monitoring and logging play an important role in cloud management system. Logs are generated from multiple data sources in cloud environment such as Physical Machines (PMs), Virtual Machines (VMs), network devices and the cloud running applications services. Each single cloud component has numerous logs and events data source generators, which could be generated from low level frameworks such as Hypervisor (the virtualization software) up to the running applications on top of the VMs. Logs must be captured and filtered or aggregated based on the need of the cloud management system, which can be used to discover cloud status and future actions for cloud management system. Cloud management models can manage the resources dynamically via reconfiguring cloud resources using numerous approaches such as VM migration, storage migration, network reconfiguration, load balancing, affinity relation, hot spot avoidance, server consolidation, holistic approach and fault tolerance [1]. These resource reconfiguration methods can be generalized in a closed loop control model proposed as following [2]: Cloud resource monitoring, logs analyzing, resource planning and finally executing the planned decisions. Figure 1 depicts the closed loop cloud management system.