ABSTRACT
The adoption of Cloud computing in the last years has increased notably [487] [153]. Cloud computing has had a major commercial success over recent years and will play a large part in the ICT domain over the next 10 years or more [487]. However, there are still major limitations which current Cloud computing solutions are not yet able to address adequately. Among others, the difficulties to provide guaranteed levels of service (also known as Quality of Service, QoS) for all kind of applications is one of the major barriers for the adoption of this technology by a wider range of users. One of the main reasons is the lack of a complete monitoring solution which provides information at all levels of the environment, from application, to platform, down to the physical infrastructure. The existence of an integrated monitoring infrastructure within the Cloud environment would bring benefits to both users and providers of Cloud services in their different delivery models (Infrastructure-as-a-Service, Platform-as-a-Service and Software-as-a-Service) [54]. A well designed monitoring infrastructure is crucial to provide and guarantee most of the essential features of Cloud computing, such as accounting and billing (which allows the pay-per-use model), access control (contribution towards trust and security mechanisms), resource planning and optimization (crucial to fulfill the Cloud provider business interests), elasticity (allowing to scale resources as needed by the user application) and Service Level Agreements (SLAs) (the more complete the monitoring solution, the more fine-grained the SLA can be, which gives the user of the Cloud solution the chance to run more demanding applications on the Cloud, in terms of QoS requirements). This chapter analyzes the requirements of an efficient monitoring mechanism for Cloud environments. Furthermore, it presents an analysis of different existing approaches for collecting monitoring information at different levels of Cloud based platforms, and compares different monitoring tools and solutions available (both commercial and open source). Finally, it elaborates a proposal on how a full monitoring solution should be designed and implemented, in order to serve the needs and business interests of different Cloud computing stakeholders (users and providers of different delivery models).
