EucaBomber: Experimental Evaluation of Availability in Eucalyptus Private Clouds

Cloud computing is a computational paradigm with increasing adoption because it offers resources as services in a dynamically scalable way through the Internet. The constant concern in providing cloud computing services in a reliable and uninterrupted manner inspires availability and reliability studies. A feasible method of performing such studies is through automated fault injection, enabling to observe the behavior of the cloud architecture under many conditions. This paper presents a fault injection tool, named EucaBomber, for reliability and availability studies in the Eucalyptus cloud computing platform. EucaBomber allows to define the probability distribution associated to the time between generated events. The efficiency of EucaBomber is verified through testbed scenarios where faults and repairs are injected in a private Eucalyptus cloud. The experimental results are cross-checked with results estimated from a Reliability Block Diagram, using the same input parameters of the experimental testbed. The test scenarios also illustrate how the tool may assist cloud systems administrators and planners to evaluate the system's availability and maintenance policies.