mod_reserve is an Apache2 module for Linux that extends the Apache HTTP server, allowing it to reserve a certain CPU bandwidth for the provisioning of a service. This module exploits the functionality provided by AQuoSA, whose API is used to reserve CPU bandwidth for execution of tasks. In this way, the module can force the Web server to provide services, like CGI or Perl scripts, using exactly the configured CPU bandwidth. This behaviour is useful in order to provide Quality of Service to certain types of services, or to prevent the kinds of attacks in which a service can starve all the others.
QoSDB is a QoS registry designed for supporting QoS management in realtime SOAs. It can be exploited for gathering QoS data related to different functional behaviors of the application (application operating modes) and for predicting future performance based on historical data. A modular architecture allows for defining various models for the prediction of resource requirements under a set of conditions which has not been observed yet. This allows for achieving nearly-correct resource allocation (self-configuration) for the application with a great reduction of needed observation/benchmarking points, especially in those contexts in which the space of possible configuration parameters is big (e.g., multimedia applications supporting arbitrary resolutions). By leveraging the QoSDB, SOAs can be built with auto-tuning capabilities, for better exploitation of internal resources while guaranteeing the QoS required by users.