Dynamic SLA Template Adjustments Based on Service Property Monitoring

Service level agreements (SLAs) are used to manifest guarantees about certain functional and non-functional aspects of service execution. Service providers are confronted with a hard problem when trying to estimate reasonable QoS levels and other default settings for SLA templates. The insufficient use of formal service behavior descriptions, varying resource demands and a choice of configuration options expected by users contribute to this issue. We present our solution of gathering monitoring data at runtime and feeding it back into the service registry to adjust descriptions and make contract template derivation a more realistic process. In addition, we show how to extend SOA building blocks such as service discoveries and SLA managers with the adjustment mechanism.