Monitor Service Performance: This action monitors a user-specified set of run-time performance conditions for a virtual service, and sends alerts to a specified destination when these performance conditions are violated.

Monitor Service Level Agreement: This action provides the same functionality as Monitor Service Performance, but this action is different because it enables you to monitor a virtual service's run-time performance for particular consumers. You can configure this action to define a Service Level Agreement (SLA), which is set of conditions that defines the level of performance that a specified consumer should expect from a service.

Throttling Traffic Optimization: This action limits the number of service invocations allowed during a specified time interval, and sends alerts to a specified destination when the performance conditions are violated. You can use this action to avoid overloading the back-end services and their infrastructure, to limit specific consumers in terms of resource usage, etc.