 measurements reported are collected via ONAP. In addition, vProbes should generate self-monitoring stats, both for health and performance to enable resilient orchestration. 16.8.3 ACTIVE VPROBE MEASUREMENTS DATA MODEL Active probe monitoring is a measurement process that injects synthetic transactions into a system or network and monitors the flow of those transactions to detect anomalies, or measures specific performance or availability that can be used for SLA reporting. This is helpful for a simple connec- tivity testing or performance testing; for example, timing the latency between two hosts operating in the same cloud zone connected via an overlay SDN local controller and leaf-spine underlay, as well as more complex analytical tasks such as collecting measurements to verify QoS and whether availability objectives are being met. NFV implementations in cloud environments often encounter performance degradation or fail- ures (known as gray failures) where either the problem is not detectable by traditional passive mea- surements, or the software component does not properly report impairments. These gray failures could silently impair the NFV tenant by causing loss of network or resource connectivity, loss of privileges or lead to operation in a degraded state. Active probes behaving as tenants and generating synthetic heart beats that alarm when the heart beat is impaired, enable operators to get proactive notification of tenant impact. As is the case with VNFs, orchestrated deployment of active vProbes is facilitated through the use of heat-orchestration templates and the placement of active probes as well as configuration of probe heart beat frequency, which is administered using a centralized management function. Active vProbes once deployed, are controlled by the service orchestrator through the API and all measure- ments and alarms reported are collected via ONAP. 16.9 VNF REPORTING METRICS VNF developers have responsibility to report and log key measurements on VNF transactions as well as key event noti