Each unit of the system is monitored through a set of KPIs. KPIs are quantities that evolve over time. The SLA-M provides northbound entities with mechanism for accessing a current snapshot of such quantities (instantaneous KPIs) in aggregated or non-aggregated form. In addition, it keeps a history of a user-set number of the most recent KPI samples.
Refer to USP KPI Descriptions for a listing and description of KPIs supported in this release.
Two kinds of KPIs are collected:
Basic (non-aggregated) KPIs:
These are performance indicators at the VDU level which are provided to the SLA-M by either the CF or the VFNM Proxy Function.
The LCM provides all basic KPIs coming from the NFVI/VIM (for example, host/guest CPU load, memory, etc.), while the CF provides all other basic KPIs such as application specific metrics and process level information.
The following non-aggregate KPIs are provided by the CF to the SLA-M:
Performance KPIs for each constituent VDR (/vnfrs/vnfr/deployment-flavor-record/element-group-records /element-group-record/constituent-vdrs/constituent-vdr/performance-stats).
The contribution of the Performance KPIs for each constituent VDR to a specific Network Path (/vnfrs/vnfr/deployment-flavor-record/element-group-records/element-group-record/service-function-chain - records/service-function-chain-record/network-fwd-path-records/network-fwd-path-record/vdr-stats/vdr-stat).
Flow Cache KPIs for each constituent VDR (/vnfrs/vnfr/deployment-flavor-record/element-group- records/element- group-record/constituent-vdrs/constituent-vdr/flow-cache-stats).
The following non-aggregate KPIs are provided by the VNFM-proxy to the SLA-M:
These are indicators derived by SLA-M from the basic KPIs and that reflect the performance of a group of VDUs.
The SLA-M builds aggregated KPIs at different levels of the grouping hierarchy by leveraging topology information. A typical example is building network throughput at the service chain level or slice level or system level. Note that while the SLA-M has the responsibility to build the aggregated KPI, it relies on other components to get the topology that drive such aggregation.
Starting from the non-aggregate KPIs described above, the SLA-M builds the following aggregated KPIs:
Performance KPIs aggregated at:
Network Path (/vnfrs/vnfr/deployment-flavor-record/element-group-records/element-group-record /service-function-chain-records/service-function-chain-record/network-fwd-path-records/network-fwd-path -record/performance-stats)
Service Function Chain (/vnfrs/vnfr/deployment-flavor-record/element-group-records/element-group -record/service-function-chain-records/service-function-chain-record/performance-stats)
Element Group (/vnfrs/vnfr/deployment-flavor-record/element-group-records/element-group-record/performance-stats)
Vnf for specific Service Function Chain (i.e. Performance-stats for a given service-function-chain across all the element-groups) (/vnfrs/vnfr/service-function-chain-records/service-function-chain-record/performance-stats)
Flow Cache KPIs aggregated at:
NFVI KPIs aggregated at: