By default, Grafana uses Prometheus as a data source to provide graphs and charts. If your OpenStack version is Pike or newer and you have deployed Tenant Telemetry as described in MCP Deployment Guide: Deploy Tenant Telemetry, you can also add Gnocchi as the data source for Grafana. This allows StackLight LMA gather the data both from Prometheus and from Gnocchi, the Tenant Telemetry database, for further processing and displaying through Grafana dashboards.