On the Database > Metrics page you can view detailed real-time graphs of various database metrics, as well as shard-related metrics.
You can choose which metrics are shown in each of the two detailed graphs at the top of the page, as follows: Below the top two graphs there is a group of smaller graphs that display all available metrics, such as CPU utilization and operations per second. In each of the bottom graphs, you can click the left arrow to display that metric in the top left graph, and the right arrow to display that metric in the top right graph.
You can choose which resource(s) and metric(s) are shown in each of the two detailed graphs at the top of the page, as follows: Below the top two graphs there are two groups of smaller graphs: The first group displays all available resources: the database itself, and each of the database shards. These can be master shards, slave shards (if Database replication is enabled), or shards that take part of a clustered database (for additional details, refer to Database clustering.