Review Replica Set Clusters
A replica set in MongoDB is a group of
mongod processes that maintain the same data set.
Monitor cluster metrics to identify performance issues and determine whether your current cluster meets your requirements. For more information on the metrics available to monitor your clusters, see Review Available Metrics.
View Replica Set Metrics
To return the metrics for a database on a replica set's specified host using the Atlas CLI, run the following command:
atlas metrics databases describe <hostname:port> <databaseName> [options]
To list available databases for the replica set's specified host using the Atlas CLI, run the following command:
atlas metrics databases list <hostname:port> [options]
To learn more about the syntax and parameters for the previous commands, see the Atlas CLI documentation for atlas metrics databases describe and atlas metrics databases list.
To view the metrics for a specific Atlas cluster in the Clusters view of a project, click the View Monitoring button for that cluster. Alternatively, click on the name of the cluster to open the cluster overview, then click the Metrics tab. You can look at your replica set holistically, or hone in on a specific node.
The Metrics view in the Atlas UI has three distinct sections:
Note
Monitoring Data Storage Granularity
Atlas stores metrics data at increasing granularity levels. For more information, see Monitoring Data Storage Granularity.
Chart Controls
Atlas provides the following controls for the Metric view. Adjusting any of these options affects all charts displayed under the Metrics view:
Control | Function |
|---|---|
Granularity | Modifies the granularity of metrics displayed for each chart.
Select a granularity, usually between 1 minute and 1 day (24
hours). Select Atlas supports a 10 second granularity only on |
Zoom | Modifies the date range of metrics displayed for each chart.
Select a zoom range between 1 hour and 5 years. Adjusting
the Zoom automatically adjusts the
Current Display date range. |
Current Display | Modifies the start and end date-time range of metrics displayed
for each chart. Modifying the start and end date sets the
value of Zoom to custom and overrides the
previously selected zoom level. |
Toggle Members | Limit charts to the selected replica set members. The
When a secondary member needs to replicate data to catch up with the primary node, it enters the recovering state.
For information on all member states, see Replica Set Member States. |
Add Chart | Select one or more charts to display or hide. Adding
charts using this dropdown is identical to adding charts
from the Toggle Charts section of the
Metrics view. |
Display Opcounters on Separate Charts | Directs Atlas to split the Opcounters
chart into its individual components. You can then choose
to chart one or more of those components. |
Display Timeline Annotations | Directs Atlas to display or hide chart annotations.
Chart annotations consist of colored vertical lines that
indicate server events, such as a server restart or
a transition in member state. |
Chart Display
When viewing charts, you can do the following:
Task | Action |
|---|---|
View a detailed description of a chart. | Hover your mouse over the chart to display the context menu. Click next to the chart name to open the Chart Info modal. This modal includes a breakdown of the chart's data series, the annotations available for that chart, and the operations the chart supports. |
Expand a chart. | Hover your mouse over the chart to display the context menu. Click the two-way arrow at the top right of the chart. |
Zoom in on a period of time. | Click and drag the mouse pointer over a portion of the chart. To reset to the originally selected range (zoom out), double-click the chart. When you zoom in on one period of time, the Current Display date range in the chart control section automatically updates to reflect the selected period. |
View statistics at a particular time. | Hover the mouse pointer over a point on the chart. |
Move a chart. | Click and hold the grabber in the upper left corner of the chart,
and drag the chart to the new position. |
Share a URL to the chart. | Hover your mouse over the chart to display the context menu. Click the curved arrow on the chart. Select Chart Permalink to retrieve a URL to the chart. Select Email Chart to email the chart. The recipient of the chart URL must have a Atlas user account with access to the project and cluster. |
Chart Selection
Atlas displays the available metrics to chart for the selected cluster under the Toggle Charts header. Metrics are grouped into two sections:
- MongoDB Metrics
Metrics associated with the MongoDB process. For metrics related to database performance, such as DB Storage, Atlas presents the sum total across all databases in the cluster.
Note
Atlas retrieves database metrics every 20 minutes by default but adjusts frequency when necessary to reduce the impact on database performance.
If you enable Display Opcounters on Separate Charts, Atlas replaces the Opcounters option with the individual components of that chart.
- Hardware Metrics
Metrics associated with the host machines supporting the cluster.
Charts marked with the
+symbol are inactive, while charts marked with the-symbol are active. Click on any chart to toggle the chart state.