Rolling Restarts
When you restart multiple services, components, or hosts, use rolling restarts to distribute the task. A rolling restart stops and then starts multiple running slave components, such as DataNodes, NodeManagers, RegionServers, or Supervisors, using a batch sequence.
![[Important]](../common/images/admon/important.png) | Important |
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Rolling restarts of DataNodes should be performed only during cluster maintenance. |
You set rolling restart parameter values to control the number, time between, tolerance for failures, and limits for restarts of many components across large clusters.
To run a rolling restart, follow these steps:
From the service summary pane on the left of the Service display, click a service name.
On the service Summary page, click a link, such as DataNodes or RegionServers, of any components that you want to restart.
The Hosts page lists any host names in your cluster on which that component resides.
Using the host-level Actions menu, click the name of a slave component option, and then click Restart.
Review and set values for Rolling Restart Parameters.
Optionally, reset the flag to restart only components with changed configurations.
Click Trigger Restart.
After triggering the restart, you should monitor the progress of the background operations.
More Information
Setting Rolling Restart Parameters