Draining a node
About this task
Drain a node using the Drain option in OpsCenter Nodes administration. Draining a node flushes all memtables from the node to SSTables on disk. Restarting DSE after draining a node is required for the node to start accepting writes again. Typically, a node is drained before upgrading to a new version of DSE.
For information about manually draining a node, see the corresponding nodetool drain command.
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Draining a node is not necessary with either the OpsCenter UI or the drain nodetool command when upgrading a node to a minor DSE version using LCM. |
To simply flush memtables to disk, use the Flush option in OpsCenter or the corresponding nodetool flush command.
Prerequisites
If OpsCenter role-based security is enabled, be sure that the permission for the Drain option in Node Operations is enabled for the appropriate user roles.
Procedure
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Click cluster name > Nodes.
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In the Ring or List view, select the node.
The Node Details dialog appears.
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From the Actions menu, click Drain..
The Drain Node dialog prompts you to confirm the operation.
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Click Drain Node.
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When the drain operations completes, perform the operation that required draining the node, such as upgrading a node manually.
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Click Restart from the Node Actions menu.
The node cannot accept writes until DSE is restarted.
The Restart DSE dialog appears.
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Click Restart DSE. It is not necessary to select the Drain before stopping option again.
