Manage shard and node
Nodes are VMs (Virtual Machines) included in a cluster, and shards are groups of nodes that use the cluster configuration. Below is a guide on how to manage shards and nodes within a cluster in the MemStore service.
View shards and nodes
- When using cluster mode
- When not using cluster mode
You can view the list and status information of shards and nodes created within the cluster.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to view detailed information from the Cluster menu.
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View information in the Shard List tab.
Shard List Tab
Item Information Description Menu button Copy all endpoints Copy all node endpoints in the cluster in a line-break format. Add shard Add a shard to the cluster. Add node Add a node to a shard in the cluster. Delete shard Delete a shard in the cluster. Cannot delete if there is only one shard. Shard List Shard name Shard name is automatically assigned.
- Format:{Cluster name} + {nnn}
Status Status of the shard
- For detailed status values, refer to Cluster lifecycle and status valuesNumber of nodes Number of nodes created within the shard. Slots Slot range assigned to the shard. Uptime Uptime from the start of shard creation to the present. Created at Time when the shard was created. Node List Node name Node name is automatically assigned.
- Format:{Cluster name} + {nnn} + {nnn}
Status Status of the node
- For detailed status values, refer to Cluster lifecycle and status valuesRole Role assigned to the node
- For detailed role information, refer to NodeSubnet User subnet selected during cluster creation. AZ AZ information where the node was created. Endpoint Endpoint for cluster connection. Uptime Uptime from the start of node creation to the present. Created at Time when the node was created.
You can view the list and status information of nodes created within the cluster.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to view detailed information from the Cluster menu.
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View information in the Node List tab.
Node List Tab
Item Description Add node Add a node to the cluster. Node name Node name is automatically assigned.
- Format:{Cluster name} + {nnn}
Status Status of the node
- For detailed status values, refer to Cluster lifecycle and status valuesSubnet User subnet selected during cluster creation. Role Role assigned to the node
- For detailed role information, refer to NodeUptime Uptime from the start of node creation to the present. Created at Time when the node was created.
Manage shards and nodes (when using cluster mode)
Add shard
You can add shards to a cluster.
Adding or deleting shards involves slot movement, which may take several hours to complete.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to which you want to add a shard from the Cluster menu.
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Click the Shard List tab, then click the Add Shard button.
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In the Add Shard popup, check the selected cluster, select the subnet for nodes within the shard, and click the [Add] button.
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In the Cluster menu, the status of the cluster for which the shard addition was requested changes to
Modifying
and then changes toRunning
upon completion.
Delete shard
You can delete shards that are no longer needed from the cluster. When a shard is deleted, the nodes within the shard are also deleted, and deleted resources cannot be restored.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster from which you want to delete a shard from the Cluster menu.
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Click the Shard List tab, select the checkbox for the shard to delete, and click the Delete Shard button.
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In the Delete Shard popup, enter the name of the shard to be deleted and click the [Delete] button.
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Verify whether the shard has been deleted in the Cluster menu.
Add node
You can add nodes to a cluster. Adding a node to a shard adds a Replica node without service interruption.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to which you want to add a node from the Cluster menu.
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Click the Shard List tab, select the shard to which you want to add a node, and click the Add Node button.
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In the Add Node popup, check the selected cluster, select the subnet to be used by the node, and click the [Add] button.
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Verify whether the node has been added in the Cluster menu.
Delete node
You can delete nodes that are no longer needed without service interruption. Primary nodes cannot be deleted, and nodes cannot be deleted if the number of nodes within the shard is 2.
Deleted node resources are completely released and cannot be recovered, so please be careful.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster from which you want to delete a node from the Cluster menu.
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Click the Shard List tab, click the [More] button for the shard to delete the node from, and click the Delete node button.
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In the Delete node popup, enter the name of the node to be deleted and click the [Delete] button.
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Verify whether the node has been deleted in the Cluster menu.
Manage shards and nodes (when not using cluster mode)
Add node
You can add nodes to a cluster. Adding a node to the cluster adds a Replica node without service interruption.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to which you want to add a node from the Cluster menu.
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Click the Node List tab, then click the Add Node button.
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In the Add Node popup, check the selected cluster and click the [Add] button.
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In the Cluster menu, the status of the cluster for which the node addition was requested changes to ScalingOut, and verify whether the node has been added.
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Wait until the status of the new node changes from Provisioning to
Running
in the Node List tab on the cluster detail page.- The role of the newly added node is assigned as Replica.
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Once all node additions are complete, the status of the cluster changes to
Running
.
Promote node
If you need to change the Primary node of a running cluster, you can promote one of the Replica nodes to the Primary node. However, if high availability is enabled or if the cluster has only one node, you cannot perform node promotion.
Node promotion restrictions | Description |
---|---|
Nodes with high availability enabled | High availability automatically handles promotion, so manual promotion is not supported. |
Clusters with only one node | Clusters with only one node cannot be promoted because there is no Replica node. - Add a Replica node to the cluster first, and then perform the promotion. |
If high availability is enabled, promotion is not supported.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to promote a node from the Cluster menu.
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Click the Node List tab, click the checkbox for the node to be promoted, and then click the Promote button.
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In the Promote popup, check the node to be promoted and click the [Promote] button.
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Wait until the status of the cluster changes from
Running
to SwitchingOver. While promotion is in progress, the status of the cluster changes, but the roles of the nodes remain the same until completion. -
When the promotion is complete, the cluster status changes back to
Running
. -
In the Node List tab, check whether the role of the promoted node has changed from Replica to Primary.
- Since only one Primary node can be created, the role of the existing Primary node changes to Replica.
Delete node
You can delete nodes that are no longer needed without service interruption. Primary nodes can only be deleted when they are in a Failed state. If the Primary node is not in a Failed state, change it to a Replica node before deleting it.
Deleted node resources are completely released and cannot be recovered, so please be careful.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to which the node to be deleted belongs from the Cluster menu.
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Click the Node List tab, click the checkbox for the node to be deleted, and select Delete node.
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In the Delete node popup, enter the name of the node to be deleted and click the [Delete] button.
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While the node is being deleted, the status of the cluster changes to ScalingIn, and the status of the node being deleted changes to Terminating.
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Verify that the deleted cluster status changes back to
Running
. The deleted node is no longer displayed.