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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​

You can view the list and status information of shards and nodes created within the cluster.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to view detailed information from the Cluster menu.

  3. View information in the Shard List tab.

    Shard List Tab

    ItemInformationDescription
    Menu buttonCopy all endpointsCopy all node endpoints in the cluster in a line-break format.
    Add shardAdd a shard to the cluster.
    Add nodeAdd a node to a shard in the cluster.
    Delete shardDelete a shard in the cluster. Cannot delete if there is only one shard.
    Shard ListShard nameShard name is automatically assigned.
    - Format: {Cluster name} + {nnn}
    StatusStatus of the shard
    - For detailed status values, refer to Cluster lifecycle and status values
    Number of nodesNumber of nodes created within the shard.
    SlotsSlot range assigned to the shard.
    UptimeUptime from the start of shard creation to the present.
    Created atTime when the shard was created.
    Node ListNode nameNode name is automatically assigned.
    - Format: {Cluster name} + {nnn} + {nnn}
    StatusStatus of the node
    - For detailed status values, refer to Cluster lifecycle and status values
    RoleRole assigned to the node
    - For detailed role information, refer to Node
    SubnetUser subnet selected during cluster creation.
    AZAZ information where the node was created.
    EndpointEndpoint for cluster connection.
    UptimeUptime from the start of node creation to the present.
    Created atTime when the node was created.

Manage shards and nodes (when using cluster mode)​

Add shard​

You can add shards to a cluster.

info

Adding or deleting shards involves slot movement, which may take several hours to complete.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to which you want to add a shard from the Cluster menu.

  3. Click the Shard List tab, then click the Add Shard button.

  4. In the Add Shard popup, check the selected cluster, select the subnet for nodes within the shard, and click the [Add] button.

  5. In the Cluster menu, the status of the cluster for which the shard addition was requested changes to Modifying and then changes to Running 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.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster from which you want to delete a shard from the Cluster menu.

  3. Click the Shard List tab, select the checkbox for the shard to delete, and click the Delete Shard button.

  4. In the Delete Shard popup, enter the name of the shard to be deleted and click the [Delete] button.

  5. 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.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to which you want to add a node from the Cluster menu.

  3. Click the Shard List tab, select the shard to which you want to add a node, and click the Add Node button.

  4. In the Add Node popup, check the selected cluster, select the subnet to be used by the node, and click the [Add] button.

  5. 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.

caution

Deleted node resources are completely released and cannot be recovered, so please be careful.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster from which you want to delete a node from the Cluster menu.

  3. Click the Shard List tab, click the [More] button for the shard to delete the node from, and click the Delete node button.

  4. In the Delete node popup, enter the name of the node to be deleted and click the [Delete] button.

  5. 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.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to which you want to add a node from the Cluster menu.

  3. Click the Node List tab, then click the Add Node button.

  4. In the Add Node popup, check the selected cluster and click the [Add] button.

  5. 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.

  6. 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.

  7. 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 restrictionsDescription
Nodes with high availability enabledHigh availability automatically handles promotion, so manual promotion is not supported.
Clusters with only one nodeClusters 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.
info

If high availability is enabled, promotion is not supported.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to promote a node from the Cluster menu.

  3. Click the Node List tab, click the checkbox for the node to be promoted, and then click the Promote button.

  4. In the Promote popup, check the node to be promoted and click the [Promote] button.

  5. 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.

  6. When the promotion is complete, the cluster status changes back to Running.

  7. 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.

caution

Deleted node resources are completely released and cannot be recovered, so please be careful.

  1. Go to KakaoCloud Console > Data Store > MemStore menu.

  2. Select the cluster to which the node to be deleted belongs from the Cluster menu.

  3. Click the Node List tab, click the checkbox for the node to be deleted, and select Delete node.

  4. In the Delete node popup, enter the name of the node to be deleted and click the [Delete] button.

  5. 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.

  6. Verify that the deleted cluster status changes back to Running. The deleted node is no longer displayed.