Create cluster
A cluster is an object composed of multiple nodes, allowing users to perform management operations such as viewing, monitoring, and deleting. Below is how to manage a cluster.
It is recommended to monitor and manage the system periodically to ensure that memory usage does not exceed 50% of the system's available memory.
The KakaoCloud MemStore service currently sets the maxmemory configuration to approximately 65% of the system's available memory. When maximum memory is reached, the allkeys-lru policy will delete the least recently used keys.
View cluster list
You can view the list of clusters created within a project.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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In the Cluster menu, check the list of currently created clusters.
Item Description Cluster name Name assigned by the user during cluster creation
- Click the cluster name to view detailed information about the clusterStatus Current status of the cluster
- For more details on status values, refer to Cluster lifecycle and status valuesEngine version Redis OSS engine version running on the node Node type Node type selected by the user during cluster creation
- Hover over the node type value to view vCPU and Memory information for that type
- For types of node types, refer to Node typeCluster mode Indicates whether cluster mode is enabled High availability Indicates whether automatic failover is enabled for node failures Automatic backup retention period Current automatic backup retention period set for the cluster
- Hover over the value to view the automatic backup start timeNumber of shards Number of shards within the cluster
- If cluster mode is not enabled, the number of shards is displayed as a hyphen (-).Number of nodes Number of nodes created within the cluster Uptime Uptime of the cluster since the creation start time
- Hover over the value to view the cluster creation dateCreator User who initially requested the cluster creation
View cluster information
You can view the information of the clusters created within a project.
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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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Check the information from the tabs.
Details tab
Item Information Description Top information Operational status Current operational status of the cluster Cluster mode Indicates whether cluster mode is enabled High availability Indicates whether automatic failover is enabled for node failures Endpoint - Primary endpoint Read/Write-enabled endpoint Endpoint - Read endpoint Read-only endpoint
- Read endpoints are not provided when cluster mode is enabledDetails - Cluster Cluster name Name assigned by the user during cluster creation Creator User who initially requested the cluster creation Cluster mode Indicates whether cluster mode is enabled High availability Indicates whether automatic failover is enabled for node failures Node type Node type selected by the user during cluster creation. Refer to Node type for details. vCPU per node Number of Virtual CPUs allocated to the node type selected by the user during cluster creation Memory per node Memory size allocated to the node type selected by the user during cluster creation Number of shards Number of shards configured in the cluster Number of nodes Number of nodes created within the cluster
- You can view the list and status of shards and nodes in the cluster in the Shard/Node List tabCreation date and time Time when the cluster creation was requested Cluster ID Object ID of the cluster Network VPC User VPC selected by the user during cluster creation Availability zone Availability zone distribution type of the cluster
- Multi: The cluster is configured across 2 or more AZs
- Single: The cluster is configured in 1 AZPrimary endpoint Read/Write-enabled endpoint Read endpoint Read-only endpoint
- Read endpoints are not provided when cluster mode is enabledPort Connection port for the node, default is 6379Backup Number of backups Number of all created backups Backup retention period Automatic backup retention period, selectable from a minimum of 1 day to a maximum of 35 days Automatic backup start time Automatic backup start time, backups start within 15 minutes of the selected time Redis compatibility settings Engine version Redis engine version running on the node License License information for the Redis OSS engine User authentication Indicates whether user authentication was enabled during cluster creation ID Administrator ID entered when user authentication is enabled
- If user authentication is not enabled, the ID is not displayedParameter group Displays the applied parameter group and the status of parameter application.
For more details, refer to Parameter application statusShard/Node list tab
Refer to How-to Guides > Manage shard and node
Security tab
Refer to How-to Guides > Create cluster > View security group
Monitoring tab
Refer to How-to Guides > Create cluster > Cluster monitoring
Cluster monitoring
The Monitoring tab allows you to check the status of nodes in detail within the cluster, enabling flexible and efficient node management while minimizing the resources required for management.
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Go to KakaoCloud Console > Data Store > MemStore menu.
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Select the cluster to be monitored in the Cluster menu.
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Click the Monitoring tab and check the information.
Monitoring tabCategory Description ① Monitoring node Select the node to be monitored ② Data period Period of data to be displayed in the monitoring graph
- 1 hour (default) / 3 hours / 12 hours / 1 day / 7 days③ View items Select items to view for monitoring
- MemStore / CPU / Memory / Network
- All items are selected by default
- Multiple items can be selected④ View mode Set the monitoring graph view mode
- 1 column, 2 columns, 3 columns provided⑤ Auto-refresh interval Set the auto-refresh interval
- No auto-refresh (default) / 10 seconds / 30 seconds / 1 minute / 5 minutes⑥ Manual refresh Click to manually refresh the monitoring results
Provided monitoring data
Category Monitoring data Description MemStore Command calls (Count/sec) Number of command calls per second over time MemStore Connections (Count) Number of connections over time
- Max connections: Maximum number of clients that can be connected
- Active connections: Number of currently connected clientsMemStore Cache hit ratio (%) Redis hit ratio over time MemStore Expired and evicted keys (Count) Number of expired and evicted keys over time CPU Total usage (%) Total CPU usage over time Memory Total usage (%) Total memory usage over time Memory Usage by type (Bytes) Memory usage by type over time Network RX by interface (Bytes/sec) Network RX usage per second over time Network TX by interface (Bytes/sec) Network TX usage per second over time Network RX by interface (PPS) Network RX packet usage per second over time Network TX by interface (PPS) Network TX packet usage per second over time
Configure High availability
The MemStore service provides high availability features to ensure convenience and stable operation for users.
When high availability is enabled, the service automatically takes action in the event of a node failure. High availability can be enabled without a separate service interruption. However, the cluster must be in Running status and have at least 1 Replica node to enable high availability.
When cluster mode is enabled, the cluster uses high availability by default, and settings cannot be changed.
- Go to KakaoCloud Console > Data Store > MemStore menu.
- In the Cluster menu, select the [More] icon for the cluster to enable high availability, and select Configure HA.
- Configure the high availability settings and click the [Save] button.
- Check the high availability status on the cluster's detail page to confirm that it has been updated correctly.
Delete cluster
You can delete clusters that are no longer needed.
Resources of the deleted cluster will be completely returned after termination and cannot be restored, so proceed with caution.
- Go to KakaoCloud Console > Data Store > MemStore menu.
- In the Cluster menu, select the [More] icon for the cluster group to be deleted, and select Delete cluster.
- In the popup, enter the name of the cluster to be deleted and click the [Delete] button.
MemStore user account
The MemStore service provides a user authentication option for users. When user authentication is enabled, users can access resources using the ID and password they set. If not enabled, access to resources is allowed using the default account without a password.
User authentication is not supported for Redis OSS engine versions 5 or lower.
Command restrictions
To ensure smooth service operation and management, the following commands are restricted. Attempting to use them will return a NOPERM error.
If there are many keys stored in the instance, using the keys, flushall, or flushdb commands may cause the instance to crash.
- When cluster mode is enabled
- When cluster mode is disabled
| Command | Description |
|---|---|
| ACL | ACL-related commands |
| BGREWRITEAOF | Rewrite AOF file |
| BGSAVE | Background save |
| CLIENT PAUSE | Pause client |
| CLUSTER ADDSLOTS | Add slots |
| CLUSTER BUMPEPOCH | Increment cluster epoch |
| CLUSTER DELSLOTS | Remove slots |
| CLUSTER FAILOVER | Cluster failover |
| CLUSTER FLUSHSLOTS | Flush slots |
| CLUSTER FORGET | Disconnect nodes |
| CLUSTER MEET | Connect cluster nodes |
| CLUSTER REPLICATE | Replicate cluster node |
| CLUSTER RESET | Reset cluster |
| CLUSTER SAVECONFIG | Save cluster configuration |
| CLUSTER SET-CONFIG-EPOCH | Set cluster configuration epoch |
| CLUSTER SETSLOT | Change slot configuration |
| CONFIG | Configure Redis OSS |
| DEBUG | Debugging commands |
| FAILOVER | Failover commands |
| MIGRATE | Data migration |
| MODULE | Module-related commands |
| PSYNC | Check replication status |
| REPLCONF | Change replication settings |
| REPLICAOF | Set slave |
| RESTORE-ASKING | Request data restore |
| SAVE | Save data |
| SHUTDOWN | Shutdown Redis |
| SLAVEOF | Set master |
| SORT | Sort commands |
| SYNC | Synchronization commands |
| Command | Description |
|---|---|
| ACL | ACL-related commands |
| BGREWRITEAOF | Rewrite AOF file |
| BGSAVE | Background save |
| CLIENT PAUSE | Pause client |
| CLUSTER | Cluster-related commands |
| CONFIG | Configure Redis OSS |
| DEBUG | Debugging commands |
| FAILOVER | Failover commands |
| MIGRATE | Data migration |
| MODULE | Module-related commands |
| PSYNC | Check replication status |
| REPLCONF | Change replication settings |
| REPLICAOF | Set slave |
| RESTORE-ASKING | Request data restore |
| SAVE | Save data |
| SHUTDOWN | Shutdown Redis |
| SLAVEOF | Set master |
| SORT | Sort commands |
| SYNC | Synchronization commands |
View security group
In the Security tab of the cluster's details, you can view the Security Group and detailed policies applied to the cluster.
To access the cluster, port 6379 must be allowed in the Security Group.
Click on the name of the connected Security Group in the list to navigate to the VPC > Security Group details page for policy management.
Security Group connection information management and Inbound/Outbound policy management within the Security tab of the detailed information will be provided in the future.
Access MemStore cluster
There are several methods to access the cluster from an instance in the MemStore service.
After completing the cluster creation and configuration, you need to connect the instances created along with the cluster using a Redis Client.
Prerequisites
To connect to the cluster, you need a Virtual Machine instance (node) using the same network as the cluster to connect and an accessible connection environment for the cluster's endpoint.
To do this, you must allow TCP 6379 (default cluster port number) in the Outbound policy of the Virtual Machine instance's Security Group.
Connect to cluster
You can access the cluster from the instance.
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Refer to Virtual Machine > Create and connect instance for details on accessing the instance and preparing the Redis Client. If Redis commands are not recognized, you need to install a separate Redis Client.
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Go to the MemStore menu on the KakaoCloud Console.
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Select the cluster to connect to from the Cluster menu.
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Check the Endpoint in the Details tab. This information is required for executing Redis commands. Copy it to your clipboard or save it for reference.
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Run the Redis connection command from the instance to access the cluster.
Redis instance connection commandredis-cli -h {ENDPOINT} -p {PORT_NUMBER} {COMMAND}Item Description {ENDPOINT}Endpoint information obtained from the Details tab {PORT_NUMBER}Port number for Redis connection, default is 6379
For more details on the roles and types of instances, refer to Instance.
Change parameter group
You can change the parameter group associated with the cluster.
The parameter group corresponding to the cluster's engine version and cluster mode can be selected. If changing the parameter group affects the values of parameters already set, it may impact the operational MemStore service, so it is recommended to review the parameter values of the parameter group to be changed in advance. If a parameter group change is already in progress, the change request may fail.
Refer to Create and Manage Parameter Groups for more details.
- Go to KakaoCloud Console > Data Store > MemStore menu.
- In the Cluster menu, select the [More] icon for the cluster to change the parameter group, and select Change parameter group.
- In the popup, select the parameter group to be changed and click the [OK] button.