Does a Redis Instance Support Expansion?
On the Redis console, you can change the capacity of an instance to meet different requirements. For more information, see Instance Lifecycle Management - Capacity Expansion.
Will Instance Expansion Affect Services?
l During instance expansion, the instance will be intermittently disconnected for 30 seconds once or twice.
l To ensure that the newly expanded instance can quickly catch up with the incremental data of the original instance and avoid dual-writing of data caused by DNS caching, each shard node of the instance will be in a read-only state for 1 minute during the expansion.
l After the expansion, the instance ID, connection address, data, trustlist configuration, and configuration of the created account and password will remain the same as before.
Can I Reduce the Capacity of a Redis Instance?
No, the capacity of a Redis instance cannot be reduced.
Can I Change the Type of a Redis Instance?
On the Redis console, you can change the type of an instance. For example, you can change a single replica to dual replicas to provide better reliability and stability. For more information, see Instance Lifecycle Management - Type Change.
What Are the Supported Instance Type Changes? What Is the Impact of the Changes?
Instance Version | Supported Instance Type Changes | Notes on Type Change and Impact |
Redis 2.8/4.0/5.0 | From stand-alone to active/standby | The instance cannot be connected for several seconds and remains read-only for about one minute. |
Redis 2.8/4.0/5.0 | From stand-alone cluster to active/standby cluster | The node cannot be connected for several seconds and remains read-only for about one minute. |
Redis 6.0/7.0 | From stand-alone to active/standby | The connection and services are not affected. |
Redis 6.0/7.0 | From stand-alone cluster to active/standby cluster | The connection and services are not affected. You are advised to add the address of the standby node to the connection address for better availability. |
Does a Redis Instance Support Version Upgrade, Such as Upgrade from Redis 4.0 to Redis 5.0?
Currently, instance upgrade is not supported.
Are Instances Stopped or Restarted During Specification Modification?
No. Specification modifications can take place while the instance is running and do not affect other operations.
Why Do I Fail to Change the Type of a Redis Instance?
You can change the type of a running Redis instance. Check whether the instance is being expanded, deleted or restarted. Try again later.
How Do I Add Shards to a Redis Cluster Instance Without Changing the Memory?
After a stand-alone cluster or an active/standby cluster instance is created, you can add more shards without changing the total memory. This operation is not supported for other types of instances.
Can I Expand a Single Shard of a Cluster Instance?
After a stand-alone cluster or an active/standby cluster instance is created, you can expand a single shard. This operation is not supported for other types of instances. For more information, see Instance lifecycle Management - Capacity Expansion.
Will Services Be Interrupted when an Instance Is Expanded or its Type Is Changed in the Maintenance Window?
Yes, services can be interrupted for a short time.
How Do I Handle an Error when I Use Lettuce to Connect to a Redis Cluster Instance After Capacity Expansion?
If the shard quantity changes after capacity expansion, some slots are migrated to new shards.
The following error occurs when you use Lettuce to connect to the instance: Connection to xxx not allowed.
For details, see Connection to X not allowed. This connection point is not known in the cluster view.
Solution: Enable automated topology refresh.
ClusterTopologyRefreshOptions topologyRefreshOptions = ClusterTopologyRefreshOptions.builder()
// Periodic refresh: every time milliseconds.
.enablePeriodicRefresh(Duration.ofMillis(time))
// MOVED redirection, ASK redirection, reconnection, unknown node (since 5.1), and slot not in any of the current shards (since 5.2).
.enableAllAdaptiveRefreshTriggers()
.build();