Instance states and impacts - ApsaraDB for Redis - Alibaba Cloud Documentation Center

This topic describes the different states of an ApsaraDB for Redis instance to help you manage your instances. When you restart or change the configurations of an instance, the state of the instance changes. This may cause impacts such as a transient connection that lasts for a few seconds.

Instance states

You can query the state of an instance by using the following methods:

Use the ApsaraDB for Redis console: You can view the state of an instance on the Instances page of the ApsaraDB for Redis console.
Call an API operation: You can call the DescribeInstances operation to query the state of an instance.


Console	API	Operation that leads to the state	Description
Creating	Creating	Create an ApsaraDB for Redis instance	After you create an instance, the instance enters this state. The instance cannot provide database services until the instance enters the Running state.
Running	Normal	N/A	The instance can provide database services in this state.
Converting	Transforming	Change the billing method to subscription	After you change the billing method of the instance to subscription, you cannot change the billing method back to pay-as-you-go. Before you change the billing method, we recommend that you evaluate your business requirements to make better use of the instance.
Changing Configuration	Changing	Change the configurations of an instance	For more information, see Change process and impact.
Changing Configuration	Changing	Adjust the number of shards for an ApsaraDB for Redis instance with cloud disks	Changes to the configurations of the instance may cause unstable latency. However, ApsaraDB for Redis supports scaling without leading to transient connections or the read-only state. We recommend that you perform this operation during off-peak hours and make sure that your application can automatically reconnect to the instance.
Restarting	Rebooting	Restart one or more ApsaraDB for Redis instances	A transient connection occurs on the instance. We recommend that you perform this operation during off-peak hours and make sure that your application can automatically reconnect to the instance.
Updating	MajorVersionUpgrading	Upgrade the major version	When you apply for resources, upgrade the replica node, or synchronize data, your ApsaraDB for Redis service remains available. When you switch your workloads over from the original instance to a new instance or from the master node to the replica node in the original instance, you may experience transient connections that last for a few seconds. The original instance stays in the read-only state for up to 60 seconds until all data is synchronized. We recommend that you upgrade the original instance during off-peak hours. After the upgrade is complete, the instance ID, endpoint, data, whitelist settings, accounts, and account passwords remain unchanged. Make sure that your application can automatically reconnect to your instance. If the original instance runs Redis 4.0, Bloom filter-related API operations such as BF.ADD are no longer supported after you upgrade the major version of the original instance to a version later than Redis 4.0. Note Bloom filter-related API operations are for internal use only in existing instances that run Redis 4.0 and are no longer available for new instances that run Redis 4.0 or later. If you call Bloom filter-related API operations on the new instances, you cannot perform cache analytics and unknown errors may occur. We recommend that you change the original instance into an Enhanced Edition (Tair) DRAM-based instance to use the optimized Bloom filters. For more information about DRAM-based instances, see DRAM-based instances.
Upgrading Minor Version	MinorVersionUpgrading	Update the minor version
Configuring Network	NetworkModifying	Change the network type from classic network to VPC	After you switch the network type of an instance from classic network to VPC, you cannot switch back to classic network. The instance may experience a transient connection of a few seconds. We recommend that you perform this operation during off-peak hours and make sure that your applications can automatically reconnect to the instance. When you switch the network type, you can specify whether to retain the classic network endpoint of the instance. If you do not retain the classic network endpoint, the endpoint is released after the network type is switched. Then, clients cannot connect to the instance by using the classic network endpoint. In this case, you must change the database endpoint on your client at the earliest opportunity.
		Change the endpoint or port number of an instance	Clients can no longer connect to the instance by using the original endpoints. Update the connection information on the clients at the earliest opportunity.
		Apply for a public endpoint for an ApsaraDB for Redis instance	No impact.
		Release a public endpoint for an ApsaraDB for Redis instance	Clients can no longer connect to the instance by using the original public endpoint. Update the connection information on the clients at the earliest opportunity.
		Enable the direct connection mode	If you enable the direct connection mode, you cannot perform the following operations: Change the configurations of an instance Upgrade the major version Migrate an instance across zones You must release the private endpoint before you can perform the preceding operations.
		Release a private endpoint for an ApsaraDB for Redis instance	Clients can no longer connect to the instance by using the original private endpoint. Update the connection information on the clients at the earliest opportunity.
Configuring SSL	SSLModifying	Configure SSL encryption	The instance restarts after you enable SSL encryption or update the certificate validity period. A transient connection occurs on the instance. We recommend that you perform this operation during off-peak hours and make sure that your application can automatically reconnect to the instance.
Modifying TDE	TEDModifying	Enable TDE	No impact.
Migrating to Another Zone	ZoneMigrating	Migrate an instance across zones	A transient connection occurs on the instance. We recommend that you perform this operation during off-peak hours and make sure that your application can automatically reconnect to the instance. If you migrate an instance across zones, the virtual IP address (VIP) of the instance such as 172.16.88.60 is changed. However, the endpoint of the instance remains unchanged. We recommend that you connect to the instance by using the endpoint. If you use a VIP to connect to the instance, the connection fails. If the minor version of the instance is outdated, the system updates it to the latest version to ensure high performance and stability.
Flushing Instance	Flushing	Delete data	If you choose to delete all data, take note of the following impacts: The instance runs the FLUSHALL command to delete all data from the instance. The deleted data cannot be restored. This operation immediately deletes all data from the instance and can affect your online services. Proceed with caution. We recommend that you perform this operation during off-peak hours.
Deleting Expired Data	CleaningUpExpiredData	Delete data	If you choose to delete expired data, take note of the following impacts: The instance runs the SCAN command to delete all the expired data from the instance. The deleted data cannot be restored. This operation immediately deletes all the expired data from the instance and can affect your online services. Proceed with caution. We recommend that you perform this operation during off-peak hours.
Switching	HASwitching	Manually switch workloads from a master node to a replica node	The data nodes on which the switchover is performed are disconnected for a few seconds. A switchover has potential data loss risks. For example, the data may become inconsistent between the master and replica nodes due to synchronization latency. To prevent potential data loss risks caused by the switchover and data doublewrite caused by the Domain Name System (DNS) cache, the data nodes become read-only for up to 30 seconds. After an instance enters the Switching state, you cannot manage this instance. For example, you cannot modify the instance configurations or migrate the instance to another zone.
Disabled	Inactive	N/A	The instance expires and cannot provide database services. If you want to continue using the instance, you must manually renew the instance. For more information, see Renewal.
Released	N/A	Manually or automatically release an instance that is overdue or expired	The instance is released and cannot provide database services. The instance is not displayed on the Instances page. If you want to continue using the instance, you can find and restore the instance from the recycle bin. For more information, see Manage instances in the recycle bin.