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Cache for Redis

Overview

Constraints and limits

This topic summarizes the account quotas, the data types, and the limits related to some features of Cache for Redis.

Account quota

The Volcano Engine platform sets default quotas for each service in every root account. The quotas related to services of Cache for Redis in the root account of Volcano Engine are listed in the table below.

Quota item	Description
Number of instances	Each Volcano Engine root account can purchase a maximum of 50 instances by default in each region. tip After the number of existing Redis instances under the account reaches the quota limit, the following operations will prompt an error indicating insufficient instance quota: Create instance Purchasing instance with same configuration Recovery from backup set Recovery by time point Restoring deleted instance If you need to adjust the quota to purchase more instances, please go to the Quota center to submit a Quota application.
Number of nodes	Each account can create 4 nodes with a specification of 256 MiB by default in each region, and there is no limit on the number of nodes with other specifications. tip After the number of existing 256 MiB nodes under the account reaches the quota limit, if any of the following operations involve increasing or changing the specification of 256 MiB nodes, an error indicating insufficient node quota will be prompted: Create instance Purchasing instance with same configuration Recovery from backup set Recovery by time point Restoring deleted instance Modifying number of nodes Modifying number of shards Modifying node specifications If you need to adjust the quota to purchase more nodes with a specification of 256 MiB (the adjustable quota limit for each account in each region is 10), please go to the Quota center to submit a Quota application.

Data type limits

Data type	Limit
String	A single String type value cannot exceed 512 MiB.
List	List and number of its elements do not exceed 2^32-1. The value of a single element cannot exceed 512 MiB. The recommended number of elements in the List is less than 8192. The max length of the value cannot exceed 1 MiB.
Set	Set and number of its elements do not exceed 2^32-1. The value of a single element cannot exceed 512 MiB. The recommended number of elements in the Set is less than 8192. The max length of the value cannot exceed 1 MiB.
ZSet	ZSet and number of its elements do not exceed 2^32-1. The value of a single element cannot exceed 512 MiB. The recommended number of elements in the ZSet is less than 8192. The max length of the value cannot exceed 1 MiB.
Hash	Hash and number of its elements do not exceed 2^32-1. The value of a single element cannot exceed 512 MiB. The recommended number of elements in the Hash is less than 8192. The max length of the value cannot exceed 1 MiB.

Feature limits

Feature	Limit
Redis command support and limit	For more information, refer to Supported commands and Command limits.
Default disable command	Cache for Redis instances disable the flushall, flushdb, and keys commands by default. tip To use the above commands, remove the corresponding commands from the default value of the parameter disabled-commands. For specific procedures, refer to Setting instance parameters.
Deletion policy for stale data	Cache for Redis supports the following policies: Auto delete: The system backend periodically detects and automatically deletes expired keys. Manual delete: If an expired key is not deleted by the system backend, you can manually delete it.
Reclaim mechanism for idle connections	The server does not actively reclaim Redis idle connections. The user must manage it.
Data persistence policy	AOF persistence policy is enabled for primary-secondary instances by default. tip Single-node instances do not have data persistence capabilities and do not support any data persistence policies. For more information on the functional characteristics of primary-secondary and single-node instances, refer to Feature differences. Each Redis instance supports saving AOF files of the same size as the instance memory. For example, if the instance memory is 1 GiB, up to 1 GiB of AOF files can be saved in the instance and any portion exceeding 1 GiB will be deleted.
Monitoring and alerts	Cache for Redis has no services for capacity alerts. If you need to use the alert service, please configure it in Cloud Monitor. For configuration methods, refer to Creating alarm strategy.
Number of available DBs	Each Redis instance can use up to 256 databases.
Number of shard(s)	Each Redis instance with sharding cluster enabled has up to 256 shards.
Total instance nodes	Total instance nodes: total nodes per instance = number of shards × nodes per shard. The current instance has a maximum of 256 shards. Each shard can be configured with up to 6 nodes, allowing a single instance to have a maximum of 1536 total nodes. If your instance requires more nodes, submit a ticket to contact technical support to modify the relevant parameters.
IP allowlist	Each Volcano Engine account can create up to 1,000 allowlists per region. Each Volcano Engine account can allow up to one default allowlist per region. A newly created default allowlist will automatically override the existing default allowlist. That is, the existing default allowlist will automatically become a non-default allowlist. Each allowlist can be associated with up to 200 instances at a time, and there is no limit to the total number of instances that can be associated. Each allowlist can be associated with up to 300 IP addresses or IP address segments in CIDR format. Each allowlist can be associated with up to 10 ECS security groups. Each instance can be associated with a maximum of 100 allowlists. A maximum of 100 allowlists can be associated at a time. Each instance can be associated with up to 1,000 IP addresses or IP address segments in CIDR format. If no allowlist is associated with an instance, its access is denied to all addresses.
Connections	For each instance of Cache for Redis or each shard in the instance, 10,000 concurrent connections can be created every time. Requests for new connections are rejected over this limit. If you need to use more connections, you can modify the maximum number of connections. For specific procedures, refer to Modifying maximum number of connections.
Concurrent connections	For each instance of Cache for Redis or each shard in the instance, 10,000 concurrent connections can be created every time. Requests for new connections are rejected over this limit.
Bandwidth	Redis instances of different specifications support different upstream and downstream bandwidths. For more information, refer to Instance specifications. High network input and output bandwidth utilization of the instance can cause request response latency and may even lead to errors such as IO timeouts. For more information on bandwidth utilization monitoring, refer to Monitoring metrics.
Number of customized parameter templates	Each root account of Volcano Engine can create up to 20 customized parameter templates in each region by default. For more information, refer to Creating parameter template.
Number of instances of parameter templates that can be applied in batches at a time	Each parameter template can be applied to up to 20 instances at one time.
Number of disableable commands	Each instance can disable up to 16 commands. You can set the disabled commands for an instance with the disabled-commands parameter, and multiple disabled commands are separated by a comma (,). For details, refer to Setting instance parameters.
Number of accounts available	Each Redis instance can have up to 100 accounts by default. If you need to create more accounts, please submit a ticket to contact technical support to modify relevant parameters.
Number of usable roles	Each Redis instance can have up to 100 roles by default. If you need to create more roles, please submit a ticket to contact technical support to modify relevant parameters.
Number of key parameters in a Lua script	For instances with proxy minor version less than 1.511.0, the maximum limit for the number of key parameters in a Lua script is 100 by default. When the number of keys exceeds the limit, an error message command arguments invalid will appear. If needed, submit a ticket to contact technical support to upgrade the instance proxy to the latest version and cancel this limit.

Last updated: 2026.07.31 11:59:29