Configurable Parameter List

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Configurable Parameter List

Last updated: 2024-09-23 09:51:00

Parameter
Description
Supported Versions
auto-failback
For instances deployed in multiple availability zones, this parameter specifies whether the primary node will automatically switch back to the primary node group (Cluster) after failure recovery.
Redis 4.0, 5.0, and 6.2
disable-command-list
Sets disabled commands. Users can disable certain commands that have high time complexity or pose high risk, based on business needs. Disabled commands will not be allowed to run on the instance. Multiple commands can be configured, e.g., flushdb, keys.
Redis 2.8, 4.0, 5.0, and 6.2

hz
Sets the execution frequency.
Redis 2.8, 4.0, 5.0, and 6.2
maxmemory-policy
Sets the eviction policy for Redis when memory is full. The following policies can be selected:
volatile-lru: Evicts keys with TTL set using the LRU algorithm, prioritizing the least recently used keys that have an expiration time.
allkeys-lru: Evicts all keys using the LRU algorithm, regardless of whether they have a timeout attribute, prioritizing the least recently used keys until enough space is freed.
volatile-random: Randomly evicts keys with TTL set.
allkeys-random: Randomly evicts all keys.
volatile-ttl: Prioritizes evicting keys with the smallest TTL value among those with TTL set.
noeviction: Does not evict any keys. Write operations are rejected, and an error is returned for write attempts.
volatile-lfu: Prioritizes evicting the least frequently used (LFU) keys among those with TTL set.
allkeys-lfu: Prioritizes evicting the LFU keys from all keys, not just those with TTL set, unlike the volatile-lfu policy.
LRU (Least Recently Used) refers to the least recently used, TTL (Time To Live) refers to the setting of expiration times, and LFU (Least Frequently Used) refers to the least frequently used. For more information, see User Guide.
Redis 2.8, 4.0, 5.0, and 6.2
Memcached Edition 1.6
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UserPasswordSeparate
Specifies the password delimiter for custom accounts.
Note:
If the current running parameter value indicates that the current proxy version does not support modifying the UserPasswordSeparate parameter, follow the prompts on the interface to upgrade the proxy version.
Redis 4.0, 5.0, and 6.2
cluster-node-timeout
Sets the cluster node timeout, which is the amount of time (in milliseconds) that a node should be unreachable in the cluster before being considered in a failure status.
Redis 4.0, 5.0, and 6.2
rehash-maintenance-time
Sets whether to allow rehash operations during the maintenance time window.
Note:
If the interface indicates that the Redis minor version does not support modifying the rehash-maintenance-time parameter, upgrade the minor version.
no: The default value, indicating this feature is disabled, and Redis uses the native rehash scheme, where rehash is triggered when the load factor reaches a preset threshold.
yes: Enables Tencent's self-developed enhanced rehash feature to minimize or reduce performance fluctuations during Redis operations.
When the load factor of the hash table is less than 1.618, progressive rehashing is performed during the maintenance time window to avoid performance impacts.
When the load factor of the hash table exceeds 1.618, the system automatically triggers full rehash to ensure the efficiency and stability of the data structure.
Redis 4.0, 5.0, and 6.2
hash-max-ziplist-entries
When a hash object meets the following two conditions, it uses ziplist encoding:
The length in bytes of all key-value pairs (both key and value) stored in the hash object is less than the value of hash-max-ziplist-value.
The number of key-value pairs stored in the hash object is less than the value of hash-max-ziplist-entries.
Redis 2.8, 4.0, 5.0, and 6.2
hash-max-ziplist-value
When a hash object meets the following two conditions, it uses ziplist encoding:
The length in bytes of all key-value pairs (both key and value) stored in the hash object is less than the value of hash-max-ziplist-value.
The number of key-value pairs stored in the hash object is less than the value of hash-max-ziplist-entries.
Redis 2.8, 4.0, 5.0, and 6.2

lazyfree-lazy-eviction
This parameter controls whether Redis uses Lazy Free and Lazy Eviction during memory reclamation.
Lazy Free: When Redis needs to delete a key-value pair, it does not immediately delete it from memory. Instead, the key-value pair is marked as to be deleted, and it will be deleted upon the next access. It is added to the expiration queue and cleared based on the frequency set by HZ.
Lazy Eviction: When Redis needs to release memory, it does not immediately release it. Instead, some key-value pairs are marked as to be released and added to the expiration queue, and expired keys will be cleared based on the frequency set by HZ. This reduces memory cleanup overhead, but can lead to higher memory usage.
The values for this parameter are as follows:
no: Indicates that Lazy Free and Lazy Eviction are not used. Redis immediately deletes key-value pairs or releases memory during memory reclamation.
yes: Indicates that Lazy Free and Lazy Eviction are used.
Redis 2.8, 4.0, 5.0, and 6.2

lazyfree-lazy-expire
This parameter is used to control whether Redis performs Lazy Free when performing Expiration Key Deletion.
no: Indicates that Lazy Free is not used. Redis immediately deletes key-value pairs when performing Expiration Key Deletion.
yes: Indicates that Lazy Free is used. Redis marks some key-value pairs as to be deleted and adds them to the expiration queue when performing Expiration Key Deletion. These expired keys will be cleared based on the frequency set by HZ.
Redis 4.0, 5.0, and 6.2

lazyfree-lazy-server-del
This parameter controls Lazy Free behavior when Redis executes the DEL command to delete key-value pairs.
no: Indicates that Lazy Free is not used. Redis immediately deletes key-value pairs when the DEL command is executed.
yes: Indicates that Lazy Free is used. Redis marks some key-value pairs as to be deleted and adds them to the expiration queue. These expired keys will be cleared based on the frequency set by HZ.
Redis 4.0, 5.0, and 6.2

lazyfree-lazy-user-del
This parameter specifies whether the default behavior of the DEL command should be the same as that of the UNLINK command. The DEL command deletes one or more key-value pairs in Redis, while the UNLINK command performs Lazy Free before the key-value pairs are deleted.
no: The DEL command will immediately delete the key-value pairs from memory without performing Lazy Free.
yes: The default behavior of the DEL command will be the same as that of the UNLINK command, performing Lazy Free before deleting the key-value pairs from memory when the DEL command is executed.
Redis 4.0, 5.0, and 6.2
proxy-slowlog-log-slower-than
Sets the threshold for logging slow operations in Proxy. This specifies the minimum execution time (in milliseconds) for an operation to be recorded in the Proxy slow log.
Redis 2.8, 4.0, 5.0, and 6.2
Memcached Edition 1.6

read-local-node-only
This parameter specifies whether to enable or disable local node access when instances are deployed in multiple availability zones.
Redis 4.0 and 5.0
sentineauth
This parameter controls whether the Redis password is omitted when the sentinel command is used to interact with Redis Sentinel, automatically using the password specified by the sentinelauth parameter in the Sentinel configuration file.
6.2
set-max-intset-entries
When a set object meets the following two conditions, it uses intset encoding:
All data in the set object are strings.
They are all base-10 integers within the range of 64-bit signed integers.
Redis 2.8, 4.0, and 5.0
slowlog-log-slower-than
Sets the threshold for slow log, specifying the minimum execution time (in milliseconds) for operations to be recorded in the slow log.
Redis 2.8, 4.0, and 5.0
timeout
Specifies the idle time (in seconds) after which the client connection will be closed.
Redis 2.8, 4.0, and 5.0
zset-max-ziplist-entries
When a sorted set object meets the following two conditions, it uses ziplist encoding:
The length in bytes of each element's string in the sorted set object is less than the value specified by zset-max-ziplist-value.
The number of elements is less than the value specified by zset-max-ziplist-entries.
Redis 2.8, 4.0, and 5.0
zset-max-ziplist-value
When a sorted set object meets the following two conditions, it uses ziplist encoding:
The length in bytes of each element's string in the sorted set object is less than the value specified by zset-max-ziplist-value.
The number of elements is less than the value specified by zset-max-ziplist-entries.
Redis 2.8, 4.0, and 5.0
notify-keyspace-events
The parameter notify-keyspace-events is a combination of the following characters that defines which types of notifications the server will send.
Characters and their corresponding notifications:
K: Keyspace notifications, with all notifications prefixed by __keyspace@<db>__
E: Key event notifications, with all notifications prefixed by __keyevent@<db>__
g: Generic notifications for commands like DEL, EXPIRE, RENAME
$: Notifications for string commands
l: Notifications for list commands
s: Notifications for set commands
h: Notifications for hash commands
z: Notifications for sorted set commands
x: Expiration event notifications, sent when an expired key is deleted
e: Eviction event notifications, sent when a key is deleted due to the maxmemory policy
A: Alias for g$lshzxe, representing all the generic notifications. Enabling keyspace notifications consumes CPU resources, so they are disabled by default. To enable notifications, the parameter should include K or E. For example, to subscribe to eviction-related events, set the parameter to Ee. To subscribe to all types of notifications, set the parameter to AKE.
Redis 2.8, 4.0, and 5.0
list-max-ziplist-entries
When a list object meets the following two conditions, it uses ziplist encoding:
The length in bytes of each element's string in the list is less than the value specified by list-max-ziplist-value.
The number of elements is less than the value specified by list-max-ziplist-entries.
Redis 2.8
list-max-ziplist-value
When a list object meets the following two conditions, it uses ziplist encoding:
The length in bytes of each element's string in the list is less than the value specified by list-max-ziplist-value.
The number of elements is less than the value specified by list-max-ziplist-entries.
Redis 2.8
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Configurable Parameter List

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Parameter	Description	Supported Versions
auto-failback	For instances deployed in multiple availability zones, this parameter specifies whether the primary node will automatically switch back to the primary node group (Cluster) after failure recovery.	Redis 4.0, 5.0, and 6.2
disable-command-list	Sets disabled commands. Users can disable certain commands that have high time complexity or pose high risk, based on business needs. Disabled commands will not be allowed to run on the instance. Multiple commands can be configured, e.g., flushdb, keys.	Redis 2.8, 4.0, 5.0, and 6.2
hz	Sets the execution frequency.	Redis 2.8, 4.0, 5.0, and 6.2
maxmemory-policy	Sets the eviction policy for Redis when memory is full. The following policies can be selected: volatile-lru: Evicts keys with TTL set using the LRU algorithm, prioritizing the least recently used keys that have an expiration time. allkeys-lru: Evicts all keys using the LRU algorithm, regardless of whether they have a timeout attribute, prioritizing the least recently used keys until enough space is freed. volatile-random: Randomly evicts keys with TTL set. allkeys-random: Randomly evicts all keys. volatile-ttl: Prioritizes evicting keys with the smallest TTL value among those with TTL set. noeviction: Does not evict any keys. Write operations are rejected, and an error is returned for write attempts. volatile-lfu: Prioritizes evicting the least frequently used (LFU) keys among those with TTL set. allkeys-lfu: Prioritizes evicting the LFU keys from all keys, not just those with TTL set, unlike the volatile-lfu policy. LRU (Least Recently Used) refers to the least recently used, TTL (Time To Live) refers to the setting of expiration times, and LFU (Least Frequently Used) refers to the least frequently used. For more information, see User Guide.	Redis 2.8, 4.0, 5.0, and 6.2 Memcached Edition 1.6
UserPasswordSeparate	Specifies the password delimiter for custom accounts. Note: If the current running parameter value indicates that the current proxy version does not support modifying the UserPasswordSeparate parameter, follow the prompts on the interface to upgrade the proxy version.	Redis 4.0, 5.0, and 6.2
cluster-node-timeout	Sets the cluster node timeout, which is the amount of time (in milliseconds) that a node should be unreachable in the cluster before being considered in a failure status.	Redis 4.0, 5.0, and 6.2
rehash-maintenance-time	Sets whether to allow rehash operations during the maintenance time window. Note: If the interface indicates that the Redis minor version does not support modifying the rehash-maintenance-time parameter, upgrade the minor version. no: The default value, indicating this feature is disabled, and Redis uses the native rehash scheme, where rehash is triggered when the load factor reaches a preset threshold. yes: Enables Tencent's self-developed enhanced rehash feature to minimize or reduce performance fluctuations during Redis operations. When the load factor of the hash table is less than 1.618, progressive rehashing is performed during the maintenance time window to avoid performance impacts. When the load factor of the hash table exceeds 1.618, the system automatically triggers full rehash to ensure the efficiency and stability of the data structure.	Redis 4.0, 5.0, and 6.2
hash-max-ziplist-entries	When a hash object meets the following two conditions, it uses ziplist encoding: The length in bytes of all key-value pairs (both key and value) stored in the hash object is less than the value of `hash-max-ziplist-value`. The number of key-value pairs stored in the hash object is less than the value of `hash-max-ziplist-entries`.	Redis 2.8, 4.0, 5.0, and 6.2
hash-max-ziplist-value	When a hash object meets the following two conditions, it uses ziplist encoding: The length in bytes of all key-value pairs (both key and value) stored in the hash object is less than the value of `hash-max-ziplist-value`. The number of key-value pairs stored in the hash object is less than the value of `hash-max-ziplist-entries`.	Redis 2.8, 4.0, 5.0, and 6.2
lazyfree-lazy-eviction	This parameter controls whether Redis uses Lazy Free and Lazy Eviction during memory reclamation. Lazy Free: When Redis needs to delete a key-value pair, it does not immediately delete it from memory. Instead, the key-value pair is marked as to be deleted, and it will be deleted upon the next access. It is added to the expiration queue and cleared based on the frequency set by HZ. Lazy Eviction: When Redis needs to release memory, it does not immediately release it. Instead, some key-value pairs are marked as to be released and added to the expiration queue, and expired keys will be cleared based on the frequency set by HZ. This reduces memory cleanup overhead, but can lead to higher memory usage. The values for this parameter are as follows: no: Indicates that Lazy Free and Lazy Eviction are not used. Redis immediately deletes key-value pairs or releases memory during memory reclamation. yes: Indicates that Lazy Free and Lazy Eviction are used.	Redis 2.8, 4.0, 5.0, and 6.2
lazyfree-lazy-expire	This parameter is used to control whether Redis performs Lazy Free when performing Expiration Key Deletion. no: Indicates that Lazy Free is not used. Redis immediately deletes key-value pairs when performing Expiration Key Deletion. yes: Indicates that Lazy Free is used. Redis marks some key-value pairs as to be deleted and adds them to the expiration queue when performing Expiration Key Deletion. These expired keys will be cleared based on the frequency set by HZ.	Redis 4.0, 5.0, and 6.2
lazyfree-lazy-server-del	This parameter controls Lazy Free behavior when Redis executes the DEL command to delete key-value pairs. no: Indicates that Lazy Free is not used. Redis immediately deletes key-value pairs when the DEL command is executed. yes: Indicates that Lazy Free is used. Redis marks some key-value pairs as to be deleted and adds them to the expiration queue. These expired keys will be cleared based on the frequency set by HZ.	Redis 4.0, 5.0, and 6.2
lazyfree-lazy-user-del	This parameter specifies whether the default behavior of the DEL command should be the same as that of the UNLINK command. The DEL command deletes one or more key-value pairs in Redis, while the UNLINK command performs Lazy Free before the key-value pairs are deleted. no: The DEL command will immediately delete the key-value pairs from memory without performing Lazy Free. yes: The default behavior of the DEL command will be the same as that of the UNLINK command, performing Lazy Free before deleting the key-value pairs from memory when the DEL command is executed.	Redis 4.0, 5.0, and 6.2
proxy-slowlog-log-slower-than	Sets the threshold for logging slow operations in Proxy. This specifies the minimum execution time (in milliseconds) for an operation to be recorded in the Proxy slow log.	Redis 2.8, 4.0, 5.0, and 6.2 Memcached Edition 1.6
read-local-node-only	This parameter specifies whether to enable or disable local node access when instances are deployed in multiple availability zones.	Redis 4.0 and 5.0
sentineauth	This parameter controls whether the Redis password is omitted when the sentinel command is used to interact with Redis Sentinel, automatically using the password specified by the sentinelauth parameter in the Sentinel configuration file.	6.2
set-max-intset-entries	When a set object meets the following two conditions, it uses intset encoding: All data in the set object are strings. They are all base-10 integers within the range of 64-bit signed integers.	Redis 2.8, 4.0, and 5.0
slowlog-log-slower-than	Sets the threshold for slow log, specifying the minimum execution time (in milliseconds) for operations to be recorded in the slow log.	Redis 2.8, 4.0, and 5.0
timeout	Specifies the idle time (in seconds) after which the client connection will be closed.	Redis 2.8, 4.0, and 5.0
zset-max-ziplist-entries	When a sorted set object meets the following two conditions, it uses ziplist encoding: The length in bytes of each element's string in the sorted set object is less than the value specified by `zset-max-ziplist-value`. The number of elements is less than the value specified by `zset-max-ziplist-entries`.	Redis 2.8, 4.0, and 5.0
zset-max-ziplist-value	When a sorted set object meets the following two conditions, it uses ziplist encoding: The length in bytes of each element's string in the sorted set object is less than the value specified by `zset-max-ziplist-value`. The number of elements is less than the value specified by `zset-max-ziplist-entries`.	Redis 2.8, 4.0, and 5.0
notify-keyspace-events	The parameter `notify-keyspace-events` is a combination of the following characters that defines which types of notifications the server will send. Characters and their corresponding notifications: K: Keyspace notifications, with all notifications prefixed by `__keyspace@<db>__` E: Key event notifications, with all notifications prefixed by `__keyevent@<db>__` g: Generic notifications for commands like DEL, EXPIRE, RENAME $: Notifications for string commands l: Notifications for list commands s: Notifications for set commands h: Notifications for hash commands z: Notifications for sorted set commands x: Expiration event notifications, sent when an expired key is deleted e: Eviction event notifications, sent when a key is deleted due to the maxmemory policy A: Alias for g$lshzxe, representing all the generic notifications. Enabling keyspace notifications consumes CPU resources, so they are disabled by default. To enable notifications, the parameter should include K or E. For example, to subscribe to eviction-related events, set the parameter to Ee. To subscribe to all types of notifications, set the parameter to AKE.	Redis 2.8, 4.0, and 5.0
list-max-ziplist-entries	When a list object meets the following two conditions, it uses ziplist encoding: The length in bytes of each element's string in the list is less than the value specified by `list-max-ziplist-value`. The number of elements is less than the value specified by `list-max-ziplist-entries`.	Redis 2.8
list-max-ziplist-value	When a list object meets the following two conditions, it uses ziplist encoding: The length in bytes of each element's string in the list is less than the value specified by `list-max-ziplist-value`. The number of elements is less than the value specified by `list-max-ziplist-entries`.	Redis 2.8

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