ApsaraDB for Redis allows you to set custom instance parameters. This topic describes the parameters of different engine versions and the common methods to specify these parameters.

Precautions

Some parameters are not supported in earlier instance minor versions. If the current minor version is low, the following error may be prompted when you set these parameters. You must upgrade your instance to the latest minor version. For more information, see Upgrade the minor version.

Figure 1. Low minor version alert
Low minor version alert

Set parameters in the ApsaraDB for Redis console

  1. Log on to the ApsaraDB for Redis console.
  2. On the top of the page, select the region where the instance is deployed.
  3. On the Instance List page, click the Instance ID of the instance.
  4. In the left-side navigation pane, click System Parameters.
  5. On the System Parameters page, find the parameter that you want to modify and click Modify in the Actions column.Set parameters
  6. In the dialog box that appears, modify the parameter value and click OK. For more information about parameters and parameter values, see the following description based on the version of the Redis engine.
    Warning After you submit the modification for specific parameters, the instance is automatically restarted. The instance may be disconnected for a few seconds during the restart process. Modify parameters with caution. Before you modify a parameter, check the Restart and Take Effect column of the parameter to ensure that the instance does not need to restart for the modification to take effect.
  7. Click OK.

Parameter description

Different engine versions and architectures of ApsaraDB for Redis support different parameters. You can view the detailed description of parameters of specific engine versions by clicking the hyperlinks in the following table.

The ✔️ symbol in this topic indicates that the architecture supports the specific parameter. The ❌ symbol indicates that the architecture does not support the specific parameter.

Note To ensure the stability of ApsaraDB for Redis instances, you are allowed to set only a limited number of parameters. If a parameter is not described in this topic, you cannot modify the parameter.
Engine version Reference
Redis 5.0 Parameters supported by Redis 5.0
Redis 4.0 Parameters supported by Redis 4.0
Redis 2.8 Parameters supported by Redis 2.8

Parameters supported by Redis 5.0

Parameter Description Standard instance Cluster instance Read/write splitting instance
#no_loose_audit-read-enabled
Specifies whether to enable read request audit. After you enable this feature, you can view information about read requests in the audit log. Valid values:
  • yes: enables read request audit.
  • no: disables read request audit. This is the default value.
❌ ✔️ ✔️
#no_loose_check-whitelist-always
Specifies whether to verify that the client IP address is in a whitelist of the ApsaraDB for Redis instance if password-free access is enabled in a virtual private cloud (VPC). If you set this parameter to yes, the whitelist still takes effect for password-free access over a VPC. Valid values:
  • yes: enables the system to check whether a client IP address is in a whitelist.
  • no: disables the system to check whether a client IP address is in a whitelist. This is the default value.
✔️ ✔️ ✔️
#no_loose_disabled-commands
Specifies the commands to be disabled. You can disable high-risk commands or commands that have high time complexity, such as flushall, flushdb, keys, hgetall, eval, evalsha, and script.
Note The commands must be written in lowercase letters. Separate multiple commands with commas (,).
✔️ ✔️ ✔️
#no_loose_sentinel-enabled
Specifies whether to enable the Sentinel-compatible mode. Valid values:
  • yes: enables the Sentinel-compatible mode.
  • no: disables the Sentinel-compatible mode. This is the default value.
✔️ ✔️ ✔️
#no_loose_ssl-enabled
Specifies whether to enable secure sockets layer (SSL) encryption. Valid values:
  • yes: enables SSL encryption.
  • no: disables SSL encryption. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-cmds

Specifies whether to collect statistics about commands. By default, this parameter is empty. This indicates that no statistics are collected. Separate multiple commands with commas (,).

❌ ✔️ ✔️
#no_loose_statistics-ip-enable
Specifies whether to collect statistics about IP addresses. Valid values:
  • yes: enables to collect statistics about IP addresses.
  • no: disables to collect statistics about IP addresses. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-keys

Specifies whether to collect statistics about keys. By default, the value is empty. This indicates that no statistics are collected. Separate multiple keys with commas (,).

❌ ✔️ ✔️
#no_loose_tls-min-version
Specifies the minimum TLS version supported by the instance. Valid values:
  • TLSv1. This is the default value.
  • Tlsv1.1.
  • TLSv1.2.
❌ ✔️ ✔️
cluster_compat_enable
Specifies whether to enable support for Redis-native cluster syntax. Valid values:
  • 0: disables support for Redis-native cluster syntax.
  • 1: enables support for Redis-native cluster syntax. This is the default value.
❌ ✔️ ✔️
max_session_processing

Specifies the maximum number of pending requests that are allowed per connection. If a proxy node forwards requests from a client to a data node but does not receive a response from the data node, then the requests are pending. This parameter is used to prevent pending requests that are caused by capability difference between the frontend and backend of proxy nodes. This avoids an increase in memory usage.

❌ ✔️ ✔️
ptod_enabled
Specifies whether to forward client IP addresses to data nodes through the proxy node. Valid values:
  • 0: does not forward client IP addresses to data nodes. This is the default value.
  • 1: forwards client IP addresses to data nodes.
❌ ✔️ ✔️
readonly_lua_route_ronode_enable
Specifies whether to enable Lua scripting on read replicas. Valid values:
  • 0: disables Lua scripting. Read replicas do not support Lua scripts. The master node processes Lua scripts. This is the default value.
  • 1: enables Lua scripting. Lua scripts that include only read requests are forwarded to read replicas.
❌ ❌ ✔️
read_request_only_ronode_whenrwsplit_enable
Specifies whether to enable unidirectional forwarding for requests from accounts that have read-only permissions. Valid values:
  • 0: disables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to all nodes including the master node based on weights. This is the default value.
  • 1: enables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to only read replicas.
❌ ❌ ✔️
rt_threshold_ms
Specifies the threshold of slow query logs for a proxy node. Unit: milliseconds. If it takes longer than the threshold for the proxy node to process a request, the request is recorded in a slow query log.
Note This time starts when the proxy node sends a request to the data node and ends when the proxy node receives the response.
❌ ✔️ ✔️
script_check_enable
Specifies whether to check that the keys used in Lua scripts are mapped to the same slot. Valid values:
  • 0: does not check whether the keys are mapped to the same slot.
  • 1: checks whether the keys are mapped to the same slot. This is the default value.
❌ ✔️ ✔️
transfer_subscrible_to_psubscrible_enable
Specifies whether to enable the feature of converting SUBSCRIBE to PSUBSCRIBE. Valid values:
  • 0: disables this feature. The two commands cannot be converted. This is the default value.
  • 1: enables this feature. The proxy node can convert SUBSCRIBE to PSUBSCRIBE.
    Note If you use the PUB/SUB commands in Lua scripts, and the channel to which you have subscribed cannot receive messages, you can enable this feature to fix this issue.
❌ ✔️ ✔️
appendonly
Specifies whether to enable append-only file (AOF) persistence. Valid values:
  • yes: enables AOF persistence. This is the default value.
  • no: disables AOF persistence.
✔️ ✔️ ✔️
client-output-buffer-limit pubsub
Specifies output buffer limits of publisher and subscriber clients. The clients are disconnected when the specified limits are reached. Specify this parameter in the following format:<hard limit> <soft limit> <soft seconds>. Default value: 33554432 8388608 60.
  • <hard limit>: disconnects a client if the output buffer of the client is larger than or equal to the hard limit value. The hard limit value is measured in bytes.
  • <soft limit> and <soft seconds>: disconnects a client if the two conditions are met. One of the conditions is that the output buffer of the client is larger than or equal to the soft limit value. The other condition is that the situation lasts for a period longer than or equal to the soft seconds value. The soft limit value is measured in bytes. The soft seconds value is measured in seconds.
✔️ ✔️ ✔️
dynamic-hz
Specifies whether to enable a dynamic hz value. Valid values:
  • yes: enables a dynamic hz value. This is the default value.
  • no: disables a dynamic hz value.
✔️ ❌ ❌
hash-max-ziplist-entries
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hash-max-ziplist-value
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hz
Specifies how frequently tasks are performed in the background. For example, you can specify how frequently tasks are performed to evict expired keys. Valid values: 1 to 500. The default value is 10. The value specifies that each task is performed 10 times per second.
Note A higher value results in higher CPU consumption but allows the system to delete expired keys and close timeout connections more frequently. We recommend that you specify a value smaller than or equal to 100.
✔️ ✔️ ✔️
lazyfree-lazy-eviction
Specifies whether to enable the eviction feature based on the lazyfree mechanism. Valid values:
  • yes: enables the feature.
  • no: disables the feature. This is the default value.
✔️ ✔️ ✔️
lazyfree-lazy-expire
Specifies whether to delete expired keys based on the lazyfree mechanism. Valid values:
  • yes: enables the feature. This is the default value.
  • no: disables the feature.
✔️ ✔️ ✔️
lazyfree-lazy-server-del
Specifies whether to run the DEL command based on the lazyfree mechanism. Valid values:
  • yes: enables asynchronous deletion based on the lazyfree mechanism. This is the default value.
  • no: disables asynchronous deletion based on the lazyfree mechanism.
✔️ ✔️ ✔️
list-compress-depth
Specifies the number of entries that are not compressed at both ends in a list. Valid values: 0 to 65535.
  • 0: does not compress nodes of the list. This is the default value.
  • 1 to 65535: the specified number of nodes from each end of the list are not compressed, but all in-between nodes are compressed.
✔️ ✔️ ✔️
list-max-ziplist-size
  • Specifies the maximum size of each ziplist in a quicklist. A positive number indicates the maximum number of elements in each ziplist of a quicklist. For example, if you set this parameter to 5, each ziplist of a quicklist can contain a maximum of five elements.
  • A negative value indicates the maximum number of bytes in each ziplist of a quicklist.
    • -5: specifies that each ziplist of a quicklist cannot exceed 64 KB.
    • -4: specifies that each ziplist of a quicklist cannot exceed 32 KB.
    • -3: specifies that each ziplist of a quicklist cannot exceed 16 KB.
    • -2: specifies that each ziplist of a quicklist cannot exceed 8 KB. This is the default value.
    • -1: specifies that each ziplist of a quicklist cannot exceed 4 KB.
✔️ ✔️ ✔️
maxmemory-policy
Specifies the policy used to evict keys if the memory is exhausted. Valid values: LRU means least recently used. LFU means least frequently used. LRU, LFU, and TTL are implemented by using approximation and randomized algorithms.
  • volatile-lru: evicts the approximated least recently used (LRU) keys among keys that have time-to-live (TTL) values configured.
  • allkeys-lru: evicts the approximated LRU keys.
  • volatile-lfu: evicts the approximated least frequently used (LFU) keys among keys that have TTL values configured.
  • allkeys-lfu: evicts the approximated LFU keys.
  • volatile-random: evicts random keys among keys that have TTL values configured.
  • allkeys-random: randomly evicts keys.
  • volatile-ttl: evicts keys with an expire set, and evicts thoes that have a shorter TTL.
  • noeviction: specifies that the system does not evict keys, but returns an error for write operations.
✔️ ✔️ ✔️
notify-keyspace-events
The types of events of which the Redis server can notify clients. The value of this parameter is a combination of the following characters.
  • K: keyspace events. All notifications are published with a __keyspace@<db>__ prefix.
  • E: keyevent events. All notifications are published with a __keyevent@<db>__ prefix.
  • g: generic events that are not related to specific commands, such as DEL, EXPIRE, and RENAME.
  • $: events of string commands.
  • l: events of list commands.
  • s: events of set commands.
  • h: events of hash commands.
  • z: events of sorted set commands.
  • x: events of expired keys. An expiration event is triggered when an expired key is deleted.
  • e: eviction events. An eviction event is triggered when a key is evicted for maxmemory.
  • A: the alias for g$lshzxe.
Note The specified parameter must include at least K or E. Otherwise, no event is triggered.
✔️ ✔️ ✔️
set-max-intset-entries
The maximum number of data entries in a set to support intset encoding. A set uses intset encoding when both of the following conditions are met:
  • The number of entries in the set is smaller than or equal to the value of the set-max-intset-entries parameter.
  • The set contains only radix-10 integers in the range of 64-bit signed integers.
 ✔️ ✔️ ✔️
slowlog-log-slower-than

Specifies the threshold to log slow queries. You can set this parameter to log an operation when the execution duration of the operation exceeds the threshold in microseconds. Valid values: 10000 to 10000000. Default value: 20000.

✔️ ✔️ ✔️
slowlog-max-len

The maximum number of entries that can be stored in the slow query log. Valid values: 100 to 10000. Default value: 1024.

✔️ ✔️ ✔️
stream-node-max-bytes
The maximum amount of memory in bytes that each macro node in a stream can consume. Valid values: 0 to 999999999999999. Unit: bytes.
Note A value of 0 indicates that the number of entries on each node is unlimited.
✔️ ❌ ❌
stream-node-max-entries
The maximum number of entries stored on each macro node in a stream. Valid values: 0 to 999999999999999.
Note A value of 0 indicates that the number of entries on each node is unlimited.
✔️ ❌ ❌
timeout
Specifies a timeout period. The system closes a connection to a client if the connection has been idle for the specified period of time. Valid values: 0 to 100000. Unit: seconds.
Note A value of 0 specifies that no timeout period is specified for connections.
✔️ ✔️ ✔️
zset-max-ziplist-entries
Specifies the maximum number of key-value pairs stored in a sorted set. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the sorted set is smaller than the value of the zset-max-ziplist-value parameter.
  • The number of key-value pairs stored in the sorted set is smaller than the value of the zset-max-ziplist-entries parameter.
✔️ ✔️ ✔️
zset-max-ziplist-value ✔️ ✔️ ✔️

Parameters supported by Redis 4.0

Parameter Description Standard instance Cluster instance Read/write splitting instance
#no_loose_audit-read-enabled
Specifies whether to enable read request audit. After you enable this feature, you can view information about read requests in the audit log. Valid values:
  • yes: enables read request audit.
  • no: disables read request audit. This is the default value.
❌ ✔️ ✔️
#no_loose_check-whitelist-always
Specifies whether to verify that the client IP address is in a whitelist of the ApsaraDB for Redis instance if password-free access is enabled in a virtual private cloud (VPC). If you set this parameter to yes, the whitelist still takes effect for password-free access over a VPC. Valid values:
  • yes: enables the system to check whether a client IP address is in a whitelist.
  • no: disables the system to check whether a client IP address is in a whitelist. This is the default value.
✔️ ✔️ ✔️
#no_loose_disabled-commands
Specifies the commands to be disabled. You can disable high-risk commands or commands that have high time complexity, such as flushall, flushdb, keys, hgetall, eval, evalsha, and script.
Note The commands must be written in lowercase letters. Separate multiple commands with commas (,).
✔️ ✔️ ✔️
#no_loose_sentinel-enabled
Specifies whether to enable the Sentinel-compatible mode. Valid values:
  • yes: enables the Sentinel-compatible mode.
  • no: disables the Sentinel-compatible mode. This is the default value.
✔️ ✔️ ✔️
#no_loose_ssl-enabled
Specifies whether to enable secure sockets layer (SSL) encryption. Valid values:
  • yes: enables SSL encryption.
  • no: disables SSL encryption. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-cmds

Specifies whether to collect statistics about commands. By default, this parameter is empty. This indicates that no statistics are collected. Separate multiple commands with commas (,).

❌ ✔️ ✔️
#no_loose_statistics-ip-enable
Specifies whether to collect statistics about IP addresses. Valid values:
  • yes: enables to collect statistics about IP addresses.
  • no: disables to collect statistics about IP addresses. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-keys

Specifies whether to collect statistics about keys. By default, the value is empty. This indicates that no statistics are collected. Separate multiple keys with commas (,).

❌ ✔️ ✔️
#no_loose_tls-min-version
Specifies the minimum TLS version supported by the instance. Valid values:
  • TLSv1. This is the default value.
  • Tlsv1.1.
  • TLSv1.2.
❌ ✔️ ✔️
cluster_compat_enable
Specifies whether to enable support for Redis-native cluster syntax. Valid values:
  • 0: disables support for Redis-native cluster syntax.
  • 1: enables support for Redis-native cluster syntax. This is the default value.
❌ ✔️ ✔️
max_session_processing

Specifies the maximum number of pending requests that are allowed per connection. If a proxy node forwards requests from a client to a data node but does not receive a response from the data node, then the requests are pending. This parameter is used to prevent pending requests that are caused by capability difference between the frontend and backend of proxy nodes. This avoids an increase in memory usage.

❌ ✔️ ✔️
ptod_enabled
Specifies whether to forward client IP addresses to data nodes through the proxy node. Valid values:
  • 0: does not forward client IP addresses to data nodes. This is the default value.
  • 1: forwards client IP addresses to data nodes.
❌ ✔️ ✔️
readonly_lua_route_ronode_enable
Specifies whether to enable Lua scripting on read replicas. Valid values:
  • 0: disables Lua scripting. Read replicas do not support Lua scripts. The master node processes Lua scripts. This is the default value.
  • 1: enables Lua scripting. Lua scripts that include only read requests are forwarded to read replicas.
❌ ❌ ✔️
read_request_only_ronode_whenrwsplit_enable
Specifies whether to enable unidirectional forwarding for requests from accounts that have read-only permissions. Valid values:
  • 0: disables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to all nodes including the master node based on weights. This is the default value.
  • 1: enables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to only read replicas.
❌ ❌ ✔️
rt_threshold_ms
Specifies the threshold of slow query logs for a proxy node. Unit: milliseconds. If it takes longer than the threshold for the proxy node to process a request, the request is recorded in a slow query log.
Note This time starts when the proxy node sends a request to the data node and ends when the proxy node receives the response.
❌ ✔️ ✔️
script_check_enable
Specifies whether to check that the keys used in Lua scripts are mapped to the same slot. Valid values:
  • 0: does not check whether the keys are mapped to the same slot.
  • 1: checks whether the keys are mapped to the same slot. This is the default value.
❌ ✔️ ✔️
transfer_subscrible_to_psubscrible_enable
Specifies whether to enable the feature of converting SUBSCRIBE to PSUBSCRIBE. Valid values:
  • 0: disables this feature. The two commands cannot be converted. This is the default value.
  • 1: enables this feature. The proxy node can convert SUBSCRIBE to PSUBSCRIBE.
    Note If you use the PUB/SUB commands in Lua scripts, and the channel to which you have subscribed cannot receive messages, you can enable this feature to fix this issue.
❌ ✔️ ✔️
appendonly
Specifies whether to enable append-only file (AOF) persistence. Valid values:
  • yes: enables AOF persistence. This is the default value.
  • no: disables AOF persistence.
✔️ ✔️ ✔️
client-output-buffer-limit pubsub
Specifies output buffer limits of publisher and subscriber clients. The clients are disconnected when the specified limits are reached. Specify this parameter in the following format:<hard limit> <soft limit> <soft seconds>. Default value: 33554432 8388608 60.
  • <hard limit>: disconnects a client if the output buffer of the client is larger than or equal to the hard limit value. The hard limit value is measured in bytes.
  • <soft limit> and <soft seconds>: disconnects a client if the two conditions are met. One of the conditions is that the output buffer of the client is larger than or equal to the soft limit value. The other condition is that the situation lasts for a period longer than or equal to the soft seconds value. The soft limit value is measured in bytes. The soft seconds value is measured in seconds.
✔️ ✔️ ✔️
hash-max-ziplist-entries
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hash-max-ziplist-value
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hz
Specifies how frequently tasks are performed in the background. For example, you can specify how frequently tasks are performed to evict expired keys. Valid values: 1 to 500. The default value is 10. The value specifies that each task is performed 10 times per second.
Note A higher value results in higher CPU consumption but allows the system to delete expired keys and close timeout connections more frequently. We recommend that you specify a value smaller than or equal to 100.
✔️ ✔️ ✔️
lazyfree-lazy-eviction
Specifies whether to enable the eviction feature based on the lazyfree mechanism. Valid values:
  • yes: enables the feature.
  • no: disables the feature. This is the default value.
✔️ ✔️ ✔️
lazyfree-lazy-expire
Specifies whether to delete expired keys based on the lazyfree mechanism. Valid values:
  • yes: enables the feature. This is the default value.
  • no: disables the feature.
✔️ ✔️ ✔️
lazyfree-lazy-server-del
Specifies whether to run the DEL command based on the lazyfree mechanism. Valid values:
  • yes: enables asynchronous deletion based on the lazyfree mechanism. This is the default value.
  • no: disables asynchronous deletion based on the lazyfree mechanism.
✔️ ✔️ ✔️
list-compress-depth
Specifies the number of entries that are not compressed at both ends in a list. Valid values: 0 to 65535.
  • 0: does not compress nodes of the list. This is the default value.
  • 1 to 65535: the specified number of nodes from each end of the list are not compressed, but all in-between nodes are compressed.
✔️ ✔️ ✔️
list-max-ziplist-size
  • Specifies the maximum size of each ziplist in a quicklist. A positive number indicates the maximum number of elements in each ziplist of a quicklist. For example, if you set this parameter to 5, each ziplist of a quicklist can contain a maximum of five elements.
  • A negative value indicates the maximum number of bytes in each ziplist of a quicklist.
    • -5: specifies that each ziplist of a quicklist cannot exceed 64 KB.
    • -4: specifies that each ziplist of a quicklist cannot exceed 32 KB.
    • -3: specifies that each ziplist of a quicklist cannot exceed 16 KB.
    • -2: specifies that each ziplist of a quicklist cannot exceed 8 KB. This is the default value.
    • -1: specifies that each ziplist of a quicklist cannot exceed 4 KB.
✔️ ✔️ ✔️
maxmemory-policy
Specifies the policy used to evict keys if the memory is exhausted. Valid values: LRU means least recently used. LFU means least frequently used. LRU, LFU, and TTL are implemented by using approximation and randomized algorithms.
  • volatile-lru: evicts the approximated least recently used (LRU) keys among keys that have time-to-live (TTL) values configured.
  • allkeys-lru: evicts the approximated LRU keys.
  • volatile-lfu: evicts the approximated least frequently used (LFU) keys among keys that have TTL values configured.
  • allkeys-lfu: evicts the approximated LFU keys.
  • volatile-random: evicts random keys among keys that have TTL values configured.
  • allkeys-random: randomly evicts keys.
  • volatile-ttl: evicts keys with an expire set, and evicts thoes that have a shorter TTL.
  • noeviction: specifies that the system does not evict keys, but returns an error for write operations.
✔️ ✔️ ✔️
notify-keyspace-events
The types of events of which the Redis server can notify clients. The value of this parameter is a combination of the following characters.
  • K: keyspace events. All notifications are published with a __keyspace@<db>__ prefix.
  • E: keyevent events. All notifications are published with a __keyevent@<db>__ prefix.
  • g: generic events that are not related to specific commands, such as DEL, EXPIRE, and RENAME.
  • $: events of string commands.
  • l: events of list commands.
  • s: events of set commands.
  • h: events of hash commands.
  • z: events of sorted set commands.
  • x: events of expired keys. An expiration event is triggered when an expired key is deleted.
  • e: eviction events. An eviction event is triggered when a key is evicted for maxmemory.
  • A: the alias for g$lshzxe.
Note The specified parameter must include at least K or E. Otherwise, no event is triggered.
✔️ ✔️ ✔️
set-max-intset-entries
The maximum number of data entries in a set to support intset encoding. A set uses intset encoding when both of the following conditions are met:
  • The number of entries in the set is smaller than or equal to the value of the set-max-intset-entries parameter.
  • The set contains only radix-10 integers in the range of 64-bit signed integers.
 ✔️ ✔️ ✔️
slowlog-log-slower-than

Specifies the threshold to log slow queries. You can set this parameter to log an operation when the execution duration of the operation exceeds the threshold in microseconds. Valid values: 10000 to 10000000. Default value: 20000.

✔️ ✔️ ✔️
slowlog-max-len

The maximum number of entries that can be stored in the slow query log. Valid values: 100 to 10000. Default value: 1024.

✔️ ✔️ ✔️
timeout
Specifies a timeout period. The system closes a connection to a client if the connection has been idle for the specified period of time. Valid values: 0 to 100000. Unit: seconds.
Note A value of 0 specifies that no timeout period is specified for connections.
✔️ ✔️ ✔️
zset-max-ziplist-entries
Specifies the maximum number of key-value pairs stored in a sorted set. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the sorted set is smaller than the value of the zset-max-ziplist-value parameter.
  • The number of key-value pairs stored in the sorted set is smaller than the value of the zset-max-ziplist-entries parameter.
✔️ ✔️ ✔️
zset-max-ziplist-value ✔️ ✔️ ✔️

Parameters supported by Redis 2.8

Parameter Description Standard instance Cluster instance Read/write splitting instance
#no_loose_audit-read-enabled
Specifies whether to enable read request audit. After you enable this feature, you can view information about read requests in the audit log. Valid values:
  • yes: enables read request audit.
  • no: disables read request audit. This is the default value.
❌ ✔️ ✔️
#no_loose_disabled-commands
Specifies the commands to be disabled. You can disable high-risk commands or commands that have high time complexity, such as flushall, flushdb, keys, hgetall, eval, evalsha, and script.
Note The commands must be written in lowercase letters. Separate multiple commands with commas (,).
✔️ ✔️ ✔️
#no_loose_ssl-enabled
Specifies whether to enable secure sockets layer (SSL) encryption. Valid values:
  • yes: enables SSL encryption.
  • no: disables SSL encryption. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-cmds

Specifies whether to collect statistics about commands. By default, this parameter is empty. This indicates that no statistics are collected. Separate multiple commands with commas (,).

❌ ✔️ ✔️
#no_loose_statistics-ip-enable
Specifies whether to collect statistics about IP addresses. Valid values:
  • yes: enables to collect statistics about IP addresses.
  • no: disables to collect statistics about IP addresses. This is the default value.
❌ ✔️ ✔️
#no_loose_statistics-keys

Specifies whether to collect statistics about keys. By default, the value is empty. This indicates that no statistics are collected. Separate multiple keys with commas (,).

❌ ✔️ ✔️
#no_loose_tls-min-version
Specifies the minimum TLS version supported by the instance. Valid values:
  • TLSv1. This is the default value.
  • Tlsv1.1.
  • TLSv1.2.
❌ ✔️ ✔️
cluster_compat_enable
Specifies whether to enable support for Redis-native cluster syntax. Valid values:
  • 0: disables support for Redis-native cluster syntax.
  • 1: enables support for Redis-native cluster syntax. This is the default value.
❌ ✔️ ✔️
max_session_processing

Specifies the maximum number of pending requests that are allowed per connection. If a proxy node forwards requests from a client to a data node but does not receive a response from the data node, then the requests are pending. This parameter is used to prevent pending requests that are caused by capability difference between the frontend and backend of proxy nodes. This avoids an increase in memory usage.

❌ ✔️ ✔️
read_request_only_ronode_whenrwsplit_enable
Specifies whether to enable unidirectional forwarding for requests from accounts that have read-only permissions. Valid values:
  • 0: disables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to all nodes including the master node based on weights. This is the default value.
  • 1: enables unidirectional forwarding. Requests from accounts that have read-only permissions are forwarded to only read replicas.
❌ ❌ ✔️
rt_threshold_ms
Specifies the threshold of slow query logs for a proxy node. Unit: milliseconds. If it takes longer than the threshold for the proxy node to process a request, the request is recorded in a slow query log.
Note This time starts when the proxy node sends a request to the data node and ends when the proxy node receives the response.
❌ ✔️ ✔️
script_check_enable
Specifies whether to check that the keys used in Lua scripts are mapped to the same slot. Valid values:
  • 0: does not check whether the keys are mapped to the same slot.
  • 1: checks whether the keys are mapped to the same slot. This is the default value.
❌ ✔️ ✔️
appendonly
Specifies whether to enable append-only file (AOF) persistence. Valid values:
  • yes: enables AOF persistence. This is the default value.
  • no: disables AOF persistence.
✔️ ✔️ ✔️
client-output-buffer-limit pubsub
Specifies output buffer limits of publisher and subscriber clients. The clients are disconnected when the specified limits are reached. Specify this parameter in the following format:<hard limit> <soft limit> <soft seconds>. Default value: 33554432 8388608 60.
  • <hard limit>: disconnects a client if the output buffer of the client is larger than or equal to the hard limit value. The hard limit value is measured in bytes.
  • <soft limit> and <soft seconds>: disconnects a client if the two conditions are met. One of the conditions is that the output buffer of the client is larger than or equal to the soft limit value. The other condition is that the situation lasts for a period longer than or equal to the soft seconds value. The soft limit value is measured in bytes. The soft seconds value is measured in seconds.
✔️ ✔️ ✔️
hash-max-ziplist-entries
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hash-max-ziplist-value
Specifies the maximum number of bytes of the key or value in each key-value pair stored in a hash. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the hash is smaller than the value of the hash-max-ziplist-value parameter.
  • The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.
✔️ ✔️ ✔️
hz
Specifies how frequently tasks are performed in the background. For example, you can specify how frequently tasks are performed to evict expired keys. Valid values: 1 to 500. The default value is 10. The value specifies that each task is performed 10 times per second.
Note A higher value results in higher CPU consumption but allows the system to delete expired keys and close timeout connections more frequently. We recommend that you specify a value smaller than or equal to 100.
✔️ ✔️ ✔️
list-max-ziplist-entries

Specifies the maximum number of bytes of the key or value in each key-value pair stored in a list. The ziplist encoding is used only if both of the following conditions are met:

  • The number of bytes in each element stored in the list is smaller than the value of the list-max-ziplist-value parameter.
  • The number of elements stored in the list is smaller than the value of the list-max-ziplist-entries parameter.
✔️ ✔️ ✔️
list-max-ziplist-value

Specifies the maximum number of bytes of the key or value in each key-value pair stored in a list. The ziplist encoding is used only if both of the following conditions are met:

  • The number of bytes in each element stored in the list is smaller than the value of the list-max-ziplist-value parameter.
  • The number of elements stored in the list is smaller than the value of the list-max-ziplist-entries parameter.
✔️ ✔️ ✔️
maxmemory-policy
Specifies the policy used to evict keys if the memory is exhausted. Valid values: LRU means least recently used. LFU means least frequently used. LRU, LFU, and TTL are implemented by using approximation and randomized algorithms.
  • volatile-lru: evicts the approximated least recently used (LRU) keys among keys that have time-to-live (TTL) values configured.
  • allkeys-lru: evicts the approximated LRU keys.
  • volatile-lfu: evicts the approximated least frequently used (LFU) keys among keys that have TTL values configured.
  • allkeys-lfu: evicts the approximated LFU keys.
  • volatile-random: evicts random keys among keys that have TTL values configured.
  • allkeys-random: randomly evicts keys.
  • volatile-ttl: evicts keys with an expire set, and evicts thoes that have a shorter TTL.
  • noeviction: specifies that the system does not evict keys, but returns an error for write operations.
✔️ ✔️ ✔️
notify-keyspace-events
The types of events of which the Redis server can notify clients. The value of this parameter is a combination of the following characters.
  • K: keyspace events. All notifications are published with a __keyspace@<db>__ prefix.
  • E: keyevent events. All notifications are published with a __keyevent@<db>__ prefix.
  • g: generic events that are not related to specific commands, such as DEL, EXPIRE, and RENAME.
  • $: events of string commands.
  • l: events of list commands.
  • s: events of set commands.
  • h: events of hash commands.
  • z: events of sorted set commands.
  • x: events of expired keys. An expiration event is triggered when an expired key is deleted.
  • e: eviction events. An eviction event is triggered when a key is evicted for maxmemory.
  • A: the alias for g$lshzxe.
Note The specified parameter must include at least K or E. Otherwise, no event is triggered.
✔️ ✔️ ✔️
set-max-intset-entries
The maximum number of data entries in a set to support intset encoding. A set uses intset encoding when both of the following conditions are met:
  • The number of entries in the set is smaller than or equal to the value of the set-max-intset-entries parameter.
  • The set contains only radix-10 integers in the range of 64-bit signed integers.
 ✔️ ✔️ ✔️
slowlog-log-slower-than

Specifies the threshold to log slow queries. You can set this parameter to log an operation when the execution duration of the operation exceeds the threshold in microseconds. Valid values: 10000 to 10000000. Default value: 20000.

✔️ ✔️ ✔️
slowlog-max-len

The maximum number of entries that can be stored in the slow query log. Valid values: 100 to 10000. Default value: 1024.

✔️ ✔️ ✔️
zset-max-ziplist-entries
Specifies the maximum number of key-value pairs stored in a sorted set. The ziplist encoding is used only if both of the following conditions are met:
  • The number of bytes of the key or value in each key-value pair stored in the sorted set is smaller than the value of the zset-max-ziplist-value parameter.
  • The number of key-value pairs stored in the sorted set is smaller than the value of the zset-max-ziplist-entries parameter.
✔️ ✔️ ✔️
zset-max-ziplist-value ✔️ ✔️ ✔️