Tair (Redis® OSS-Compatible):Configuration parameters for Redis Open-Source Edition

Specifies whether to check that the IP address of a client is added to a whitelist of the instance after password-free access is enabled for the instance. The client is deployed in the same virtual private cloud (VPC) as the instance. Valid values:

• yes: After you enable password-free access for the instance, you must also add the IP address of a client that is deployed in the same VPC as the instance to a whitelist of the instance before the client can connect to the instance.

  If the (error) ERR illegal address error is returned, the whitelist is improperly configured.

• no (default): After you enable password-free access for the instance, you can connect a client that is deployed in the same VPC as the instance to the instance without adding the IP address of the client to a whitelist of the instance.

The disabled commands. You can use this parameter to disable the commands that may have high risks or high time complexity based on your business requirements, such as FLUSHALL, FLUSHDB, KEYS, HGETALL, EVAL, EVALSHA, and SCRIPT.

Specifies whether to enable the Sentinel-compatible mode for standard instances or cluster instances in direct connection mode. Valid values:

• yes

• no (default)

Sets the minimum TLS version supported by the instance. Valid values:

• TLSv1 (default).

• TLSv1.1.

• TLSv1.2.

Specifies whether to enable AOF persistence for master nodes. Valid values:

• yes (default)

• no

  Note

  By default, data persistence by using Redis Database (RDB) snapshots is performed once a day. For more information, see Automatic or manual backup.

The pubsub parameter limits the output buffer for publish/subscribe clients. The default value is 33554432 8388608 60.

The normal parameter limits the output buffer for normal clients. The default value is 524288000 0 0.

The parameter format is <hard limit> <soft limit> <soft seconds>.

• <hard limit>: When the memory occupied by a client's output buffer reaches or exceeds the hard limit, the connection to the client is closed. The unit of the hard limit value is byte.

• <soft limit> and <soft seconds>: When the memory occupied by a client's output buffer reaches or exceeds the soft limit and this state persists for a duration greater than or equal to the number of seconds specified by soft seconds, the connection to the client is closed. The unit of the soft limit value is byte, and the unit of the soft seconds value is second.

Enables or disables dynamic hz. Valid values:

• yes (default): Enables the feature.

• no: Disables the feature.

The maximum number and size of key-value pairs stored in a hash. Ziplist encoding is used only if a hash meets both of the following conditions:

• The number of key-value pairs stored in the hash is smaller than the value of the hash-max-ziplist-entries parameter.

• The keys and values of key-value pairs stored in the hash are all smaller than the value of the hash-max-ziplist-value parameter. The keys and values are measured in bytes.

For instances compatible with Redis 7.0 or later, listpack is used as the default codec for hashing. When a hash object meets both of the following conditions, listpack encoding is used.

• The number of key-value pairs in the hash is less than the value of hash-max-listpack-entries.

• The string lengths of the keys and values in the hash are both less than the value of hash-max-listpack-value.

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, which specifies that each task is performed 10 times per second.

Specifies whether to enable command latency monitoring. Valid values:

• yes (default): Enables monitoring.

• no: Disables monitoring.

Specifies whether to enable lazyfree-based eviction. Valid values:

• yes: Enables the feature.

• no (default): Disables the feature.

Specifies whether to enable lazyfree-based deletion of expired keys. Valid values:

• yes (default): Enables the feature.

• no: Disables the feature.

Specifies whether the DEL command asynchronously deletes data based on lazyfree. Valid values:

• yes (default): Enables the feature.

• no: Disables the feature.

Specifies whether to automatically convert the FLUSHDB, FLUSHALL, SCRIPT FLUSH, and FUNCTION FLUSH commands to the Lazyfree asynchronous deletion mode. Valid values:

• yes: Enables the feature.

• no (default): Disables the feature.

The number of nodes that are not compressed at both ends of a list. Valid values: 0 to 65535.

• 0 (default): does not compress nodes of a list.

• A value in the range of 1 to 65535: does not compress the specified number of nodes at both ends of a list but compresses in-between nodes.

For instances compatible with Redis 6.0 or earlier, ziplist is used as the default codec for Lists (the list-max-ziplist-size parameter). For instances compatible with Redis 7.0 or later, listpack is used as the default codec for Lists (the list-max-listpack-size parameter).

• A positive value limits the length of the ziplist (listpack) on each quicklist node by the number of data items. For example, if this parameter is set to 5, the ziplist (listpack) of each quicklist node can contain a maximum of 5 data items.

• A negative value limits the length of the ziplist (listpack) on each quicklist node by the number of bytes occupied. Valid values:

  • -5: The size of the ziplist (listpack) on each quicklist node cannot exceed 64 KB.

  • -4: The size of the ziplist (listpack) on each quicklist node cannot exceed 32 KB.

  • -3: The size of the ziplist (listpack) on each quicklist node cannot exceed 16 KB.

  • -2 (default): The size of the ziplist (listpack) on each quicklist node cannot exceed 8 KB.

  • -1: The size of the ziplist (listpack) on each quicklist node cannot exceed 4 KB.

The policy used to evict keys if memory is exhausted. If the memory usage of your instance reaches the value of Maxmemory, data eviction is triggered. You can choose a data eviction policy based on your needs. Valid values:

• volatile-lru (default for Tair DRAM-based instances and Redis Open-Source Edition instances): evicts the LRU keys from keys that have a TTL configured regardless of whether the keys have expired.

• noeviction (default for Tair persistent memory-optimized instances): does not evict keys to make space when the memory limit is reached, but returns errors for write operations.

• volatile-lfu: evicts the LFU keys from keys that have a TTL configured.

• volatile-random: randomly evicts keys from keys that have a TTL configured.

• volatile-ttl: evicts the keys that have the shortest TTL from keys that have a TTL configured.

• allkeys-lru: evicts the LRU keys from all keys.

• allkeys-lfu: evicts the LFU keys from all keys.

• allkeys-random: randomly evicts keys from all keys.

The data eviction factor, used to set the delay for each data eviction. The value can range from 0 to 100. The default value is 10.

• Decreasing this value may reduce latency but will affect the effectiveness of data eviction.

• When write traffic is particularly high, you can increase this value, but the latency will increase. A value of 100 means that latency is ignored, and eviction continues until the memory drops below maxmemory or there are no more keys to evict.

The expired key (Expire) deletion factor, used to set the delay for each deletion of an expired key. The value can range from 1 to 10. The default value is 1. A larger value deletes expired keys faster but also consumes more CPU resources.

The types of events of which the server can notify clients. The value of this parameter is a combination of the following characters. This parameter setting applies to all databases in the instance. These notifications consume CPU resources. For more information, see Redis keyspace notifications.

• K: keyspace events. All events are published with a _keyspace@<db>_ prefix.

• E: keyevent events. All events 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. Clients are notified of operations to create, modify, and delete strings.

• l: events of list commands.

• s: events of set commands.

• h: events of hash commands.

• z: events of sorted set commands.

• x: expiration events. Clients may be notified when an expired key is deleted instead of when a key expires.

• e: eviction events. Clients are notified when a key is evicted based on maxmemory policies.

• A: all the preceding event types. This parameter is the alias for the g$lshzxe parameter. Example: AKE.

When the data in a Set collection meets the following conditions, intset encoding is used.

• All data in the collection are character objects.

• All are base-10 integers within the range of 64-bit signed integers.

The maximum memory that each macro node in a Stream can occupy. The value can range from 0 to 999,999,999,999,999.

The maximum number of entries that can be stored in each macro node in a Stream. The value can range from 0 to 999,999,999,999,999.

Sets the upper limit on the number of keys stored in the Tracking Table. The value can range from 0 to 1000000000. The default value is 1000000.

The timeout period. The system closes a connection to a client for the instance if the connection remains idle for the specified period of time. Valid values: 0 to 100000. Unit: seconds. The default value is 0, which indicates that no timeout period is specified.

The maximum number and size of key-value pairs stored in a sorted set. Ziplist encoding is used only if a sorted set meets both of the following conditions:

• The keys and values of key-value pairs stored in the sorted set are all smaller than the value of the zset-max-ziplist-value parameter. The keys and values are measured in bytes.

• The number of key-value pairs stored in the sorted set is smaller than the value of the zset-max-ziplist-entries parameter.

For instances compatible with Redis 7.0 or later, listpack is used as the default codec for Zset. When a Zset meets both of the following conditions, listpack encoding is used.

• The number of key-value pairs in the Zset is less than the value of zset-max-listpack-entries.

• The string lengths of the keys and values of the key-value pairs in the Zset are both less than the value of zset-max-listpack-value.

Specifies whether to pass through the client IP address to data nodes. Valid values:

• 0: Does not pass through the address. The IP addresses that access data nodes are the IP addresses of the proxy nodes.

• 1 (default): Passes through the address.

Enables or disables the Lua execution mode for read replicas. Valid values:

• 0 (default): Disables the Lua execution mode. Read replicas do not support Lua. Lua commands are processed by the primary node.

• 1: Enables the Lua execution mode. Only Lua scripts that contain read operations are forwarded to read replicas for processing.

Enables or disables directional forwarding for read-only account requests. Valid values:

• 0 (default): Disables directional forwarding. Requests from read-only accounts are allocated to all nodes, including the primary node, based on weights.

• 1: Enables directional forwarding. Requests from read-only accounts are forwarded to read replicas and not to the primary node.

The threshold for slow query logs in proxy nodes. Unit: millisecond (ms). The value can range from 30 to 2000. The default value is 500.

Specifies whether to enable the Sentinel-compatible mode for cluster instances in proxy mode or read/write splitting instances. Valid values:

• 1: enables the Sentinel-compatible mode.

• 0 (default): disables the Sentinel-compatible mode.

Enables or disables the feature that converts SUBSCRIBE commands to PSUBSCRIBE commands. Valid values:

• 0 (default): Disables the feature. The commands are not converted.

• 1: Enables the feature. The proxy node converts SUBSCRIBE commands to PSUBSCRIBE commands for processing.

  Note

  If you use PUB or SUB commands in Lua and cannot receive notifications on the subscribed channel, you can enable this feature.