Tair (Redis® OSS-Compatible):Parameters that can be configured for Redis Open-Source Edition instances

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)

The earliest Transport Layer Security (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.

pubsub specifies the output buffer limits for publish/subscribe clients. Default value: 33554432 8388608 60.

normal specifies the output buffer limits of normal clients. Default value: 524288000 0 0.

The parameter value is specified in the following format: <hard limit> <soft limit> <soft seconds>.

• <hard limit>: When a client's output buffer size reaches or exceeds the hard limit, the client is disconnected. The hard limit value is measured in bytes.

• <soft limit> and <soft seconds>: A client is disconnected if its output buffer size remains larger than or equal to the soft limit value for a period of time that is 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.

Specifies whether to enable dynamic frequency control for background tasks. Valid values:

• yes (default): Enabled.

• no: Disabled.

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.

Starting from Redis 7.0, listpack is used as the default hash encoding method. Listpack encoding is used only if a hash meets both of the following conditions:

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

• The string length of each key and value in the hash is less than 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 tracking of per-command latencies. Valid values:

• yes (default): Enabled.

• no: Disabled.

Specifies whether to enable the eviction feature based on the lazyfree mechanism. Valid values:

• yes: Enabled.

• no (default): Disabled.

Specifies whether to delete expired keys based on the lazyfree mechanism. Valid values:

• yes (default): Enabled.

• no: Disabled.

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

• yes (default): Enabled.

• no.

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

• yes: Enable.

• no (default): Disabled.

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 versions compatible with Redis 6.0 and earlier, the default encoding method for lists is ziplist (the list-max-ziplist-size parameter), whereas for versions compatible with Redis 7.0 and later, the default is listpack (the list-max-listpack-size parameter).

• A positive number indicates the maximum number of elements in each ziplist (listpack) of a quicklist. For example, if you set this parameter to 5, each ziplist (listpack) of a quicklist can contain a maximum of five elements.

• A negative number indicates the maximum size of each ziplist (listpack) of a quicklist. Valid values:

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

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

  • -3: The size of each ziplist (listpack) of a quicklist 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 Eviction factor that is used to set the latency of each data eviction. Valid values: 0 to 100. Default value: 10.

• Lowering this value reduces the latency, but compromises the validity of data eviction.

• If large amounts of data are written, you can increase this value. In this case, the latency increases. A value of 100 indicates that the system keeps evicting data until the memory usage drops below the maxmemory limit or no keys can be evicted.

The Expire factor that is used to set the latency of each deletion of expired keys. Valid values: 1 to 10. Default value: 1. The larger the value, the faster expired keys are deleted and the more CPU resources are used.

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.

Specifies the maximum number of data entries for which a set supports intset encoding. A set uses intset encoding when the following conditions are met:

• All data entries in the set are strings.

• The set contains only radix-10 integers in the range of 64-bit signed integers.

The maximum amount of memory that each macro node in a stream can consume. Valid values: 0 to 999,999,999,999,999.

Specifies the maximum number of entries that can be stored on each macro node in a stream. Valid values: 0 to 999,999,999,999,999.

The maximum number of keys that can be stored in the tracking table. Valid values: 0 to 1000000000. Default value: 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.

Starting from Redis 7.0, listpack is used as the default sorted set encoding method. Listpack encoding is used only if a sorted set meets both of the following conditions:

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

• The string length of each member in the Zset is less than zset-max-listpack-value.

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

• 0: The client IP address is not passed to the data node. The IP address that accesses the data node is the IP address of the proxy node.

• 1 (default): The client IP address is passed to the data node.

Specifies whether to enable the Lua execution mode for read-only replicas. Valid values:

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

• 1: enables the Lua execution mode. Lua commands that contain only read operations are forwarded to read-only replicas for processing.

Specifies whether to enable directed forwarding of requests from read-only accounts. Valid values:

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

• 1: enables directed forwarding. Requests from read-only accounts are forwarded only to read-only replicas, not to the primary node.

The threshold for slow logs in proxy nodes. Unit: milliseconds (ms). Valid values: 30 to 2000. Default value: 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.

Specifies whether to enable the feature that converts SUBSCRIBE to PSUBSCRIBE. Valid values:

• 0 (default): disables the conversion.

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

  Note

  If you use 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.