Configuration

Redis Configuration

可於Redis網站下載各版本的redis.conf檔案，在檔案中以記載了每個參數的基本解釋。有關

Maxmemory policies

有關記憶體配置政策，可以參考GCP網站，包含如何分配Redis存取記憶記憶體的比例，以及超出記憶體上限限制後的刪除規則，亦整理於下方表格。

Parameter	Description	Acceptable values
activedefrag	Redis version 4.0, or later. Works to free up instance memory tied up by standard OSS Redis memory fragmentation behavior.	no (default) yes
lfu-decay-time	Redis version 4.0, or later. The time, in minutes, before the LFU frequency counter for a given key will be divided by two (or, if the counter is < 10, decremented by 1). See the REDIS.CONF file for additional information.	Positive integers of the 'long' data type (default=1)
lfu-log-factor	Redis version 4.0, or later. Determines how the frequency counter represents key hits. Before you modify the default configuration, read about how the lfu-log-factor configuration works in the REDIS.CONF file.	Positive integers of the 'long' data type (default=10)
maxmemory-gb	Designates an adjustable limit at which your eviction policy takes effect. For example, if you have a 10 GB instance and you set maxmemory-gb to 8, your eviction policy takes effect when your data occupies 8 GB of your instance memory. This leaves you 2 GB of memory as overhead. By default maxmemory-gb is set to your instance capacity. For details on how to best use the maxmemory-gb configuration, see the Memorystore memory management best practices.You can only modify the maxmemory-gb configuration using the gcloud command-line tool. The configuration is not available in the Google Cloud Console	Number of GB expressed as a whole number or decimal. Examples: 10 designates a maxmemory-gb of 10 GB. 1.5 designates a maxmemory-gb of 1.5 GB. maxmemory-gb can be reduced to a minimum of 20% of your instance capacity.
maxmemory-policy	Specifies the behavior Redis follows when the instance data reaches the maxmemory-gb limit. Refer to Maxmemory policies for a description of the behavior of each policy. For additional information about the open source Redis maxmemory policies, see the open source Redis LRU cache page	noeviction allkeys-lru volatile-lru (default) allkeys-random volatile-random volatile-ttl volatile-lfu (Redis version 4.0 and higher) allkeys-lfu (Redis version 4.0 and higher)
notify-keyspace-events	Allows clients to subscribe to notifications on certain keyspace events. See the Redis Keyspace Notifications page on the Redis site for more information.	"" (default) K Keyspace events, published with __keyspace@__ prefix. E Keyevent events, published with __keyevent@__ prefix. g Generic commands (non-type specific) like DEL, EXPIRE, or RENAME $ String commands l List commands s Set commands h Hash commands z Sorted set commands x Expired events (events generated every time a key expires) e Evicted events (events generated when a key is evicted for maxmemory) A Alias for g$lshzxe, so that the "AKE" string means all the events.
stream-node-max-bytes	Redis version 5.0, or later. The Redis stream data structure uses a radix tree to store items. The stream-node-max-bytes parameter designates the maximum number of bytes available to store items in a single tree node. Once this limit is reached new items are stored in a new tree node.	Integers 0 and higher. (default=4096) 0 designates a tree node of unlimited size.
stream-node-max-entries	Redis version 5.0, or later. The Redis stream data structure uses a radix tree to store items. The stream-node-max-entries parameter designates the number of items that can be stored in a single node. When this limit is reached, new items are stored in a new tree node.	Integers 0 and higher. (default=100) 0 designates a tree node with an unlimited number of items.
timeout	The number of seconds before idle client connections are terminated. However, if timeout is set to 0 idle clients do not timeout and remain connected until the client issues the termination.You can only modify the timeout configuration using the gcloud command-line tool. The configuration is not available in the Google Cloud Console	0 (default) Integers >= 120 Unit = seconds

補充：GCP Redis不可修改的參數

Parameter	Default
lua-time-limit	5000
hash-max-ziplist-entries	2048
hash-max-ziplist-value	1024
list-max-ziplist-size	-2
list-compress-depth .	0
set-max-intset-entries	512
zset-max-ziplist-entries	1024
zset-max-ziplist-value	1024
hll-sparse-max-byte	3000
activerehashing	是
hz	10
databases	16
maxclients	65000
slowlog-log-slower-than	10000
slowlog-max-len	128