前言

原有的内存淘汰机制没有设置导致redis持久化的时候，内存直接爆掉

步骤

修改配置 | 重启服务

修改redis.conf的配置文件,并重启redis服务

############################## MEMORY MANAGEMENT ################################

# Set a memory usage limit to the specified amount of bytes.

# When the memory limit is reached Redis will try to remove keys

# according to the eviction policy selected (see maxmemory-policy).

#

# If Redis can't remove keys according to the policy, or if the policy is

# set to 'noeviction', Redis will start to reply with errors to commands

# that would use more memory, like SET, LPUSH, and so on, and will continue

# to reply to read-only commands like GET.

#

# This option is usually useful when using Redis as an LRU or LFU cache, or to

# set a hard memory limit for an instance (using the 'noeviction' policy).

#

# WARNING: If you have replicas attached to an instance with maxmemory on,

# the size of the output buffers needed to feed the replicas are subtracted

# from the used memory count, so that network problems / resyncs will

# not trigger a loop where keys are evicted, and in turn the output

# buffer of replicas is full with DELs of keys evicted triggering the deletion

# of more keys, and so forth until the database is completely emptied.

#

# In short... if you have replicas attached it is suggested that you set a lower

# limit for maxmemory so that there is some free RAM on the system for replica

# output buffers (but this is not needed if the policy is 'noeviction').

#

maxmemory 32212254720

# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory

# is reached. You can select among five behaviors:

#内存不足的情况下,有以下几种移除key的方式供你选择

# volatile-lru -> Evict using approximated LRU among the keys with an expire set.

# allkeys-lru -> Evict any key using approximated LRU.

# volatile-lfu -> Evict using approximated LFU among the keys with an expire set.

# allkeys-lfu -> Evict any key using approximated LFU.

# volatile-random -> Remove a random key among the ones with an expire set.

# allkeys-random -> Remove a random key, any key.

# volatile-ttl -> Remove the key with the nearest expire time (minor TTL)

# noeviction -> Don't evict anything, just return an error on write operations.

#

# LRU means Least Recently Used

# LFU means Least Frequently Used

#

# Both LRU, LFU and volatile-ttl are implemented using approximated

# randomized algorithms.

#

# Note: with any of the above policies, Redis will return an error on write

# operations, when there are no suitable keys for eviction.

#

# At the date of writing these commands are: set setnx setex append

# incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd

# sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby

# zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby

# getset mset msetnx exec sort

#

# The default is:

#volatile-ttl 移除设置过过期时间且最近要过期的key

maxmemory-policy volatile-ttl

# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated

# algorithms (in order to save memory), so you can tune it for speed or

# accuracy. For default Redis will check five keys and pick the one that was

# used less recently, you can change the sample size using the following

# configuration directive.

#

# The default of 5 produces good enough results. 10 Approximates very closely

# true LRU but costs more CPU. 3 is faster but not very accurate.

#

# maxmemory-samples 5

# Starting from Redis 5, by default a replica will ignore its maxmemory setting

# (unless it is promoted to master after a failover or manually). It means

# that the eviction of keys will be just handled by the master, sending the

# DEL commands to the replica as keys evict in the master side.

#

# This behavior ensures that masters and replicas stay consistent, and is usually

# what you want, however if your replica is writable, or you want the replica to have

# a different memory setting, and you are sure all the writes performed to the

# replica are idempotent, then you may change this default (but be sure to understand

# what you are doing).

#

# Note that since the replica by default does not evict, it may end using more

# memory than the one set via maxmemory (there are certain buffers that may

# be larger on the replica, or data structures may sometimes take more memory and so

# forth). So make sure you monitor your replicas and make sure they have enough

# memory to never hit a real out-of-memory condition before the master hits

# the configured maxmemory setting.

#

# replica-ignore-maxmemory yes

动态修改 | 无需重启

scrm:0>config set maxmemory 32212254720

"OK"

scrm:0>config get maxmemory

1) "maxmemory"

2) "32212254720"

scrm:0>config set maxmemory-policy volatile-ttl

"OK"

scrm:0>config gscrm-taibao:0>et maxmemory-policy

1) "maxmemory-policy"

2) "volatile-ttl"