redis aof redis AoF file

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架构领航博主 2023-07-04 15:14:09

文章标签 redis aof Redis 持久化子进程 sed 文章分类 Redis 数据库

Redis4.0之后可以使用RDB AOF混合方式进行持久化了，说到持久化，持久化在Redis里有两种使用场景

1 服务器重启的时候可以加载持久化文件恢复数据

2 AOF由于是采用顺序写的方式，所以经过一定的时间旧的AOF就不够新了需要进行重写保证数据一致性

现在看看怎么开启混合模式

# When rewriting the AOF file, Redis is able to use an RDB preamble in the
# AOF file for faster rewrites and recoveries. When this option is turned
# on the rewritten AOF file is composed of two different stanzas:
#
#   [RDB file][AOF tail]
#
# When loading Redis recognizes that the AOF file starts with the "REDIS"
# string and loads the prefixed RDB file, and continues loading the AOF
# tail.
#
# This is currently turned off by default in order to avoid the surprise
# of a format change, but will at some point be used as the default.
aof-use-rdb-preamble no

　　把 aof-use-rdb-preamble 配成 yes就行了

　　上面的注释说了，开启了aof-use-rdb-preamble后，在对AOF进行重写的时候，AOF文件前半部分是RDB格式，后半部分是AOF格式

　　我们可以做个实验，下面是我在测试环境开启了aof-use-rdb-preamble后,手动执行下BGREWRITEAOF后生成的 appendonly.aof文件的内容

REDIS0008?redis-ver4.0.1?redis-bits繞?ctime聮~`?used-mem?? ?aof-preamble??repl-id(6c3378899b63bc4ebeaafaa09c27902d514eeb1f?repl-offset??? list1?77   /   appleorangegrape?e k1v1彝髖S[zb*2
$6
SELECT
$1
0
*3
$4
sadd
$8
gamedisk
$4
nioh
*3
$4
sadd
$8
gamedisk
$4
tomb

前半部分是RDB格式，后半部分是AOF格式