Redis使用rdb文件恢复数据

只在单台redis恢复，未使用集群。

注意3个配置参数：

appendonly no
dbfilename dump.rdb
dir  ./data

appendonly 设置成no，redis启动时会把/var/lib/redis 目录下的dump.rdb 中的数据恢复。dir 和dbfilename 都可以设置。我测试时appendonly 设置成yes 时候不会将dump.rdb文件中的数据恢复。
测试如下：

[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-cli
127.0.0.1:6379> keys *
1) "user"
127.0.0.1:6379> CONFIG GET dir
1) "dir"
2) "/root/redis-4.0.12/data"
127.0.0.1:6379> set k1 11
OK
127.0.0.1:6379> set k2 11
OK
127.0.0.1:6379> set k3 11
OK
127.0.0.1:6379> set k4 11
OK
127.0.0.1:6379> set k5 11
OK
127.0.0.1:6379> set k6 11
OK
127.0.0.1:6379> set k7 11
OK
127.0.0.1:6379> set k8 11
OK
127.0.0.1:6379> set k9 11
OK
127.0.0.1:6379> set k10 11
OK

 连续set10个，就会产生备份

[root@iZbp143t3oxhfc3ar7jey0Z data]# ll
total 16
-rw-r--r-- 1 root root  168 Mar 21 14:38 dump.rdb
-rw-r--r-- 1 root root 9223 Mar 21 14:38 redis.log
[root@iZbp143t3oxhfc3ar7jey0Z data]# mv dump.rdb dump.rdb.bak
[root@iZbp143t3oxhfc3ar7jey0Z data]# ll
total 16
-rw-r--r-- 1 root root  168 Mar 21 14:38 dump.rdb.bak
-rw-r--r-- 1 root root 9223 Mar 21 14:38 redis.log

接着清空整个数据

127.0.0.1:6379> flushall
OK
127.0.0.1:6379> exit

[root@iZbp143t3oxhfc3ar7jey0Z data]# ll
total 20
-rw-r--r-- 1 root root   93 Mar 21 14:40 dump.rdb
-rw-r--r-- 1 root root  168 Mar 21 14:38 dump.rdb.bak
-rw-r--r-- 1 root root 9270 Mar 21 14:40 redis.log

也会产生一个新的rdb,在重新启动redis

[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-cli shutdown
[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-server redis.conf
[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# lsof -i:6379
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
redis-ser 18150 root    6u  IPv6 534722      0t0  TCP *:6379 (LISTEN)
redis-ser 18150 root    7u  IPv4 534723      0t0  TCP *:6379 (LISTEN)
[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-cli
127.0.0.1:6379> keys *
(empty list or set)
127.0.0.1:6379> exit

发现没有数据，是清空后有一个空的备份文件

[root@iZbp143t3oxhfc3ar7jey0Z data]# ll
total 20
-rw-r--r-- 1 root root    93 Mar 21 14:41 dump.rdb
-rw-r--r-- 1 root root   168 Mar 21 14:38 dump.rdb.bak
-rw-r--r-- 1 root root 12281 Mar 21 14:41 redis.log
[root@iZbp143t3oxhfc3ar7jey0Z data]# rm -rf dump.rdb
[root@iZbp143t3oxhfc3ar7jey0Z data]# mv dump.rdb.bak dump.rdb
[root@iZbp143t3oxhfc3ar7jey0Z data]# ll
total 16
-rw-r--r-- 1 root root   168 Mar 21 14:38 dump.rdb
-rw-r--r-- 1 root root 12281 Mar 21 14:41 redis.log
[root@iZbp143t3oxhfc3ar7jey0Z data]#

[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-cli shutdown
[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-server redis.conf
[root@iZbp143t3oxhfc3ar7jey0Z redis-4.0.12]# redis-cli
127.0.0.1:6379>  keys *
 1) "k10"
 2) "k3"
 3) "k4"
 4) "k2"
 5) "k5"
 6) "k6"
 7) "k1"
 8) "k9"
 9) "user"
10) "k7"
11) "k8"
127.0.0.1:6379>

把之前产生的rdb文件改名，重新启动，发现就有数据了。