redis的持久化

################################ SNAPSHOTTING ################################
#
# Save the DB on disk:
#
# save <seconds> <changes>
#
# Will save the DB if both the given number of seconds and the given
# number of write operations against the DB occurred.
#
# In the example below the behaviour will be to save:
# after 900 sec (15 min) if at least 1 key changed
# after 300 sec (5 min) if at least 10 keys changed
# after 60 sec if at least 10000 keys changed
#
# Note: you can disable saving completely by commenting out all "save" lines.
#
# It is also possible to remove all the previously configured save
# points by adding a save directive with a single empty string argument
# like in the following example:
#
# save ""

save 900 1
save 300 10
save 60 10000

1. redis是一个内存数据库，当redis服务器重启，获取电脑重启，数据会丢失，我们可以将redis内存中的数据持久化保存到硬盘的文件中。
       2. redis持久化机制：
           1. RDB：默认方式，不需要进行配置，默认就使用这种机制
               * 在一定的间隔时间中，检测key的变化情况，然后持久化数据
               1. 编辑redis.windwos.conf文件
                   # after 900 sec (15 min) if at least 1 key changed
                   save 900 1
                   # after 300 sec (5 min) if at least 10 keys changed
                   save 300 10
                   # after 60 sec if at least 10000 keys changed
                   save 60 10000

               2. 重新启动redis服务器，并指定配置文件名称
                   D:\JavaWeb2018\day23_redis\资料\redis\windows-64\redis-2.8.9>redis-server.exe redis.windows.conf

           2. AOF：日志记录的方式，可以记录每一条命令的操作。可以每一次命令操作后，持久化数据
               1. 编辑redis.windwos.conf文件
                   appendonly no（关闭aof） --> appendonly yes （开启aof）

                   # appendfsync always ：每一次操作都进行持久化
                   appendfsync everysec ：每隔一秒进行一次持久化
                   # appendfsync no   ：不进行持久化