本文主要是對於redis安裝與持久化中非常淺顯的知識進行介紹，並不深入瞭解，只接觸表面，對一些較複雜的內容也不過多描述。如文中有錯誤之處，望不吝賜教，謝謝~
一、Redis簡介
Redis（Remote Dictionary Server )，即遠程字典服務，是一個開源的使用ANSI C語言編寫、支持網絡、可基於內存亦可持久化的日誌型、Key-Value數據庫，並提供多種語言的API。
Redis是一款高性能的NOSQL系列的非關係型數據庫,redis在Java開發中主要用來存儲緩存用的數據以及在需要高速讀/寫的場合使用它快速讀/寫。
NoSQL技術，這是一種基於內存的數據庫，並且提供一定的持久化功能。
Redis和MongoDB是當前使用最廣泛的NoSQL，而就Redis技術而言，它的性能十分優越，可以支持每秒十幾萬此的讀/寫操作，其性能遠超數據庫，並且還支持集羣、分佈式、主從同步等配置，十分強大。
在一般情況下，不區分redis技術和redis數據庫，都稱作redis。
redis作爲一種非關係型數據庫，其是基於內存，不同於關係數據庫基於硬盤，其速度遠遠大於關係數據庫。但是由於內存的侷限性，所以對何種數據何時使用redis我們需要做出取捨。
一般對於讀操作較多且數據量較小的情況可考慮使用redis，例如“好友列表查詢”“排行榜”等等。
二、安裝redis
（1）進入github-redis下載redis壓縮包
（2）解壓下載下來的redis-64-3.0.503.zip ,直接打開便可使用。（其實這是綠色版本，不用安裝，下載下來解壓就好）。
- redis.windows.conf：配置文件
- redis-cli.exe：redis的客戶端
- redis-server.exe：redis服務器端
一般啓動好服務器端再打開客戶端就可以使用redis了。
三、redis持久化
由於redis的數據存儲在內存中，不便於保存（當服務器和客戶端關閉或電腦關機時，數據會丟失），爲了將redis中的數據保存在硬盤中，便需要持久化技術。
redis持久化分爲兩種方式一種是RDB（默認方式），一種是AOF方式。
（1）RDB
在redis.windows.conf配置文件中，有專門對RDB持久化的配置。
################################ 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
*“sava 900 1”*表示900秒內至少有一個鍵值發生改變，就執行持久化操作一次,相應的我們可以根據需要自行修改持久化條件。
每次持久化後的rdb文件會保存在redis的解壓目錄下。
（2）AOF：日誌記錄的方式，可以記錄每一次命令的操作並持久化
在redis.windows.conf配置文件中，有專門對AOF持久化的配置。
############################## APPEND ONLY MODE ###############################
# By default Redis asynchronously dumps the dataset on disk. This mode is
# good enough in many applications, but an issue with the Redis process or
# a power outage may result into a few minutes of writes lost (depending on
# the configured save points).
#
# The Append Only File is an alternative persistence mode that provides
# much better durability. For instance using the default data fsync policy
# (see later in the config file) Redis can lose just one second of writes in a
# dramatic event like a server power outage, or a single write if something
# wrong with the Redis process itself happens, but the operating system is
# still running correctly.
#
# AOF and RDB persistence can be enabled at the same time without problems.
# If the AOF is enabled on startup Redis will load the AOF, that is the file
# with the better durability guarantees.
#
# Please check http://redis.io/topics/persistence for more information.
appendonly no
"appendonly no"表示默認AOF方式是關閉的，若要打開，將no改爲yes即可。
# The fsync() call tells the Operating System to actually write data on disk
# instead of waiting for more data in the output buffer. Some OS will really flush
# data on disk, some other OS will just try to do it ASAP.
#
# Redis supports three different modes:
#
# no: don't fsync, just let the OS flush the data when it wants. Faster.
# always: fsync after every write to the append only log . Slow, Safest.
# everysec: fsync only one time every second. Compromise.
#
# The default is "everysec", as that's usually the right compromise between
# speed and data safety. It's up to you to understand if you can relax this to
# "no" that will let the operating system flush the output buffer when
# it wants, for better performances (but if you can live with the idea of
# some data loss consider the default persistence mode that's snapshotting),
# or on the contrary, use "always" that's very slow but a bit safer than
# everysec.
#
# More details please check the following article:
# http://antirez.com/post/redis-persistence-demystified.html
#
# If unsure, use "everysec".
# appendfsync always
appendfsync everysec
# appendfsync no
"appendfsync always"表示每一次操作都進行持久化，“appendfsync everysec”表示每隔一秒進行一次持久化操作（默認是這樣），“appendfsync no”表示不進行持久化操作。
每次持久化後的aof文件會保存在redis的解壓目錄下。
2020.03.07