redis安裝配置使用過程的遇到的各類問題

###1.下載安裝後，如何正確的啓動redis 直接雙擊是很差的，由於沒有指定配置文件，採用默認的配置，所以最好的作法是啓動的同時指定配置文件。這就不奇怪，我在Windows中修改了n遍config文件卻一直不生效。更噁心的是，安裝結束後由兩個配置文件，還不知道哪一個是，原來是啓動的時候選擇的。

C:\Program Files\Redis>redis-server.exe redis.windows.conf

###2.正確的配置持久化的文件名 默認是有個持久化策略的，至於具體啥問題也不去研究。我就是用來作存儲的，不出問題就行。真是糟糕的學習方式，土地主通常。 在配置持久化文件的時候有兩個配置項：

# The filename where to dump the DB
dbfilename db\dump.rdb

# The working directory.
#
# The DB will be written inside this directory, with the filename specified
# above using the 'dbfilename' configuration directive.
# 
# The Append Only File will also be created inside this directory.
# 
# Note that you must specify a directory here, not a file name.
dir D:\data\redis\

dbfilename真的只是文件名，不要自做多情的覺得是相對路徑。因此上面的作法不對。應該是：

dbfilename dump.rdb

持久化的策略，默認是這樣的：

################################ 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

就是說，在900s內，一個key發生改變，則持久化到磁盤。相應的就是300s內10次改變，60s內10000次改變。因此，若是redis關掉了仍是會丟東西的。好比剛剛持久化到磁盤，你寫入了10個以上10000個一下的key，而後還不到300s，redi掛了，這些數據就麼了。

順便記錄下持久化的日誌格式：

[5948] 06 Nov 13:54:05.270 # Server started, Redis version 3.0.501
[5948] 06 Nov 13:54:05.277 * The server is now ready to accept connections on port 6379
[5948] 06 Nov 13:59:06.064 * 10 changes in 300 seconds. Saving...
[5948] 06 Nov 14:02:53.483 * Background saving started by pid 8460
[5948] 06 Nov 14:02:53.584 # fork operation complete
[5948] 06 Nov 14:02:53.585 * Background saving terminated with success

其實早就應該看備份命令

save
bgsave

###參考

• http://www.redis.net.cn/