Redis 学习之持久化机制、发布订阅、虚拟内存

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

appendonly yes

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly.aof"

# 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

[root@localhost bin]# cat appendonly.aof 
*2
$6
SELECT
$1
0
*3
$3
set
$4
addr
$2
bj

127.0.0.1:6379> subscribe tv1   订阅频道tv1
Reading messages... (press Ctrl-C to quit)
1) "subscribe"  
2) "tv1"
3) (integer) 1

127.0.0.1:6379> subscribe tv1 tv2   订阅频道tv1和tv2
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "tv1"
3) (integer) 1
1) "subscribe"
2) "tv2"
3) (integer) 2

127.0.0.1:6379> publish tv1 "Hello word"  #给频道tv1发布信息
(integer) 2     # tv1的订阅者2位
127.0.0.1:6379> publish tv2 "Hello tv2"   #给频道tv2发布信息
(integer) 1    # tv2的订阅者1位
127.0.0.1:6379> 

127.0.0.1:6379> subscribe tv1
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "tv1"
3) (integer) 1
1) "message"     #获取了tv1发布的信息
2) "tv1"
3) "Hello word"

127.0.0.1:6379> subscribe tv1 tv2
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "tv1"
3) (integer) 1
1) "subscribe"
2) "tv2"
3) (integer) 2
1) "message"   #获取了tv1发布的信息
2) "tv1"
3) "Hello word"
1) "message"  #获取了tv2发布的信息
2) "tv2"
3) "Hello tv2"