第 32 章 Redis

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简介:


目录

32.1. Redis 安装
32.1.1. CentOS 7
32.1.2. CentOS 6
32.1.2.1. 主从同步
32.1.2.2. Sentinel
32.1.3. Ubuntu
32.1.4. 源码编译安装
32.1.5. Test Redis
32.2. /etc/redis.conf
32.2.1. 密码认证
32.2.2. maxmemory-policy TTL 过期策略配置
32.3. redis-cli - Command-line client to redis-server
32.3.1. 命令参数
32.3.1.1. password
32.3.1.2. raw
32.3.2. --latency Enter a special mode continuously sampling latency.
32.3.3. auth
32.3.4. MONITOR
32.3.5. info
32.3.6. save/bgsave/lastsave
32.3.7. config
32.3.8. keys
32.3.9. 字符串操作
32.3.9.1. set/get/del
32.3.9.2. setnx
32.3.10. expire/ttl
32.3.11. 获取 key 类型
32.3.12. LIST 数据类型
32.3.13. set 无序字符集合
32.3.14. zset (有序集合)
32.3.15. Pub/Sub 订阅与发布
32.3.16. flushdb 清空 Redis 数据
32.4. redis-benchmark 测试工具
32.5. Redis Cluster
32.6. Redis 通信协议
32.6.1. 切换DB
32.6.2. 监控
32.7. phpRedisAdmin
32.8. Redis 开发
32.8.1. 消息订阅与发布
32.9. A fast, light-weight proxy for memcached and redis
32.10. FAQ
32.10.1. 清空数据库
32.10.2. (error) MISCONF Redis is configured to save RDB snapshots

http://redis.io/

32.1. Redis 安装

32.1.1. CentOS 7

Netkiller OSCM 一键安装

curl -s https://raw.githubusercontent.com/oscm/shell/master/database/redis/redis.sh | bash
			

32.1.2. CentOS 6

安装fedora的YUM源,

rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-7.noarch.rpm
			

安装redis

# yum install redis

# chkconfig redis on

# service redis start
			

备份配置文件,

# cp /etc/redis.conf /etc/redis.conf.original
			

32.1.2.1. 主从同步

主从同步配置非常简单,只需在从服务器 /etc/redis.conf 文件中开启 slaveof 即可

slaveof 192.168.2.1 6379
				

查看 /var/log/redis/redis.log 日志,可以看到同步情况

				
[20274] 09 Jul 13:13:53 * Server started, Redis version 2.4.10
[20274] 09 Jul 13:13:53 * DB loaded from disk: 0 seconds
[20274] 09 Jul 13:13:53 * The server is now ready to accept connections on port 6379
[20274] 09 Jul 13:13:54 * Connecting to MASTER...
[20274] 09 Jul 13:13:54 * MASTER <-> SLAVE sync started
[20274] 09 Jul 13:13:54 * Non blocking connect for SYNC fired the event.
[20274] 09 Jul 13:13:54 * MASTER <-> SLAVE sync: receiving 672 bytes from master
[20274] 09 Jul 13:13:54 * MASTER <-> SLAVE sync: Loading DB in memory
[20274] 09 Jul 13:13:54 * MASTER <-> SLAVE sync: Finished with success
								
				

32.1.2.2. Sentinel

32.1.3. Ubuntu

$ sudo apt-get install redis-server
			
			
$ dpkg -s redis-server
Package: redis-server
Status: install ok installed
Priority: optional
Section: database
Installed-Size: 208
Maintainer: Chris Lamb <lamby@debian.org>
Architecture: amd64
Source: redis
Version: 2:1.2.6-1
Depends: libc6 (>= 2.7), adduser
Conffiles:
 /etc/redis/redis.conf a19bad63017ec19def2c3a8a07bdc362
 /etc/logrotate.d/redis-server 06755b99ef70d62a56cff94cbfc36de7
 /etc/init.d/redis-server 3742555c10ab16fdd67fcbaf92faf694
 /etc/bash_completion.d/redis-cli 848565df7f222dc03c8d5cb34b9e0188
Description: Persistent key-value database with network interface
 Redis is a key-value database in a similar vein to memcache but the dataset
 is non-volatile. Redis additionally provides native support for atomically
 manipulating and querying data structures such as lists and sets.
 .
 The dataset is stored entirely in memory and periodically flushed to disk.
Homepage: http://code.google.com/p/redis/
			
			
			
$ cat /etc/redis/redis.conf

# Redis configuration file example

# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes

# When run as a daemon, Redis write a pid file in /var/run/redis.pid by default.
# You can specify a custom pid file location here.
pidfile /var/run/redis.pid

# Accept connections on the specified port, default is 6379
port 6379

# If you want you can bind a single interface, if the bind option is not
# specified all the interfaces will listen for connections.
#
bind 127.0.0.1

# Close the connection after a client is idle for N seconds (0 to disable)
timeout 300

# Set server verbosity to 'debug'
# it can be one of:
# debug (a lot of information, useful for development/testing)
# notice (moderately verbose, what you want in production probably)
# warning (only very important / critical messages are logged)
loglevel notice

# Specify the log file name. Also 'stdout' can be used to force
# the demon to log on the standard output. Note that if you use standard
# output for logging but daemonize, logs will be sent to /dev/null
logfile /var/log/redis/redis-server.log

# Set the number of databases. The default database is DB 0, you can select
# a different one on a per-connection basis using SELECT <dbid> where
# dbid is a number between 0 and 'databases'-1
databases 16

################################ 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
save 900 1
save 300 10
save 60 10000

# Compress string objects using LZF when dump .rdb databases?
# For default that's set to 'yes' as it's almost always a win.
# If you want to save some CPU in the saving child set it to 'no' but
# the dataset will likely be bigger if you have compressible values or keys.
rdbcompression yes

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

# For default save/load DB in/from the working directory
# Note that you must specify a directory not a file name.
dir /var/lib/redis

################################# REPLICATION #################################

# Master-Slave replication. Use slaveof to make a Redis instance a copy of
# another Redis server. Note that the configuration is local to the slave
# so for example it is possible to configure the slave to save the DB with a
# different interval, or to listen to another port, and so on.
#
# slaveof <masterip> <masterport>

# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the slave to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the slave request.
#
# masterauth <master-password>

################################## SECURITY ###################################

# Require clients to issue AUTH <PASSWORD> before processing any other
# commands.  This might be useful in environments in which you do not trust
# others with access to the host running redis-server.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# requirepass foobared

################################### LIMITS ####################################

# Set the max number of connected clients at the same time. By default there
# is no limit, and it's up to the number of file descriptors the Redis process
# is able to open. The special value '0' means no limts.
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# maxclients 128

# Don't use more memory than the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys with an
# EXPIRE set. It will try to start freeing keys that are going to expire
# in little time and preserve keys with a longer time to live.
# Redis will also try to remove objects from free lists if possible.
#
# If all this fails, Redis will start to reply with errors to commands
# that will use more memory, like SET, LPUSH, and so on, and will continue
# to reply to most read-only commands like GET.
#
# WARNING: maxmemory can be a good idea mainly if you want to use Redis as a
# 'state' server or cache, not as a real DB. When Redis is used as a real
# database the memory usage will grow over the weeks, it will be obvious if
# it is going to use too much memory in the long run, and you'll have the time
# to upgrade. With maxmemory after the limit is reached you'll start to get
# errors for write operations, and this may even lead to DB inconsistency.
#
# maxmemory <bytes>

############################## APPEND ONLY MODE ###############################

# By default Redis asynchronously dumps the dataset on disk. If you can live
# with the idea that the latest records will be lost if something like a crash
# happens this is the preferred way to run Redis. If instead you care a lot
# about your data and don't want to that a single record can get lost you should
# enable the append only mode: when this mode is enabled Redis will append
# every write operation received in the file appendonly.log. This file will
# be read on startup in order to rebuild the full dataset in memory.
#
# Note that you can have both the async dumps and the append only file if you
# like (you have to comment the "save" statements above to disable the dumps).
# Still if append only mode is enabled Redis will load the data from the
# log file at startup ignoring the dump.rdb file.
#
# The name of the append only file is "appendonly.log"
#
# IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
# log file in background when it gets too big.

appendonly no

# The fsync() call tells the Operating System to actually write data on disk
# instead to wait 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 if one second passed since the last fsync. Compromise.
#
# The default is "always" that's the safer of the options. It's up to you to
# understand if you can relax this to "everysec" that will fsync every second
# or to "no" that will let the operating system flush the output buffer when
# it want, for better performances (but if you can live with the idea of
# some data loss consider the default persistence mode that's snapshotting).

appendfsync always
# appendfsync everysec
# appendfsync no

############################### ADVANCED CONFIG ###############################

# Glue small output buffers together in order to send small replies in a
# single TCP packet. Uses a bit more CPU but most of the times it is a win
# in terms of number of queries per second. Use 'yes' if unsure.
glueoutputbuf yes

# Use object sharing. Can save a lot of memory if you have many common
# string in your dataset, but performs lookups against the shared objects
# pool so it uses more CPU and can be a bit slower. Usually it's a good
# idea.
#
# When object sharing is enabled (shareobjects yes) you can use
# shareobjectspoolsize to control the size of the pool used in order to try
# object sharing. A bigger pool size will lead to better sharing capabilities.
# In general you want this value to be at least the double of the number of
# very common strings you have in your dataset.
#
# WARNING: object sharing is experimental, don't enable this feature
# in production before of Redis 1.0-stable. Still please try this feature in
# your development environment so that we can test it better.
shareobjects no
shareobjectspoolsize 1024
			
			
$ sudo /etc/init.d/redis-server start
			

32.1.4. 源码编译安装

这里仍然使用 Netkiller OSCM 安装,源码安装

curl -s https://raw.githubusercontent.com/oscm/shell/master/database/redis/source/redis-4.0.1.sh | bash
			

32.1.5. Test Redis

http://redis.io/commands

$ redis-cli info
redis_version:1.2.6
arch_bits:64
multiplexing_api:epoll
uptime_in_seconds:859
uptime_in_days:0
connected_clients:1
connected_slaves:0
used_memory:619490
used_memory_human:604.97K
changes_since_last_save:0
bgsave_in_progress:0
last_save_time:1311100746
bgrewriteaof_in_progress:0
total_connections_received:4
total_commands_processed:0
role:master

$ redis-cli set name neo
OK
$ redis-cli get name
neo

$ telnet localhost 6379
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost (127.0.0.1).
Escape character is '^]'.
get name
$3
neo
quit
Connection closed by foreign host.
			




原文出处:Netkiller 系列 手札
本文作者:陈景峯
转载请与作者联系,同时请务必标明文章原始出处和作者信息及本声明。

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