Redis 使用场景
1、性能: 不经常变动的数据放入缓存
我们在碰到需要执行耗时特别久，且结果不频繁变动的SQL，就特别适合将运行结果放入缓存。这样，后面的请求就去缓存中读取，使得请求能够迅速响应。
2、迸发： 在高迸发的情况下使用缓存
在大并发的情况下，所有的请求直接访问数据库，数据库会出现连接异常。这个时候，就需要使用redis做一个缓冲操作，让请求先访问到redis，而不是直接访问数据库。
install Redis
wget http://download.redis.io/releases/redis-5.0.5.tar.gztar xzf redis-5.0.5.tar.gzcd redis-5.0.5make MALLOC=libcmake PREFIX=/usr/local/redis/ install
tree /usr/local/redis/bin/
/usr/local/redis/bin/├── redis-benchmark // Redis性能测试工具├── redis-check-aof // 对更新日志appendonly.aof 检查, 是否可用├── redis-check-rdb├── redis-cli // Redis命令行客户端操作工具├── redis-sentinel -> redis-server└── redis-server //Redis服务器的daemon启动程序0 directories, 6 files
配置并启动
echo 'PATH=/usr/local/redis/bin/:$PATH' >> /etc/profile source /etc/profilewhich redis-server cp /usr/local/lib/redis-5.0.5/redis.conf /usr/local/redis/conf/ redis-server /usr/local/redis/conf/redis.conf & -- 启动 redis-cli shutdown -- 关闭
在生产环境中，需要将redis作为一个deamon进程去启动，每次系统启动的时候，redis服务会跟着启动。
进入redis目录下面，然后在进入utils目录，可以看到，有一个redis_init_script文件。
将这个文件拷贝到/etc/init.d/redis_6379下面
cp /usr/local/lib/redis-5.0.5/utils/redis_init_script /etc/init.d/redis.6379 vim /usr/local/redis/conf/redis.6379.conf daemonize yes # 让redis以daemon进程运行 dir /usr/local/redis/var/ # 设置持久化文件的位置
让redis跟随系统启动
在redis_6379脚本中，最上面，加入两行注释
# chkconfig: 2345 90 10# description: Redis is a persistent key-value database
认证
修改配置文件并重启 vim redis.conf requirepass password123 redis-cli shutdown redis-server /usr/local/redis/conf/redis.conf & [root@caoc-1 conf]# redis-cli 127.0.0.1:6379> set k v # 设置k v 提示需要认证(error) NOAUTH Authentication required.127.0.0.1:6379> auth password123 # 认证OK127.0.0.1:6379> set k v # 设置成功OK127.0.0.1:6379> get k"v" or 登录方式 redis-cli -a password
改名和禁用命令
rename-command CONFIG "" # 禁用命令 rename-command set sets # 改名命令
python 操作redis
pip install redis
# python
Python 2.7.5 (default, Oct 30 2018, 23:45:53) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux2Type "help", "copyright", "credits" or "license" for more information.>>> import redis>>> r = redis.Redis(host='127.0.0.1', port=6379, password='luciencao', db=0)>>> pipe = r.pipeline()>>> pipe.set('name','orange')>>> pipe.execute()[True]>>> print(r.get('name'))orange>>>
Redis 主从复制
主
bind 0.0.0.0port 6379 appendonly yes ...
从
bind 0.0.0.0 port 6379 appendonly yes replicaof 192.168.1.19 6379masterauth password ...
Redis-clusters 配置
集群采用6个节点, 3个master 和分别对应的1个 salve , 创建对应的7000-7005目录
mkdir -p /home/redis-clusters/{ 7000,7001,7002,7003,7004,7005}/{conf,var,run,log} [root@redis redis-clusters]# tree .
.├── 7000│ ├── conf│ │ └── redis.7000.conf│ ├── log│ │ └── redis.7000.log│ ├── run│ └── var├── 7001│ ├── conf│ │ └── redis.7001.conf│ ├── log│ │ └── redis.7000.log│ ├── run│ └── var...
集群配置文件 redis.7000.conf
需要区别的配置
port 7000pidfile /home/redis-clusters/7000/run/redis_7000.pidlogfile /home/redis-clusters/7000/log/redis.7000.logdir /home/redis-clusters/7000/var/masterauth luciencaorequirepass luciencaoappendonly yes
完整配置:
[root@caoc-1 redis-clusters]# egrep -v "^$|^#" 7000/conf/redis.7000.conf bind 0.0.0.0protected-mode yesport 7000tcp-backlog 511timeout 0tcp-keepalive 300daemonize yessupervised nopidfile /home/redis-clusters/7000/run/redis_7000.pidloglevel noticelogfile /home/redis-clusters/7000/log/redis.7000.logdatabases 16always-show-logo yessave 900 1save 300 10save 60 10000stop-writes-on-bgsave-error yesrdbcompression yesrdbchecksum yesdbfilename dump.rdbdir /home/redis-clusters/7000/var/masterauth luciencaoreplica-serve-stale-data yesreplica-read-only yesrepl-diskless-sync norepl-diskless-sync-delay 5repl-disable-tcp-nodelay noreplica-priority 100requirepass luciencaolazyfree-lazy-eviction nolazyfree-lazy-expire nolazyfree-lazy-server-del noreplica-lazy-flush noappendonly yesappendfilename "appendonly.aof"appendfsync everysecno-appendfsync-on-rewrite noauto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mbaof-load-truncated yesaof-use-rdb-preamble yeslua-time-limit 5000cluster-enabled yescluster-config-file nodes-7000.confcluster-node-timeout 15000slowlog-log-slower-than 10000slowlog-max-len 128latency-monitor-threshold 0notify-keyspace-events ""hash-max-ziplist-entries 512hash-max-ziplist-value 64list-max-ziplist-size -2list-compress-depth 0set-max-intset-entries 512zset-max-ziplist-entries 128zset-max-ziplist-value 64hll-sparse-max-bytes 3000stream-node-max-bytes 4096stream-node-max-entries 100activerehashing yesclient-output-buffer-limit normal 0 0 0client-output-buffer-limit replica 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60hz 10dynamic-hz yesaof-rewrite-incremental-fsync yesrdb-save-incremental-fsync yes
启动服务
redis-server 7000/conf/redis.7000.conf redis-server 7001/conf/redis.7001.conf redis-server 7002/conf/redis.7002.conf redis-server 7003/conf/redis.7003.conf redis-server 7004/conf/redis.7004.conf redis-server 7005/conf/redis.7005.conf
启动集群
redis-cli --cluster create 0.0.0.0:7000 0.0.0.0:7001 0.0.0.0:7002 0.0.0.0:7003 0.0.0.0:7004 0.0.0.0:7005 --cluster-replicas 1 -a luciencao
输入 yes 打印如下
[OK] All 16384 slots covered 这表示集群中的 16384 个槽都有至少一个主节点在处理， 集群运作正常。
>>> Performing hash slots allocation on 6 nodes...Master[0] -> Slots 0 - 5460Master[1] -> Slots 5461 - 10922Master[2] -> Slots 10923 - 16383Adding replica 0.0.0.0:7004 to 0.0.0.0:7000Adding replica 0.0.0.0:7005 to 0.0.0.0:7001Adding replica 0.0.0.0:7003 to 0.0.0.0:7002>>> Trying to optimize slaves allocation for anti-affinity[WARNING] Some slaves are in the same host as their masterM: 814ff7a5c1e1affa45ff741018d38cc504114650 0.0.0.0:7000 slots:[0-5460] (5461 slots) masterM: 9a46b15737ba55d8c09cb776d6f82796aca35296 0.0.0.0:7001 slots:[5461-10922] (5462 slots) masterM: 9042f31ec13b6ace52833e2a5c83aa0178f7019e 0.0.0.0:7002 slots:[10923-16383] (5461 slots) masterS: 59d4a5f73ffb82d294e684ac07700eb5e0cd8b0a 0.0.0.0:7003 replicates 9a46b15737ba55d8c09cb776d6f82796aca35296S: 03bfaa6794ef1157b6f6b8e071d0575646105abc 0.0.0.0:7004 replicates 9042f31ec13b6ace52833e2a5c83aa0178f7019eS: db800ec138a395f05d68895ee3301835a412c314 0.0.0.0:7005 replicates 814ff7a5c1e1affa45ff741018d38cc504114650Can I set the above configuration? (type 'yes' to accept): yes>>> Nodes configuration updated>>> Assign a different config epoch to each node>>> Sending CLUSTER MEET messages to join the clusterWaiting for the cluster to join..>>> Performing Cluster Check (using node 0.0.0.0:7000)M: 814ff7a5c1e1affa45ff741018d38cc504114650 0.0.0.0:7000 slots:[0-5460] (5461 slots) master 1 additional replica(s)M: 9a46b15737ba55d8c09cb776d6f82796aca35296 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s)S: 59d4a5f73ffb82d294e684ac07700eb5e0cd8b0a 127.0.0.1:7003 slots: (0 slots) slave replicates 9a46b15737ba55d8c09cb776d6f82796aca35296S: db800ec138a395f05d68895ee3301835a412c314 127.0.0.1:7005 slots: (0 slots) slave replicates 814ff7a5c1e1affa45ff741018d38cc504114650S: 03bfaa6794ef1157b6f6b8e071d0575646105abc 127.0.0.1:7004 slots: (0 slots) slave replicates 9042f31ec13b6ace52833e2a5c83aa0178f7019eM: 9042f31ec13b6ace52833e2a5c83aa0178f7019e 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s)[OK] All nodes agree about slots configuration.>>> Check for open slots...>>> Check slots coverage...[OK] All 16384 slots covered.