redis 消息队列（发布订阅）、持久化(RDB、AOF)、集群(cluster)
一：订阅：
192.168.10.205:6379> SUBSCRIBE test Reading messages... (press Ctrl-C to quit) 1) "subscribe" 2) "test" 3) (integer) 1 在另一个终端向订阅test发布消息： 127.0.0.1:6379> PUBLISH test1 hello (integer) 0 上一个终端的订阅就收到了消息： 1) "message" 2) "test" 3) "hello"
二：redis持久化：
redis支持两种数据持久化，一种是rdb，会在指定的数据间隔内把内存的数据快照到文件，aof将所有服务端执行的命令备查，在服务重启的时候全部执行以此
rdb在断电的时候会丢失部分内网，aof不会
1、使用rdb持久化redis数据：
配置文件的快照时间设置：
快照是fork出一个当前的进程在后台进行快照，不会影响当前的进程，先写一个临时文件，写完以后将临时文件替换旧的文件。这个文件任何时候都是一个完整的副本
save 900 1 #900秒以内有1个key发生变化就快照
save 300 10 #300秒以内有10个key发生变化就快照
save 60 10000 #60秒内有10000个key变化就快照
rdbcompression yes #持久化到RDB文件时，是否压缩，“yes”为压缩，“no”则反之
rdbchecksum yes #读取和写入的时候是否支持CRC64校验，默认是开启的
dbfilename dump.rdb #保存的文件的名称
dir /usr/local/redis #快照文件的保存路径
SAVE 与 BGSAVE:
SAVE:阻塞保存
BGSAVE：在后台保存，不阻塞
KILL -9 会丢失自上次保存以后到现在的数据
2、使用AOF进行持久化：
appendonly yes #默认为no，改为yes
appendfilename "appendonly.aof" #保存的文件名，路径为rdb指定的file目录
关闭服务在启动即可
三：redis主从：
一个主服务器可以有多个从服务器，而且从服务器也可以有主服务器，主从复制时非阻塞的，通过fork主进程
主服务器收到从服务器的sync命令，就在后台执行bgsave，执行完毕后将保持的rdb文件发给客户端，客户端收到后将rdb载入到内存，新版本的支持增量备份
通过info命令查看默认配置：
# Replication role:master #默认较色为主服务器 connected_slaves:0 master_repl_offset:0 repl_backlog_active:0 repl_backlog_size:1048576 repl_backlog_first_byte_offset:0 repl_backlog_histlen:0
在从服务器执行命令：
127.0.0.1:6379> SLAVEOF 192.168.10.205 6379 #主服务器的地址和端口
OK
查看从服务器的info信息：
# Replication role:slave #角色为从服务器 master_host:192.168.10.205 #主服务器的地址 master_port:6379 #主服务器的端口 master_link_status:up master_last_io_seconds_ago:8 master_sync_in_progress:0 slave_repl_offset:29 slave_priority:100 slave_read_only:1 connected_slaves:0 master_repl_offset:0 repl_backlog_active:0 repl_backlog_size:1048576 repl_backlog_first_byte_offset:0 repl_backlog_histlen:0
主服务器的状态信息：
# Replication role:master #角色为主服务器 connected_slaves:1 slave0:ip=192.168.10.206,port=6379,state=online,offset=471,lag=0 #从服务器的地址和端口 master_repl_offset:471 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:2 repl_backlog_histlen:470
从服务器无法写,如下：
127.0.0.1:6379> set a x (error) READONLY You can't write against a read only slave.
三：redis集群：
四种大方案：
1、客户端分片，优势是比较灵活，不存在单点故障，缺点是添加节点需要重新配置，数据要手动同步
2、代理：代理分片，有proxy代理取数据，可以为proxy配置算法，如Twemproxy
3、Redis Cluster:在3.0版本以后支持，无中心，在某种情况下会造成数据丢失
4、Coodis：豌豆荚的开源方案
使用redis cluster：
需要至少6个机器，3主3从，下面创建8个客户端，另外2个做备用
先将配置文件复制到/opt，然后创建8个目录并生成8个不同端口、不同pid和不同rdb文件的redis.conf配置文件：
[root@node5 ~]# cd /opt/ [root@node5 opt]# mkdir `seq 7001 7008` [root@node5 opt]# cp /etc/redis/6379.conf . [root@node5 opt]# sed 's/6379/7001/g' 6379.conf >> 7001/redis.conf [root@node5 opt]# sed 's/7001/7002/g' 6379.conf >> 7002/redis.conf [root@node5 opt]# sed 's/7002/7003/g' 6379.conf >> 7003/redis.conf [root@node5 opt]# sed 's/7003/7004/g' 6379.conf >> 7004/redis.conf [root@node5 opt]# sed 's/7004/7005/g' 6379.conf >> 7005/redis.conf [root@node5 opt]# sed 's/7005/7006/g' 6379.conf >> 7006/redis.conf [root@node5 opt]# sed 's/7006/7007/g' 6379.conf >> 7007/redis.conf [root@node5 opt]# sed 's/7007/7008/g' 6379.conf >> 7008/redis.conf
批量启动redis：
[root@node5 opt]# for i in `seq 7001 7008`;do cd /opt/$i && /usr/local/redis/bin/redis-server /opt/$i/redis.conf; done
确认端口都已经启动成功：
[root@node5 opt]# redis-cli -h 192.168.10.205 -p 7001 192.168.10.205:7001> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7002 192.168.10.205:7002> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7003 192.168.10.205:7003> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7004 192.168.10.205:7004> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7005 192.168.10.205:7005> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7006 192.168.10.205:7006> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7007 192.168.10.205:7007> [root@node5 opt]# redis-cli -h 192.168.10.205 -p 7008 192.168.10.205:7008>
安装ruby管理工具：
[root@node5 opt]# yum install ruby rubygems -y [root@node5 opt]# gem install redis Successfully installed redis-3.2.2 1 gem installed Installing ri documentation for redis-3.2.2... Installing RDoc documentation for redis-3.2.2..
复制ruby的管理脚本：
[root@node5 ~]# cp /root/redis-3.0.7/src/redis-trib.rb /usr/local/bin/redis-trib #是一个ruby脚本，方便redis管理
功能介绍：
root@node5 ~]# redis-trib help Usage: redis-trib <command> <options> <arguments ...> help (show this help) del-node host:port node_id #删除节点 reshard host:port #重新分片 --timeout <arg> --pipeline <arg> --slots <arg> --to <arg> --yes --from <arg> fix host:port --timeout <arg> create host1:port1 ... hostN:portN #创建集群 --replicas <arg> rebalance host:port --timeout <arg> --simulate --pipeline <arg> --threshold <arg> --use-empty-masters --auto-weights --weight <arg> call host:port command arg arg .. arg add-node new_host:new_port existing_host:existing_port #添加节点 --slave --master-id <arg> check host:port #检测节点 import host:port --replace --copy --from <arg> set-timeout host:port milliseconds info host:port
创建集群：
[root@node5 ~]# redis-trib create --replicas 1 192.168.10.205:7001 192.168.10.205:7002 192.168.10.205:7003 192.168.10.205:7004 192.168.10.205:7005 192.168.10.205:7006 >>> Creating cluster >>> Performing hash slots allocation on 6 nodes... Using 3 masters: 192.168.10.205:7001 192.168.10.205:7002 192.168.10.205:7003 Adding replica 192.168.10.205:7004 to 192.168.10.205:7001 Adding replica 192.168.10.205:7005 to 192.168.10.205:7002 Adding replica 192.168.10.205:7006 to 192.168.10.205:7003 M: 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 slots:0-5460 (5461 slots) master M: 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 slots:5461-10922 (5462 slots) master M: 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 slots:10923-16383 (5461 slots) master S: 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 replicates 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 S: 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 replicates 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 S: 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 replicates 8f2f43ef9008f299786b3f02446a0ac0d20dde35 Can 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 cluster Waiting for the cluster to join.. >>> Performing Cluster Check (using node 192.168.10.205:7001) M: 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 #ID及IP和端口 slots:0-5460 (5461 slots) master #本机对应的分片位置，0-5460 M: 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 slots:5461-10922 (5462 slots) master #本机对应的分片位置，5461-10922 #ID及IP和端口 M: 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 slots:10923-16383 (5461 slots) master #本机对应的分片位置，10923-16383 #ID及IP和端口 M: 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 slots: (0 slots) master replicates 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 #master的ID M: 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 slots: (0 slots) master replicates 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 #master的ID M: 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 slots: (0 slots) master replicates 8f2f43ef9008f299786b3f02446a0ac0d20dde35 #master的ID [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered.
连接到集群：
[root@node5 ~]# redis-cli -h 192.168.10.205 -c -p 7001
查看集群信息：
# Replication role:master connected_slaves:1 slave0:ip=192.168.10.205,port=7004,state=online,offset=407,lag=0 master_repl_offset:407 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:2 repl_backlog_histlen:406
操作集群：
192.168.10.205:7001> set key1 value1 -> Redirected to slot [9189] located at 192.168.10.205:7002 OK 192.168.10.205:7002> set key2 value2 -> Redirected to slot [4998] located at 192.168.10.205:7001 OK 192.168.10.205:7001> set key3 value3 OK 192.168.10.205:7001> set key4 value4 -> Redirected to slot [13120] located at 192.168.10.205:7003 OK 192.168.10.205:7003> set key5 value5 -> Redirected to slot [9057] located at 192.168.10.205:7002 OK 192.168.10.205:7002> set key6 value6 -> Redirected to slot [4866] located at 192.168.10.205:7001 OK 192.168.10.205:7001> set key7 value7 OK 192.168.10.205:7001> set key8 value8 -> Redirected to slot [13004] located at 192.168.10.205:7003 #插入的数据是轮训写入到各个redis server OK
cluster nodes：列出当前的主从
192.168.10.205:7003> CLUSTER nodes 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 myself,master - 0 0 3 connected 10923-16383 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 master - 0 1458558870837 2 connected 5461-10922 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 slave 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 0 1458558869829 4 connected 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 slave 8f2f43ef9008f299786b3f02446a0ac0d20dde35 0 1458558868820 6 connected 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 slave 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 0 1458558870334 5 connected 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 master - 0 1458558869829 1 connected 0-5460
cluster info：当前的状态：
192.168.10.205:7003> CLUSTER INFO cluster_state:ok cluster_slots_assigned:16384 cluster_slots_ok:16384 cluster_slots_pfail:0 cluster_slots_fail:0 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:3 cluster_stats_messages_sent:2911 cluster_stats_messages_received:2911
向集群中添加节点：
[root@node5 ~]# redis-trib add-node 192.168.10.205:7007 192.168.10.205:7001
要添加的节点和端口 添加到的目的节点和端口
[root@node5 ~]# redis-trib add-node 192.168.10.205:7007 192.168.10.205:7001 >>> Adding node 192.168.10.205:7007 to cluster 192.168.10.205:7001 >>> Performing Cluster Check (using node 192.168.10.205:7001) M: 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 slots:0-5460 (5461 slots) master 1 additional replica(s) M: 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 slots:10923-16383 (5461 slots) master 1 additional replica(s) S: 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 slots: (0 slots) slave replicates 8f2f43ef9008f299786b3f02446a0ac0d20dde35 M: 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 slots:5461-10922 (5462 slots) master 1 additional replica(s) S: 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 slots: (0 slots) slave replicates 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 S: 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 slots: (0 slots) slave replicates 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. >>> Send CLUSTER MEET to node 192.168.10.205:7007 to make it join the cluster. [OK] New node added correctly.
添加主机以后需要重新分片：
[root@node5 ~]# redis-trib reshard 192.168.10.205:7007
连接到新添加的节点查询信息：
[root@node5 ~]# redis-cli -h 192.168.10.205 -p 7007 192.168.10.205:7007> KEYS * (empty list or set) 192.168.10.205:7007> CLUSTER NODES 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 master - 0 1458560205983 2 connected 5728-10922 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 master - 0 1458560204471 3 connected 11189-16383 19a5bb651f4b182a0e3dd49154323d31c1524167 192.168.10.205:7007 myself,master - 0 0 7 connected 0-265 5461-5727 10923-11188 #已经有了分片信息 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 slave 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 0 1458560204977 2 connected 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 slave 8f2f43ef9008f299786b3f02446a0ac0d20dde35 0 1458560205482 3 connected 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 master - 0 1458560204471 1 connected 266-5460 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 slave 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 0 1458560204977 1 connected
为新添加的主节点添加从节点：
[root@node5 ~]# redis-trib add-node 192.168.10.205:7008 192.168.10.205:7001 #添加一个节点 #登陆到从节点进行配置 [root@node5 ~]# redis-cli -h 192.168.10.205 -c -p 7008 #登陆到要备用的从节点 192.168.10.205:7008> CLUSTER replicate 19a5bb651f4b182a0e3dd49154323d31c1524167 #指定主节点的ID即可 OK
再次查看集群信息：
192.168.10.205:7008> CLUSTER nodes 19806347e07d4b341e3ddff16136241d16e410c4 192.168.10.205:7005 slave 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 0 1458560717276 2 connected ab146fb5881064a6375da76f861e205d2d702140 192.168.10.205:7008 myself,slave 19a5bb651f4b182a0e3dd49154323d31c1524167 0 0 0 connected #已经是从节点并连接了 32d95f05196786500187137f30040968cc8b6521 192.168.10.205:7004 slave 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 0 1458560716772 1 connected 8f2f43ef9008f299786b3f02446a0ac0d20dde35 192.168.10.205:7003 master - 0 1458560715764 3 connected 11189-16383 19a5bb651f4b182a0e3dd49154323d31c1524167 192.168.10.205:7007 master - 0 1458560717276 7 connected 0-265 5461-5727 10923-11188 9db0386330f3d66d0c7cac48dbf2dda1972c96c4 192.168.10.205:7001 master - 0 1458560717276 1 connected 266-5460 5d1ccd0b651b135bbc5e91976aff91ce3e33b0b6 192.168.10.205:7002 master - 0 1458560716267 2 connected 5728-10922 840e13e7cef0db82172fab8c50180088055ada60 192.168.10.205:7006 slave 8f2f43ef9008f299786b3f02446a0ac0d20dde35 0 1458560717780 3 connected
