Redis4.0数据库(二):Redis4.0之持久化存储(下)
十,Redis的RDB存储方式
10.1 redis的运行方式说明
redis如果提供缓存服务,可以关闭所有持久化存储,如此一来redis重启后所有数据会丢失
开启rdb或aof持久化存储,能把redis中的数据持久化到磁盘中。
rdb和aof对性能都有影响,所以建议持久化的操作在从库上进行
10.2 redis rdb存储方式,使用save配置开启rdb存储或者关闭rdb存储
#与rdb相关的配置文件信息dir /data/redis/ #dir为rdb存储的路径dbfilename dump.rdb #rdb存储文件的名字save 60 10000 #60s改变10000key,触发rdb存储save 300 10 #300s改变10个key,触发rdb存储save 900 1 #900s改变1个key触发rdb存储rdbcompression no #rdb压缩最好关闭,影响cpu
10.3 设置开启或者关闭rdb存储
提示:默认情况下rdb持久化存储是开启的
[root@Redis01 ~]# redis-cli config set save "" #关闭rdb存储OK[root@Redis01 ~]# redis-cli config rewrite #配置保存OK[root@Redis01 ~]# redis-cli config set save "180 1 120 10 60 10000" #开启rdbOK[root@Redis01 ~]# redis-cli config rewrite #配置保存OK
10.4 进行数据写入,观察rdb存储日志
#输入1万条数据for line in `seq -w 10000`;do redis-cli set key_${line} value1_${line};done
#查看日志信息51876:M 11 Aug 09:36:24.049 * 10000 changes in 60 seconds. Saving... #发生了1万条数据改变60秒内,触发rdb存储51876:M 11 Aug 09:36:24.050 * Background saving started by pid 8085580855:C 11 Aug 09:36:24.058 * DB saved on disk80855:C 11 Aug 09:36:24.059 * RDB: 0 MB of memory used by copy-on-write51876:M 11 Aug 09:36:24.152 * Background saving terminated with success
10.5 redis提供的bgsave命令能够立刻触发rdb存储,观察存储日志
[root@Redis01 ~]# redis-cli save #会阻塞前端客户数据输入OK[root@Redis01 ~]# redis-cli bgsave #后台启动新进程进行rdb存储Background saving started
#查看日志51876:M 11 Aug 09:45:15.100 * DB saved on disk #save触发的日志信息51876:M 11 Aug 09:45:19.641 * Background saving started by pid 81313 #bgsave触发的信息81313:C 11 Aug 09:45:19.646 * DB saved on disk #bgsave触发的信息81313:C 11 Aug 09:45:19.646 * RDB: 0 MB of memory used by copy-on-write #bgsave触发的信息51876:M 11 Aug 09:45:19.743 * Background saving terminated with success #bgsave触发的信息
十一,Redis的AOF存储方式
redis的appendonly(aof)持久化存储会把用户每次的操作都记录到文件中(类似mysqlbinlog)
11.1 动态开启或者关闭aof
[root@Redis01 ~]# redis-cli config set appendonly yes #开启OK[root@Redis01 ~]# redis-cli config rewriteOK[root@Redis01 ~]# redis-cli config set appendonly no #关闭OK[root@Redis01 ~]# redis-cli config rewriteOK
11.2 写入数据,观察aof。多次运行,aof文件不断增大,rdb文件大小不变
#查看aof和rdb文件大小[root@Redis01 redis]# du -sh appendonly.aof512K appendonly.aof[root@Redis01 redis]# du -sh dump.rdb260K dump.rdb#写入数据[root@Redis01 ~]# for line in `seq -w 100`;do redis-cli set key_${line} value_${line};done#查看aof和rdb文件大小[root@Redis01 redis]# du -sh appendonly.aof1.5M appendonly.aof[root@Redis01 redis]# du -sh dump.rdb260K dump.rdb
11.3 重写aof文件,整理相同的key,写入最后的有效值
BGREWRITEAOF
执行一个AOF文件重写操作。重写会创建一个当前AOF文件的体积优化版本
即使BGREWRITEAOF执行失败,也不会有任何数据丢失,因为旧的AOF文件在BGREWRITEAOF成功之前不会被修改。
重写操作只会在没有其他持久化工作在后台执行时被触发。
从Redis2.4开始,AOF重写由Redis自行触发,BGREWRITEAOF仅仅用于手动触发重写操作。
#清空aof文件[root@Redis01 redis]# >appendonly.aof[root@Redis01 redis]# lsappendonly.aof dump.rdb redis.log redis.pid[root@Redis01 redis]# du -sh appendonly.aof0 appendonly.aof[root@Redis01 ~]# redis-cli bgrewriteaof #手动触发AOF重写Background append only file rewriting started[root@Redis01 redis]# du -sh appendonly.aof #redis里所有数据被重写入aof512K appendonly.aof#清空aof文件[root@Redis01 redis]# >appendonly.aof[root@Redis01 redis]# du -sh appendonly.aof0 appendonly.aof[root@Redis01 redis]# redis-cli set yunjisuan benetOK[root@Redis01 redis]# du -sh appendonly.aof4.0K appendonly.aof[root@Redis01 redis]# cat appendonly.aof*2$6SELECT #select 0 表示切换到db0$10*3$3set #执行set yunjisuan benet$9yunjisuan$5benet[root@Redis01 redis]# redis-cli del yunjisuan benet(integer) 1[root@Redis01 redis]# cat appendonly.aof*2$6SELECT$10*3$3set$9yunjisuan$5benet*3$3del #执行del yunjisuan benet$9yunjisuan$5benet
我们发现虽然我们向redis添加了一个key,又删除了这个key。redis数据库从本质上来说并没有新增任何数据。但是aof文件仍旧把操作都给记录了。这样就会导致aof文件最终会非常大。所以aof文件的优化,就是让aof文件进行重写,只记录数据的增量部分。如此aof文件就小很多了。
11.4 aof配置自动rewrite机制
#在默认配置文件里,默认存在auto-aof-rewrite-percentage 100 #默认100%,也就是aof增加一倍后考虑rewrite,两个条件要同时满足auto-aof-rewrite-min-size 64mb #默认64mb,也就是aof达到64M后考虑rewirte,两个条件要同时满足#获取aof-rewrite配置[root@Redis01 redis]# redis-cli config get auto-aof-rewrite*1) "auto-aof-rewrite-percentage"2) "100"3) "auto-aof-rewrite-min-size"4) "67108864" #64MB(单位字节)#进行aof自动重写测试[root@Redis01 redis]# redis-cli config set auto-aof-rewrite-min-size 100000[root@Redis01 redis]# redis-cli config get auto-aof-rewrite*1) "auto-aof-rewrite-percentage"2) "100"3) "auto-aof-rewrite-min-size"4) "100000"[root@Redis01 redis]# redis-cli config rewriteOK[root@Redis01 redis]# > appendonly.aof[root@Redis01 redis]# du -sh appendonly.aof0 appendonly.aof[root@Redis01 ~]# for line in `seq -w 1000`;do redis-cli set key2_${line} value2_${line};done[root@Redis01 redis]# du -sh appendonly.aof48K appendonly.aof[root@Redis01 ~]# for line in `seq -w 1000`;do redis-cli del key2_${line} value2_${line};done[root@Redis01 redis]# du -sh appendonly.aof128K appendonly.aof[root@Redis01 redis]# du -sh appendonly.aof128K appendonly.aof[root@Redis01 redis]# du -sh appendonly.aof92K appendonly.aof #自动触发了aof重写机制
十二,Redis最大内存设置和删除算法
redis-cli flushall#手动清空redis里所有数据
12.1 redis的键设置有效期,过期自动删除
[root@Redis01 ~]# redis-cli set name yunjisuanOK[root@Redis01 ~]# redis-cli ttl name(integer) -1 #-1代表key永久有效[root@Redis01 ~]# redis-cli expire name 10 #设定key 10s有效(integer) 1[root@Redis01 ~]# redis-cli ttl name #查看key存活剩余时间(integer) 8[root@Redis01 ~]# redis-cli ttl name(integer) 7[root@Redis01 ~]# redis-cli ttl name(integer) 6[root@Redis01 ~]# redis-cli ttl name(integer) 6[root@Redis01 ~]# redis-cli ttl name(integer) 5[root@Redis01 ~]# redis-cli ttl name(integer) 4[root@Redis01 ~]# redis-cli ttl name(integer) 4[root@Redis01 ~]# redis-cli ttl name(integer) 3[root@Redis01 ~]# redis-cli ttl name(integer) 2[root@Redis01 ~]# redis-cli ttl name(integer) 1[root@Redis01 ~]# redis-cli ttl name(integer) 0[root@Redis01 ~]# redis-cli ttl name(integer) -2[root@Redis01 ~]# redis-cli get name #key已经被过期清除了(nil)
12.2 查看设置最大内存
#查看和设定最大内存限制[root@Redis01 ~]# redis-cli config get maxmemory1) "maxmemory"2) "0" #默认对内存无限制[root@Redis01 ~]# redis-cli config set maxmemory 1M #限制1MOK[root@Redis01 ~]# redis-cli config get maxmemory1) "maxmemory"2) "1000000"
12.3 可选择的删除算法
- volatile-lru:
- 使用LRU算法删除键(key需要设置过期时间)
- volatile-random:
- 随机删除键(key需要设置过期时间)
- volatile-ttl:
- 删除ttl最小的键(key需要设置过期时间)
- allkeys-lru:
- 使用LRU算法删除键(所有key)
- allkeys-random:
- 随机删除键(所有key)
- noeviction:
- 不进行任何的操作,只返回错误,默认
[root@Redis01 ~]# redis-cli config get maxmemory-policy #内存清理算法1) "maxmemory-policy"2) "noeviction" #默认noeviction
12.4 模拟超过内存
[root@Redis01 ~]# for line in `seq -w 10000`;do redis-cli set key_${line} value_${line};done[root@Redis01 ~]# redis-cli set name benet(error) OOM command not allowed when used memory > 'maxmemory'.[root@Redis01 ~]# redis-cli127.0.0.1:6379> set name benet(error) OOM command not allowed when used memory > 'maxmemory'.
测试会发现报错
(error) OOM command not allowed when used memory > 'maxmemory'.
12.5 设置删除算法
#将删除算法设置为volatile-lru[root@Redis01 ~]# redis-cli config get maxmemory-policy1) "maxmemory-policy"2) "noeviction"[root@Redis01 ~]# redis-cli config set maxmemory-policy volatile-lruOK[root@Redis01 ~]# redis-cli config get maxmemory-policy1) "maxmemory-policy"2) "volatile-lru"[root@Redis01 ~]# redis-cli config rewriteOK#算法测试[root@Redis01 ~]# redis-cli get key_00111"value_00111"[root@Redis01 ~]# redis-cli expire key_00111 3600(integer) 1[root@Redis01 ~]# redis-cli ttl key_00111(integer) -2[root@Redis01 ~]# redis-cli get key_00111(nil)说明:由上述测试可以发现volatile-lru算法当内存到了最大值以后,会优先删除有过期时间的key。
十三,Redis禁用屏蔽危险命令
13.1 redis禁用的命令
FLUSHALL和FLUSHDB会清除redis的数据,比较危险
KEYS在键过多的时候使用会阻塞业务请求
13.2 redis禁用危险命令配置代码如下(写入配置文件即可,此配置无法平滑更新)
rename-command FLUSHALL "" #将命令改名成空rename-command FLUSHDB "" #将命令改名成空rename-command KEYS "" #将命令改名成空
将配置加入redis.conf配置文件
[root@Redis01 ~]# echo 'rename-command FLUSHALL ""' >> /usr/local/redis/conf/redis.conf[root@Redis01 ~]# echo 'rename-command FLUSHDB ""' >> /usr/local/redis/conf/redis.conf[root@Redis01 ~]# echo 'rename-command KEYS ""' >> /usr/local/redis/conf/redis.conf[root@Redis01 ~]# tail -3 /usr/local/redis/conf/redis.confrename-command FLUSHALL ""rename-command FLUSHDB ""rename-command KEYS ""
13.3 登陆redis,运行禁止命令进行测试
#重启redis-server[root@Redis01 ~]# redis-cli shutdown[root@Redis01 ~]# redis-server /usr/local/redis/conf/redis.conf#测试被屏蔽的危险命令[root@Redis01 ~]# redis-cli flushall(error) ERR unknown command `flushall`, with args beginning with:[root@Redis01 ~]# redis-cli flushdb(error) ERR unknown command `flushdb`, with args beginning with:[root@Redis01 ~]# redis-cli127.0.0.1:6379> keys *(error) ERR unknown command `keys`, with args beginning with: `*`,
十四,Redis主从服务器环境的搭建
| 主机名 | IP | 用途 |
|---|---|---|
| redis01 | 192.168.200.165 | redis-master |
| redis02 | 192.168.200.164 | redis-slaveA |
| redis03 | 192.168.200.163 | redis-slaveB |
14.1 环境要求与redis基础编译部署调优
#操作系统环境要求[root@Redis01 ~]# cat /etc/redhat-releaseCentOS Linux release 7.5.1804 (Core)[root@Redis01 ~]# uname -r3.10.0-862.3.3.el7.x86_64[root@Redis01 ~]# systemctl stop firewalld[root@Redis01 ~]# systemctl disable firewalld[root@Redis01 ~]# setenforce 0setenforce: SELinux is disabled[root@Redis01 ~]# sestatusSELinux status: disabled#三台redis都进行如下编译过程[root@Redis01 ~]# yum -y install wget gcc gcc-c++ make tar openssl openssl-devel cmake[root@Redis01 ~]# tar xf redis-4.0.11.tar.gz -C /usr/src/[root@Redis01 ~]# cd /usr/src/redis-4.0.11/[root@Redis01 redis-4.0.11]# make[root@Redis01 redis-4.0.11]# make MALLOC=jemalloc[root@Redis01 redis-4.0.11]# make PREFIX=/usr/local/redis install[root@Redis01 redis-4.0.11]# cd /usr/local/redis/[root@Redis01 redis]# lsbin[root@Redis01 redis]# mkdir -p /usr/local/redis/conf[root@Redis01 redis]# cp /usr/src/redis-4.0.11/redis.conf /usr/local/redis/conf/[root@Redis01 redis]# cp /usr/src/redis-4.0.11/sentinel.conf /usr/local/redis/conf/[root@Redis01 src]# ln -s /usr/local/redis/bin/* /usr/local/bin/[root@Redis01 src]# which redis-server/usr/local/bin/redis-server#三台都进行配置文件优化和简单的基础调优[root@Redis01 redis]# pwd/usr/local/redis[root@Redis01 redis]# cp conf/redis.conf{,.bak}[root@Redis01 redis]# egrep -v "^$|^#" conf/redis.conf.bak > conf/redis.conf[root@Redis01 redis]# mkdir -p /data/redis/ #创建redis数据目录#修改配置文件[root@Redis01 redis]# cat -n conf/redis.conf | sed -n '1p;3p;4p;7p;9p;11p;21p'1 bind 127.0.0.13 port 63794 tcp-backlog 5117 daemonize no9 pidfile /var/run/redis_6379.pid11 logfile ""21 dir ./#修改成以下设置[root@Redis01 redis]# cat -n conf/redis.conf | sed -n '1p;3p;4p;7p;9p;11p'1 bind 0.0.0.0 #监听地址3 port 6379 #监听端口4 tcp-backlog 1024 #tcp连接数7 daemonize yes #是否后台启动9 pidfile /data/redis/redis.pid #pid存放目录11 logfile "/data/redis/redis.log" #日志存放目录21 dir /data/redis/ #工作目录#进行基础调优设置echo "* - nofile 10240" >> /etc/security/limits.confecho "net.core.somaxconn = 10240" >> /etc/sysctl.confecho "vm.overcommit_memory = 1" >> /etc/sysctl.confsysctl -pecho never > /sys/kernel/mm/transparent_hugepage/enabledecho never > /sys/kernel/mm/transparent_hugepage/defragecho 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' >> /etc/rc.localecho 'echo never > /sys/kernel/mm/transparent_hugepage/defrag' >> /etc/rc.local#三台的redis-server都启动[root@Redis01 ~]# redis-server /usr/local/redis/conf/redis.conf[root@Redis01 ~]# netstat -antup | grep redistcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 24733/redis-server[root@Redis02 ~]# redis-server /usr/local/redis/conf/redis.conf[root@Redis02 ~]# netstat -antup | grep redistcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 18289/redis-server[root@Redis03 ~]# redis-server /usr/local/redis/conf/redis.conf[root@Redis03 ~]# netstat -antup | grep redistcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 18300/redis-server
14.2 redis主从同步服务器搭建
redis的主从同步,不用修改master任何配置
只需要在redis-slave上指定master的IP地址即可
#先启动redis-master,然后再在两个redis-slave上都进行如下操作[root@Redis02 ~]# redis-cli shutdown[root@Redis02 ~]# echo "SLAVEOF 192.168.200.165 6379" >> /usr/local/redis/conf/redis.conf[root@Redis02 ~]# > /data/redis/redis.log[root@Redis02 ~]# redis-server /usr/local/redis/conf/redis.conf[root@Redis02 ~]# netstat -antup | grep redistcp 0 0 0.0.0.0:6379 0.0.0.0:* LISTEN 18342/redis-servertcp 0 0 192.168.200.164:37373 192.168.200.165:6379 ESTABLISHED 18342/redis-server
14.3 主从同步日志分析(全量同步)
#查看redis-slave同步日志[root@Redis02 ~]# cat /data/redis/redis.log18341:C 11 Aug 13:56:54.895 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo18341:C 11 Aug 13:56:54.895 # Redis version=4.0.11, bits=64, commit=00000000, modified=0, pid=18341, just started18341:C 11 Aug 13:56:54.895 # Configuration loaded_.__.-``__ ''-.__.-`` `. `_. ''-._ Redis 4.0.11 (00000000/0) 64 bit.-`` .-```. ```\/ _.,_ ''-._( ' , .-` | `, ) Running in standalone mode|`-._`-...-` __...-.``-._|'` _.-'| Port: 6379| `-._ `._ / _.-' | PID: 18342`-._ `-._ `-./ _.-' _.-'|`-._`-._ `-.__.-' _.-'_.-'|| `-._`-._ _.-'_.-' | http://redis.io`-._ `-._`-.__.-'_.-' _.-'|`-._`-._ `-.__.-' _.-'_.-'|| `-._`-._ _.-'_.-' |`-._ `-._`-.__.-'_.-' _.-'`-._ `-.__.-' _.-'`-._ _.-'`-.__.-'18342:S 11 Aug 13:56:54.897 # Server initialized #服务器初始化18342:S 11 Aug 13:56:54.897 * DB loaded from disk: 0.000 seconds #数据从磁盘加载0秒18342:S 11 Aug 13:56:54.897 * Ready to accept connections #准备接受连接18342:S 11 Aug 13:56:54.897 * Connecting to MASTER 192.168.200.165:6379 #链接到主192.168.200.165:637918342:S 11 Aug 13:56:54.897 * MASTER <-> SLAVE sync started #主从同步开始18342:S 11 Aug 13:56:54.897 * Non blocking connect for SYNC fired the event. #非阻塞同步连接触发事件18342:S 11 Aug 13:56:54.898 * Master replied to PING, replication can continue... #主应答,复制可以继续18342:S 11 Aug 13:56:54.898 * Partial resynchronization not possible (no cached master) #部分同步不能(本机无缓存的主文件)18342:S 11 Aug 13:56:54.899 * Full resync from master: e3adc85bd644e66bd1ee17b49c25e5e0491084d5:0 #进行全同步18342:S 11 Aug 13:56:54.917 * MASTER <-> SLAVE sync: receiving 43606 bytes from master #从主接收43606字节18342:S 11 Aug 13:56:54.917 * MASTER <-> SLAVE sync: Flushing old data #刷新旧数据18342:S 11 Aug 13:56:54.917 * MASTER <-> SLAVE sync: Loading DB in memory #加载数据到内存18342:S 11 Aug 13:56:54.918 * MASTER <-> SLAVE sync: Finished with success #同步完成#查看redis-master同步日志[root@Redis01 ~]# cat /data/redis/redis.log#从192.168.200.163:6379请求同步26003:M 11 Aug 14:14:55.342 * Slave 192.168.200.163:6379 asks for synchronization#从192.168.200.163:6379请求完整的重新同步26003:M 11 Aug 14:14:55.342 * Full resync requested by slave 192.168.200.163:6379#master启动bgsave与目标的磁盘进行同步26003:M 11 Aug 14:14:55.342 * Starting BGSAVE for SYNC with target: disk#后台保存rdb的进程的pid号为2612826003:M 11 Aug 14:14:55.342 * Background saving started by pid 26128#rdb文件已经保存到了磁盘26128:C 11 Aug 14:14:55.344 * DB saved on disk#rdb写时复制使用了0MB的内存26128:C 11 Aug 14:14:55.344 * RDB: 0 MB of memory used by copy-on-write#后台保存成功26003:M 11 Aug 14:14:55.414 * Background saving terminated with success#与从192.168.200.163:6379同步成功26003:M 11 Aug 14:14:55.415 * Synchronization with slave 192.168.200.163:6379 succeeded
14.4 主从同步日志分析(部分同步)
#清空master日志[root@Redis01 ~]# > /data/redis/redis.log#清空slave日志,并shutdown[root@Redis02 ~]# > /data/redis/redis.log[root@Redis02 ~]# redis-cli shutdown#启动slave[root@Redis02 ~]# redis-server /usr/local/redis/conf/redis.conf#查看redis-slave日志[root@Redis02 ~]# cat /data/redis/redis.log18342:S 11 Aug 14:23:27.678 # User requested shutdown...18342:S 11 Aug 14:23:27.678 * Saving the final RDB snapshot before exiting.18342:S 11 Aug 14:23:27.681 * DB saved on disk18342:S 11 Aug 14:23:27.681 * Removing the pid file.18342:S 11 Aug 14:23:27.681 # Redis is now ready to exit, bye bye...18417:C 11 Aug 14:24:41.432 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo18417:C 11 Aug 14:24:41.432 # Redis version=4.0.11, bits=64, commit=00000000, modified=0, pid=18417, just started18417:C 11 Aug 14:24:41.432 # Configuration loaded_.__.-``__ ''-.__.-`` `. `_. ''-._ Redis 4.0.11 (00000000/0) 64 bit.-`` .-```. ```\/ _.,_ ''-._( ' , .-` | `, ) Running in standalone mode|`-._`-...-` __...-.``-._|'` _.-'| Port: 6379| `-._ `._ / _.-' | PID: 18418`-._ `-._ `-./ _.-' _.-'|`-._`-._ `-.__.-' _.-'_.-'|| `-._`-._ _.-'_.-' | http://redis.io`-._ `-._`-.__.-'_.-' _.-'|`-._`-._ `-.__.-' _.-'_.-'|| `-._`-._ _.-'_.-' |`-._ `-._`-.__.-'_.-' _.-'`-._ `-.__.-' _.-'`-._ _.-'`-.__.-'#服务器初始化18418:S 11 Aug 14:24:41.434 # Server initialized#从磁盘加载旧数据用时0.001秒18418:S 11 Aug 14:24:41.434 * DB loaded from disk: 0.001 seconds#由于之前是一个从库,利用主的参数合成一个主的缓存,这样就可以和主仅仅进行一部分的数据同步18418:S 11 Aug 14:24:41.434 * Before turning into a slave, using my master parameters to synthesize a cached master: I may be able to synchronize with the new master with just a partial transfer.#准备接受连接18418:S 11 Aug 14:24:41.434 * Ready to accept connections#连接到master192.168.200.165:637918418:S 11 Aug 14:24:41.435 * Connecting to MASTER 192.168.200.165:6379#主从同步开始18418:S 11 Aug 14:24:41.435 * MASTER <-> SLAVE sync started#非阻塞同步连接触发事件18418:S 11 Aug 14:24:41.435 * Non blocking connect for SYNC fired the event.#master应答,复制可以继续18418:S 11 Aug 14:24:41.435 * Master replied to PING, replication can continue...#尝试进行部分同步(要求646f44ea31d2b057e919e08493f94e97e92007f2:911)18418:S 11 Aug 14:24:41.435 * Trying a partial resynchronization (request 646f44ea31d2b057e919e08493f94e97e92007f2:911).#成功进行部分同步18418:S 11 Aug 14:24:41.436 * Successful partial resynchronization with master.#master应答接受一个部分同步的请求18418:S 11 Aug 14:24:41.436 * MASTER <-> SLAVE sync: Master accepted a Partial Resynchronization.#查看redis-master日志[root@Redis01 ~]# cat /data/redis/redis.log#一个从库192.168.200.164:6379请求进行同步26003:M 11 Aug 14:24:41.424 * Slave 192.168.200.164:6379 asks for synchronization#一个部分同步的请求来自192.168.200.164:6379,master已经接受请求,从偏移量为911处开始发送98字节的剩余数据26003:M 11 Aug 14:24:41.424 * Partial resynchronization request from 192.168.200.164:6379 accepted. Sending 98 bytes of backlog starting from offset 911.
14.5 主从同步的停止
#清空从库日志[root@Redis02 ~]# > /data/redis/redis.log#停止从库主从同步(只能在从库上执行)[root@Redis02 ~]# redis-cli slaveof no oneOK#查看日志[root@Redis02 ~]# cat /data/redis/redis.log#将第二次复制的ID设置为646f44ea31d2b057e919e08493f94e97e92007f2,有效偏移量:3571。新的复制ID为efb9d2d393bb0bb4570a2f3144e7b2fbfc60b89218418:M 11 Aug 14:55:15.723 # Setting secondary replication ID to 646f44ea31d2b057e919e08493f94e97e92007f2, valid up to offset: 3571. New replication ID is efb9d2d393bb0bb4570a2f3144e7b2fbfc60b892#与主库失去联系18418:M 11 Aug 14:55:15.723 # Connection with master lost.#主从状态缓存断开18418:M 11 Aug 14:55:15.723 * Caching the disconnected master state.#丢弃之前缓存的主的状态18418:M 11 Aug 14:55:15.723 * Discarding previously cached master state.#主模式启用18418:M 11 Aug 14:55:15.723 * MASTER MODE enabled (user request from 'id=4 addr=127.0.0.1:39500 fd=8 name= age=0 idle=0 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=32768 obl=0 oll=0 omem=0 events=r cmd=slaveof')#清空redis日志并恢复从库主从同步[root@Redis02 ~]# > /data/redis/redis.log[root@Redis02 ~]# redis-cli slaveof 192.168.200.165 6379OK#查看slave日志[root@Redis02 ~]# cat /data/redis/redis.log18418:S 11 Aug 15:02:40.330 * Before turning into a slave, using my master parameters to synthesize a cached master: I may be able to synchronize with the new master with just a partial transfer.18418:S 11 Aug 15:02:40.330 * SLAVE OF 192.168.200.165:6379 enabled (user request from 'id=5 addr=127.0.0.1:39502 fd=7 name= age=0 idle=0 flags=N db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=32768 obl=0 oll=0 omem=0 events=r cmd=slaveof')18418:S 11 Aug 15:02:40.928 * Connecting to MASTER 192.168.200.165:637918418:S 11 Aug 15:02:40.928 * MASTER <-> SLAVE sync started18418:S 11 Aug 15:02:40.928 * Non blocking connect for SYNC fired the event.18418:S 11 Aug 15:02:40.929 * Master replied to PING, replication can continue...18418:S 11 Aug 15:02:40.929 * Trying a partial resynchronization (request efb9d2d393bb0bb4570a2f3144e7b2fbfc60b892:3571).18418:S 11 Aug 15:02:40.929 * Full resync from master: 646f44ea31d2b057e919e08493f94e97e92007f2:418618418:S 11 Aug 15:02:40.929 * Discarding previously cached master state.18418:S 11 Aug 15:02:40.967 * MASTER <-> SLAVE sync: receiving 43607 bytes from master18418:S 11 Aug 15:02:40.968 * MASTER <-> SLAVE sync: Flushing old data18418:S 11 Aug 15:02:40.968 * MASTER <-> SLAVE sync: Loading DB in memory18418:S 11 Aug 15:02:40.970 * MASTER <-> SLAVE sync: Finished with success
14.6 加密的主从同步
(1)为redis-master平滑设置连接密码
[root@Redis01 ~]# redis-cli config get requirepass1) "requirepass"2) ""[root@Redis01 ~]# redis-cli config set requirepass 'yunjisuan'OK[root@Redis01 ~]# redis-cli config get requirepass(error) NOAUTH Authentication required.[root@Redis01 ~]# redis-cli -a yunjisuan config get requirepassWarning: Using a password with '-a' option on the command line interface may not be safe.1) "requirepass"2) "yunjisuan"[root@Redis01 ~]# redis-cli -a yunjisuan config rewriteWarning: Using a password with '-a' option on the command line interface may not be safe.OK#查看从库日志信息[root@Redis02 ~]# cat /data/redis/redis.log#主从同步需要进行端口验证请求18418:S 11 Aug 15:08:40.440 * (Non critical) Master does not understand REPLCONF listening-port: -NOAUTH Authentication required.18418:S 11 Aug 15:08:40.440 * (Non critical) Master does notunderstand REPLCONF capa: -NOAUTH Authentication required.#部分同步不能,没有主的缓存18418:S 11 Aug 15:08:40.440 * Partial resynchronization not possible (no cached master)#从主发来的意外回复:需要身份验证18418:S 11 Aug 15:08:40.441 # Unexpected reply to PSYNC from master: -NOAUTH Authentication required.#进行同步重试18418:S 11 Aug 15:08:40.441 * Retrying with SYNC...#主从复制终止:需要身份验证18418:S 11 Aug 15:08:40.441 # MASTER aborted replication with an error: NOAUTH Authentication required.
(2)为从库提供主从同步密码验证
#从服务器需要设置主从同步的认证密码[root@Redis02 ~]# redis-cli config get masterauth1) "masterauth"2) ""[root@Redis02 ~]# redis-cli config set masterauth "yunjisuan"OK[root@Redis02 ~]# redis-cli config get masterauth1) "masterauth"2) "yunjisuan"[root@Redis02 ~]# redis-cli config rewriteOK[root@Redis02 ~]# tail -1 /usr/local/redis/conf/redis.confmasterauth "yunjisuan"#查看从服务器日志[root@Redis02 ~]# cat /data/redis/redis.log18418:S 11 Aug 15:14:07.854 * Connecting to MASTER 192.168.200.165:637918418:S 11 Aug 15:14:07.854 * MASTER <-> SLAVE sync started18418:S 11 Aug 15:14:07.855 * Non blocking connect for SYNC fired the event.18418:S 11 Aug 15:14:07.856 * Master replied to PING, replication can continue...18418:S 11 Aug 15:14:07.858 * Partial resynchronization not possible (no cached master)18418:S 11 Aug 15:14:07.860 * Full resync from master: 646f44ea31d2b057e919e08493f94e97e92007f2:464818418:S 11 Aug 15:14:07.886 * MASTER <-> SLAVE sync: receiving 43607 bytes from master18418:S 11 Aug 15:14:07.888 * MASTER <-> SLAVE sync: Flushing old data18418:S 11 Aug 15:14:07.889 * MASTER <-> SLAVE sync: Loading DB in memory18418:S 11 Aug 15:14:07.893 * MASTER <-> SLAVE sync: Finished with success18418:S 11 Aug 15:14:18.778 # CONFIG REWRITE executed with success.
十五,使用Python操作Redis单例
15.1 Python安装redis扩展
[root@redis-master ~]# yum -y install epel-release[root@redis-master ~]# yum -y install python2-pip[root@redis-master ~]# pip install redis
15.2 利用python进行redis数据的读写
[root@Redis01 ~]# pythonPython 2.7.5 (default, Apr 11 2018, 07:36:10)[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2Type "help", "copyright", "credits" or "license" for more information.>>> import redis>>> r = redis.Redis(host='127.0.0.1',port=6379,password='yunjisuan',db=0)>>> r.set('key_test','value_test')True>>> value = r.get('key_test')>>> print (value)value_test>>> exit()[root@Redis01 ~]# redis-cli -a yunjisuan get key_testWarning: Using a password with '-a' option on the command line interface may not be safe."value_test"

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