redis proxy for ip change
更新日期:
redis 当master重启后，则docker ip 变化，slave就无法主从同步。利用代理模式可以缓解这个。
由于每次run、restart 容器后，容器的ip就会变化。因此 redis的 slaveOf=< old master ip> 就会引起主从不同步的问题。
所以，这里引入代理模式。可以缓解这个问题，思路是这样的，在不稳定的机器上部署代理。本质是这样的：master->proxy<-slave
因此，slave永远获取的是proxy的ip，而master ip change会被proxy监听到，对slave 透明。
步骤
启动master
1 | docker run --name redis-master -v /root/app/workspace/redis/data:/data -d --expose 6379 redis redis-server --appendonly yes |
启动代理
利用 cpuguy83/docker-grand-ambassador
1 | docker run -d -v /var/run/docker.sock:/var/run/docker.sock --name redis_ambassador cpuguy83/docker-grand-ambassador -name redis-master |
构建slave
还是利用上一篇Blog的Dockerfile，但这次slave启动的时候link的是proxy
1 | [root@yuanxiaolong redis]# docker build -t yuanxiaolong/redis-slave . [root@yuanxiaolong redis]# docker run -d -P --name=redis_slave --link=redis_ambassador:redis_ambassador yuanxiaolong/redis-slave cbaeabd5d49f87660d4b53ae812f2ea04ba21cfe54b304e37d478137f6f5cb88 [root@yuanxiaolong redis]# docker logs cb redis_ambassador's ip -> 172.17.0.76 [1] 05 Nov 09:58:31.666 # You requested maxclients of 10000 requiring at least 10032 max file descriptors. [1] 05 Nov 09:58:31.666 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted. [1] 05 Nov 09:58:31.667 # Current maximum open files is 1024. maxclients has been reduced to 4064 to compensate for low ulimit. If you need higher maxclients increase 'ulimit -n'. _._ _.-``__ ''-._ _.-`` `. `_. ''-._ Redis 2.8.17 (00000000/0) 64 bit .-`` .-```. ```\/ _.,_ ''-._ ( ' , .-` | `, ) Running in stand alone mode |`-._`-...-` __...-.``-._|'` _.-'| Port: 6379 | `-._ `._ / _.-' | PID: 1 `-._ `-._ `-./ _.-' _.-' |`-._`-._ `-.__.-' _.-'_.-'| | `-._`-._ _.-'_.-' | http://redis.io `-._ `-._`-.__.-'_.-' _.-' |`-._`-._ `-.__.-' _.-'_.-'| | `-._`-._ _.-'_.-' | `-._ `-._`-.__.-'_.-' _.-' `-._ `-.__.-' _.-' `-._ _.-' `-.__.-' [1] 05 Nov 09:58:31.668 # Server started, Redis version 2.8.17 [1] 05 Nov 09:58:31.668 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect. [1] 05 Nov 09:58:31.668 * The server is now ready to accept connections on port 6379 [1] 05 Nov 09:58:31.668 * Connecting to MASTER 172.17.0.76:6379 [1] 05 Nov 09:58:31.668 * MASTER <-> SLAVE sync started [1] 05 Nov 09:58:31.670 * Non blocking connect for SYNC fired the event. [1] 05 Nov 09:58:31.671 * Master replied to PING, replication can continue... [1] 05 Nov 09:58:31.671 * Partial resynchronization not possible (no cached master) [1] 05 Nov 09:58:31.673 * Full resync from master: 0694696a66ef4e6dce92dbbf66c03cb46cc44922:1 [1] 05 Nov 09:58:31.689 * MASTER <-> SLAVE sync: receiving 48 bytes from master [1] 05 Nov 09:58:31.689 * MASTER <-> SLAVE sync: Flushing old data [1] 05 Nov 09:58:31.689 * MASTER <-> SLAVE sync: Loading DB in memory [1] 05 Nov 09:58:31.689 * MASTER <-> SLAVE sync: Finished with success |
验证
验证一下现在的数据，现在的ip，重启，重启后的ip
1 | [root@yuanxiaolong redis]# sh ~/docker-enter.sh cb root@cbaeabd5d49f:~# redis-cli 127.0.0.1:6379> keys * 1) "hello" 2) "yuan" [root@yuanxiaolong redis]# docker-ip 26 172.17.0.97 [root@yuanxiaolong redis]# docker restart 26 26 [root@yuanxiaolong redis]# docker-ip 26 172.17.0.106 |
重启master
重启master后，给master放置数据
1 | [root@yuanxiaolong redis]# sh ~/docker-enter.sh 26 root@26d8e94cc2b1:~# redis-cli keys * 1) "yuan" 2) "hello" root@26d8e94cc2b1:~# redis-cli 127.0.0.1:6379> set good job OK 127.0.0.1:6379> keys * 1) "good" 2) "yuan" 3) "hello" |
查看slave
进入slave，发现主从已同步。（之前不引用代理，重启master，slave里是没有新数据的，而且slave的log是找不到old master ip的）
1 | [root@yuanxiaolong redis]# sh ~/docker-enter.sh cb root@cbaeabd5d49f:~# redis-cli 127.0.0.1:6379> keys * 1) "hello" 2) "good" 3) "yuan" 127.0.0.1:6379> get good "job" |
我们看一下 proxy 的日志，就能发现 master重启后，proxy监听并代理的新的ip。（我之前重启了master 2次，所以ip从 75 -> 97，再 97 -> 106 ）
1 | [root@yuanxiaolong redis]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES cbaeabd5d49f yuanxiaolong/redis-slave:latest /entrypoint.sh ./sta 12 minutes ago Up 12 minutes 0.0.0.0:49168->6379/tcp redis_slave fb86c9b5d007 cpuguy83/docker-grand-ambassador:latest /usr/bin/grand-ambas About an hour ago Up About an hour redis_ambassador,redis_slave/redis_ambassador 26d8e94cc2b1 redis:latest /entrypoint.sh redis About an hour ago Up 10 minutes 6379/tcp redis-master [root@yuanxiaolong redis]# docker logs fb time="2014-11-05T08:17:39Z" level="info" msg="Initializing proxy" time="2014-11-05T08:17:39Z" level="info" msg="Proxying 172.17.0.75:6379/tcp" time="2014-11-05T08:17:39Z" level="info" msg="Handling Events for: 26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db: /redis-master" time="2014-11-05T09:03:10Z" level="info" msg="Received event: &{26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db stop}" time="2014-11-05T09:03:10Z" level="info" msg="Stopping proxy on tcp/[::]:6379 for tcp/172.17.0.75:6379 (accept tcp [::]:6379: use of closed network connection)" time="2014-11-05T09:03:10Z" level="info" msg="Received event: &{26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db die}" time="2014-11-05T09:03:44Z" level="info" msg="Received event: &{26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db start}" time="2014-11-05T09:03:44Z" level="info" msg="Closing old servers" time="2014-11-05T09:03:44Z" level="info" msg="Servers closed" time="2014-11-05T09:03:44Z" level="info" msg="Proxying 172.17.0.97:6379/tcp" time="2014-11-05T10:00:13Z" level="info" msg="Received event: &{26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db die}" time="2014-11-05T10:00:13Z" level="info" msg="Received event: &{26d8e94cc2b1c39ac4df7a0e7c8bc45abc4af01da6a684093b9070c2e7ecc6db restart}" time="2014-11-05T10:00:13Z" level="info" msg="Closing old servers" time="2014-11-05T10:00:13Z" level="info" msg="Stopping proxy on tcp/[::]:6379 for tcp/172.17.0.97:6379 (accept tcp [::]:6379: use of closed network connection)" time="2014-11-05T10:00:13Z" level="info" msg="Servers closed" time="2014-11-05T10:00:13Z" level="info" msg="Proxying 172.17.0.106:6379/tcp" time="2014-11-05T10:01:15Z" level="info" msg="Can't forward traffic to backend tcp/172.17.0.97:6379: dial tcp 172.17.0.97:6379: connection timed out\n" |
