Redis Sentry Mode Principle
Sentinel mode is a special mode. First of all, Redis provides the sentinel command. The sentinel is an independent As a process, it will run independently. The principle is that the sentinel monitors multiple running Redis instances by sending commands and waiting for the Redis server to respond.
Linux - redis sentinel cluster instance
Command arrangement
Official website address: http://redisdoc.com/
redis-cli info #查看redis数据库信息 redis-cli info replication #查看redis的复制授权信息 redis-cli info sentinel #查看redis的哨兵信息
Configuration process
Ideas:
redis master-slave
一Master and two slaves plan
1. Environment preparation, prepare the redis architecture of one master and two slaves
redis-6379.conf
port 6379 daemonize yes logfile "6379.log" dbfilename "dump-6379.rdb" dir "/opt/redis/6379/" redis-6380.conf port 6380 daemonize yes logfile "6380.log" dbfilename "dump-6380.rdb" dir "/opt/redis/6380/" slaveof 127.0.0.1 6379 redis-6381.conf port 6381 daemonize yes logfile "6381.log" dbfilename "dump-6381.rdb" dir "/opt/redis/6381/" slaveof 127.0.0.1 6379
2. Prepare three data folders
mkdir -p /opt/redis/{6379,6380,6381}3. Start three databases respectively
[root@master sbredis]# redis-server redis-6379.conf [root@master sbredis]# redis-server redis-6380.conf [root@master sbredis]# redis-server redis-6381.conf
4. Detect the master-slave status
redis-cli -p 6379 info replication redis-cli -p 6380 info replication redis-cli -p 6381 info replication
5. Prepare three redis sentinels to detect the master-slave status
Prepare the configuration of the three sentinels File
redis-26379.conf
// Sentinel节点的端口 port 26379 dir /var/redis/data/ logfile "26379.log" // 当前Sentinel节点监控 192.168.119.10:6379 这个主节点 // 2代表判断主节点失败至少需要2个Sentinel节点节点同意 // mymaster是主节点的别名 sentinel monitor mymaster 192.168.119.10 6379 2 //每个Sentinel节点都要定期PING命令来判断Redis数据节点和其余Sentinel节点是否可达，如果超过30000毫秒30s且没有回复，则判定不可达 sentinel down-after-milliseconds mymaster 30000 //当Sentinel节点集合对主节点故障判定达成一致时，Sentinel领导者节点会做故障转移操作，选出新的主节点， 原来的从节点会向新的主节点发起复制操作，限制每次向新的主节点发起复制操作的从节点个数为1 sentinel parallel-syncs mymaster 1 //故障转移超时时间为180000毫秒 sentinel failover-timeout mymaster 180000 redis-26380.conf port 7000 daemonize yes dir "/opt/data" logfile "7000.log" dbfilename "dump-7000.rdb" cluster-enabled yes cluster-config-file nodes-7000.conf cluster-require-full-coverage no redis-26381.conf
Three configuration files, only the port is different, quickly generate the configuration file through the command
[root@master sbredis]# sed "s/26379/26380/g" redis-26379.conf > redis-26380.conf [root@master sbredis]# sed "s/26379/26381/g" redis-26379.conf > redis-26381.conf
6. Start three sentinels respectively
[root@master sbredis]# redis-sentinel redis-26379.conf [root@master sbredis]# redis-sentinel redis-26380.conf [root@master sbredis]# redis-sentinel redis-26381.conf
7. Detect the sentinel, master-slave status
redis-cli -p 26379 info sentinel
When you see the following information, you are like me
[root@master sbredis]# redis-cli -p 26379 info sentinel Sentinel sentinel_masters:1 sentinel_tilt:0 sentinel_running_scripts:0 sentinel_scripts_queue_length:0 sentinel_simulate_failure_flags:0 master0:name=s17ms,status=ok,address=127.0.0.1:6379,slaves=2,sentinels=3
8. Test, kill the master redis, and see if it switches automatically
ps -ef|grep redis
kill 进程
..9. Start redis 6379 again to see if it has joined the master-slave cluster
redis-server redis-6379.conf
Recommended tutorial: "Redis Tutorial"
The above is the detailed content of Redis sentry mode principle. For more information, please follow other related articles on the PHP Chinese website!
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