基于Sentinel的Redis高可用方案

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数据存储我们在应用设计过程中非常重要的一部分，无论是关系型数据库，还是 Redis、MongoDB 等非关系型数据库，都有很多的高可用方案，还有一些针对不同业务设计的中间件，使其性能更有特色，更能保证数据存储的稳定和安全。

目前主流的 Redis 的数据存储架构有 Redis 单点，Redis 主从，基于 Sentinel 的 Redis 主备、基于 keepalive 的 redis 主备，以及 Redis 集群 Cluster，还有豌豆荚开源的 Codis 等是目前业内比较流行的解决方案，不同的存储架构，是若干个技术工程师，根据自己公司的业务，踩过 N 次坑，总结出的结果，没有最好的解决方案，只有最适合的解决方案。

在上家公司出，采用了 redis 的主从架构，版本是 2.8，上线一年多，尚未出现过问题，但是潜在的隐患是大家都知道的，主从架构中，当主宕机或者意外情况时，主与从不能平滑切换，将会影响业务，所以这里就是一个定时炸弹，而 Sentinel(哨兵)方案是主从架构的升级版，能够让主从之间自动切换。提高系统稳定性和高可用性。以下是最近自己测试哨兵架构的相关记录。

Sentinel 官方文档：https://redis.io/topics/sentinel

操作系统：CentOS 6.7

redis 版本：3.2.9

主机规划：

序号	Host	Redis Role	Redis Port	Sentinel Port
1	10.1.4.82	slave	6379	26379 26380
2	10.1.4.99	master	6379	26379 26380

由于配置 redis 主从比较简单，所以在这里不会去详细的介绍，想了解如何配置的朋友，请参考以下文章。

http://www.linuxidc.com/Linux/2017-08/146252.htm

2、检验 redis 主从是否正常

登录 redis 的 Master 主节点检查 redis 主从

127.0.0.1:6379> info

127.0.0.1:6379> info
# Server
redis_version:3.2.9
redis_git_sha1:00000000
redis_git_dirty:0
redis_build_id:66cf707c3c51d9f
redis_mode:standalone
os:Linux 2.6.32-696.6.3.el6.x86_64 x86_64
arch_bits:64
multiplexing_api:epoll
gcc_version:4.4.7
process_id:26318
run_id:7954f18bcb4084964efb58460027399d583fba57
tcp_port:6379
uptime_in_seconds:14402
uptime_in_days:0
hz:10
lru_clock:9455690
executable:/usr/local/bin/redis-server
config_file:/etc/redis/6379.conf

# Clients
connected_clients:7
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0

# Memory
used_memory:2017176
used_memory_human:1.92M
used_memory_rss:9969664
used_memory_rss_human:9.51M
used_memory_peak:2098064
used_memory_peak_human:2.00M
total_system_memory:2103533568
total_system_memory_human:1.96G
used_memory_lua:37888
used_memory_lua_human:37.00K
maxmemory:0
maxmemory_human:0B
maxmemory_policy:noeviction
mem_fragmentation_ratio:4.94
mem_allocator:jemalloc-4.0.3

# Persistence
loading:0
rdb_changes_since_last_save:0
rdb_bgsave_in_progress:0
rdb_last_save_time:1502627793
rdb_last_bgsave_status:ok
rdb_last_bgsave_time_sec:0
rdb_current_bgsave_time_sec:-1
aof_enabled:0
aof_rewrite_in_progress:0
aof_rewrite_scheduled:0
aof_last_rewrite_time_sec:-1
aof_current_rewrite_time_sec:-1
aof_last_bgrewrite_status:ok
aof_last_write_status:ok

# Stats
total_connections_received:20
total_commands_processed:89212
instantaneous_ops_per_sec:6
total_net_input_bytes:6172607
total_net_output_bytes:33781397
instantaneous_input_kbps:0.26
instantaneous_output_kbps:0.67
rejected_connections:0
sync_full:1
sync_partial_ok:0
sync_partial_err:0
expired_keys:0
evicted_keys:0
keyspace_hits:0
keyspace_misses:0
pubsub_channels:1
pubsub_patterns:0
latest_fork_usec:643
migrate_cached_sockets:0

# Replication
role:master #当前 host 的角色
connected_slaves:1
slave0:ip=10.1.4.82,port=6379,state=online,offset=23160,lag=1 #看到从节点的一些信息
master_repl_offset:23160
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:23159

# CPU
used_cpu_sys:10.40
used_cpu_user:6.24
used_cpu_sys_children:0.00
used_cpu_user_children:0.00

# Cluster
cluster_enabled:0

# Keyspace
db0:keys=5,expires=0,avg_ttl=0

设置相关的 key 检查
master
127.0.0.1:6379> dbsize
(integer) 5
127.0.0.1:6379> keys *
1) “winnerlook”
2) “redis”
3) “bund”
4) “baidu”
5) “bund33”
127.0.0.1:6379>

slave
127.0.0.1:6379> dbsize
(integer) 5
127.0.0.1:6379> keys *
1) “winnerlook”
2) “redis”
3) “bund”
4) “baidu”
5) “bund33”
127.0.0.1:6379>

由此可见配置的 redis 主从是可以正常工作的，接下来就是准备配置 Sentinel，并启动相关的服务。
10.1.4.99 sentinel 1 配置文件
pdaemonize yes #后台运行
protected-mode no #保护模式关闭
# Generated by CONFIG REWRITE
dir “/etc/redis”
port 26379 #哨兵端口
sentinel monitor master1 10.1.4.99 6379 2 # 监听 IP 端口默认最少投票数量
sentinel down-after-milliseconds master1 5000
sentinel failover-timeout master1 5000 #选举超时时间
logfile “/data/redis/sentinel/sentinel_26379.log” #日志文件
sentinel auth-pass master1 Redis2017 #redis 密码

10.1.4.99 sentinel 2 配置文件
pdaemonize yes #后台运行
protected-mode no #保护模式关闭
# Generated by CONFIG REWRITE
dir “/etc/redis”
port 26380 #哨兵端口
sentinel monitor master1 10.1.4.99 6379 2 # 监听 IP 端口默认最少投票数量
sentinel down-after-milliseconds master1 5000
sentinel failover-timeout master1 5000 #选举超时时间
logfile “/data/redis/sentinel/sentinel_26379.log” #日志文件
sentinel auth-pass master1 Redis2017 #redis 密码

10.1.4.82 sentinel 1 配置
pdaemonize yes #后台运行
protected-mode no #保护模式关闭
# Generated by CONFIG REWRITE
dir “/etc/redis”
port 26379 #哨兵端口
sentinel monitor master1 10.1.4.99 6379 2 # 监听 IP 端口默认最少投票数量
sentinel down-after-milliseconds master1 5000
sentinel failover-timeout master1 5000 #选举超时时间
logfile “/data/redis/sentinel/sentinel_26379.log” #日志文件
sentinel auth-pass master1 Redis2017 #redis 密码

10.1.4.82 sentinel 2 配置
pdaemonize yes #后台运行
protected-mode no #保护模式关闭
# Generated by CONFIG REWRITE
dir “/etc/redis”
port 26380 #哨兵端口
sentinel monitor master1 10.1.4.99 6379 2 # 监听 IP 端口默认最少投票数量
sentinel down-after-milliseconds master1 5000
sentinel failover-timeout master1 5000 #选举超时时间
logfile “/data/redis/sentinel/sentinel_26379.log” #日志文件
sentinel auth-pass master1 Redis2017 #redis 密码

启动哨兵服务的两种方式
1、redis-sentinel /path/to/sentinel.conf

2、redis-server /path/to/sentinel.conf –sentinel

启动 10.1.4.99 的哨兵服务
redis-sentinel /etc/redis/sentinel_26380.conf

redis-sentinel /etc/redis/sentinel_26379.conf

检查 26379 端口相关日志
[root@bundcredit sentinel]# tail -f sentinel_26379.log
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘

27098:X 13 Aug 21:51:25.242 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
27098:X 13 Aug 21:51:25.242 # Sentinel ID is 361c7d3014a041a1a74163355882d88f5fab7581
27098:X 13 Aug 21:51:25.242 # +monitor master master1 10.1.4.99 6379 quorum 2
27098:X 13 Aug 21:51:30.271 # +sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:51:30.410 # -sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:52:30.617 # +sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:23.855 # -sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.463 # +sdown master master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.532 # +odown master master1 10.1.4.99 6379 #quorum 2/2
27098:X 13 Aug 21:53:34.532 # +new-epoch 1
27098:X 13 Aug 21:53:34.532 # +try-failover master master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.541 # +vote-for-leader 361c7d3014a041a1a74163355882d88f5fab7581 1
27098:X 13 Aug 21:53:34.542 # b73258f1019f65c5fee3b88b9c2eae7f85d985f3 voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:34.559 # 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:34.560 # 76d5a26748410e72ca703e255f44a5ed2b3f83e4 voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:35.156 # +config-update-from sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:35.156 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
27098:X 13 Aug 21:53:35.156 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27098:X 13 Aug 21:53:40.173 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27098:X 13 Aug 21:54:07.583 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379

检查 26380 端口相关日志
[root@bundcredit sentinel]# tail -f sentinel_26379.log
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘

27098:X 13 Aug 21:51:25.242 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
27098:X 13 Aug 21:51:25.242 # Sentinel ID is 361c7d3014a041a1a74163355882d88f5fab7581
27098:X 13 Aug 21:51:25.242 # +monitor master master1 10.1.4.99 6379 quorum 2
27098:X 13 Aug 21:51:30.271 # +sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:51:30.410 # -sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:52:30.617 # +sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:23.855 # -sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.463 # +sdown master master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.532 # +odown master master1 10.1.4.99 6379 #quorum 2/2
27098:X 13 Aug 21:53:34.532 # +new-epoch 1
27098:X 13 Aug 21:53:34.532 # +try-failover master master1 10.1.4.99 6379
27098:X 13 Aug 21:53:34.541 # +vote-for-leader 361c7d3014a041a1a74163355882d88f5fab7581 1
27098:X 13 Aug 21:53:34.542 # b73258f1019f65c5fee3b88b9c2eae7f85d985f3 voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:34.559 # 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:34.560 # 76d5a26748410e72ca703e255f44a5ed2b3f83e4 voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27098:X 13 Aug 21:53:35.156 # +config-update-from sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
27098:X 13 Aug 21:53:35.156 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
27098:X 13 Aug 21:53:35.156 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27098:X 13 Aug 21:53:40.173 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27098:X 13 Aug 21:54:07.583 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
^C
[root@bundcredit sentinel]# tail -f sentinel_26369.log
tail: cannot open `sentinel_26369.log’ for reading: No such file or directory
tail: no files remaining
[root@bundcredit sentinel]# tail -f sentinel_26380.log
27102:X 13 Aug 21:53:34.496 # +sdown master master1 10.1.4.99 6379
27102:X 13 Aug 21:53:34.558 # +new-epoch 1
27102:X 13 Aug 21:53:34.560 # +vote-for-leader b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
27102:X 13 Aug 21:53:34.580 # +odown master master1 10.1.4.99 6379 #quorum 4/2
27102:X 13 Aug 21:53:34.580 # Next failover delay: I will not start a failover before Sun Aug 13 21:53:45 2017
27102:X 13 Aug 21:53:35.156 # +config-update-from sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
27102:X 13 Aug 21:53:35.156 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
27102:X 13 Aug 21:53:35.156 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 21:53:40.201 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 21:54:07.583 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379

启动 10.1.4.82 服务器相关服务
redis-sentinel /etc/redis/sentinel_26380.conf

redis-sentinel /etc/redis/sentinel_26379.conf

检查 26379 端口相关日志
15947:X 13 Aug 21:45:33.882 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
15947:X 13 Aug 21:45:33.893 # Sentinel ID is 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac
15947:X 13 Aug 21:45:33.893 # +monitor master master1 10.1.4.99 6379 quorum 2
15947:X 13 Aug 21:45:33.894 * +slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:45:39.170 * Increased maximum number of open files to 10032 (it was originally set to 1024).
_._
_.-“__ ”-._
_.-“ `. `_. ”-._ Redis 3.2.9 (00000000/0) 64 bit
.-“ .-“`. “`\/ _.,_ ”-._
(‘ , .-` | `,) Running in sentinel mode
|`-._`-…-` __…-.“-._|’` _.-‘| Port: 26380
| `-._ `._ / _.-‘ | PID: 15951
`-._ `-._ `-./ _.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ | http://redis.io
`-._ `-._`-.__.-‘_.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ |
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘

15951:X 13 Aug 21:45:39.171 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
15951:X 13 Aug 21:45:39.174 # Sentinel ID is b73258f1019f65c5fee3b88b9c2eae7f85d985f3
15951:X 13 Aug 21:45:39.174 # +monitor master master1 10.1.4.99 6379 quorum 2
15951:X 13 Aug 21:45:39.175 * +slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:45:40.025 * +sentinel sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:45:41.196 * +sentinel sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:45:57.729 * +sentinel sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:45:57.729 * +sentinel sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:46:05.114 * +sentinel sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:46:05.115 * +sentinel sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:47:16.648 # +sdown master master1 10.1.4.99 6379
15951:X 13 Aug 21:47:20.907 # +sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:47:20.908 # +sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:47:20.908 # +sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:47:20.979 # +tilt #tilt mode entered
15947:X 13 Aug 21:47:20.979 # +tilt #tilt mode entered
15947:X 13 Aug 21:47:50.982 # -tilt #tilt mode exited
15947:X 13 Aug 21:47:50.983 # -sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:47:51.030 # -tilt #tilt mode exited
15951:X 13 Aug 21:47:51.030 # -sdown master master1 10.1.4.99 6379
15951:X 13 Aug 21:47:51.030 # -sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15951:X 13 Aug 21:47:51.030 # -sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:48:42.378 # +sdown sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:49:06.458 # -sdown sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:49:42.140 # +sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:50:59.960 # +sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:51:20.923 # -sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:51:26.062 # -sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
15947:X 13 Aug 21:52:20.592 # User requested shutdown…
15947:X 13 Aug 21:52:20.592 * Removing the pid file.
15947:X 13 Aug 21:52:20.592 # Sentinel is now ready to exit, bye bye…
17056:X 13 Aug 21:53:18.720 * Increased maximum number of open files to 10032 (it was originally set to 1024).
_._
_.-“__ ”-._
_.-“ `. `_. ”-._ Redis 3.2.9 (00000000/0) 64 bit
.-“ .-“`. “`\/ _.,_ ”-._
(‘ , .-` | `,) Running in sentinel mode
|`-._`-…-` __…-.“-._|’` _.-‘| Port: 26379
| `-._ `._ / _.-‘ | PID: 17056
`-._ `-._ `-./ _.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ | http://redis.io
`-._ `-._`-.__.-‘_.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ |
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘

17056:X 13 Aug 21:53:18.721 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
17056:X 13 Aug 21:53:18.721 # Sentinel ID is 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac
17056:X 13 Aug 21:53:18.721 # +monitor master master1 10.1.4.99 6379 quorum 2
17056:X 13 Aug 21:53:29.549 # +sdown master master1 10.1.4.99 6379
17056:X 13 Aug 21:53:29.643 # +new-epoch 1
17056:X 13 Aug 21:53:29.645 # +vote-for-leader b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
17056:X 13 Aug 21:53:29.645 # +odown master master1 10.1.4.99 6379 #quorum 2/2
17056:X 13 Aug 21:53:29.645 # Next failover delay: I will not start a failover before Sun Aug 13 21:53:39 2017
17056:X 13 Aug 21:53:30.241 # +config-update-from sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
17056:X 13 Aug 21:53:30.241 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
17056:X 13 Aug 21:53:30.241 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
17056:X 13 Aug 21:53:35.285 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
17056:X 13 Aug 21:54:02.488 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
17056:X 13 Aug 21:54:12.441 * +convert-to-slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379

检查 26380 端口相关日志
[root@localhost redis]# tail -200f /data/redis/sentinel/sentinel_26380.log
16390:X 13 Aug 21:49:05.965 * Increased maximum number of open files to 10032 (it was originally set to 1024).
_._
_.-“__ ”-._
_.-“ `. `_. ”-._ Redis 3.2.9 (00000000/0) 64 bit
.-“ .-“`. “`\/ _.,_ ”-._
(‘ , .-` | `,) Running in sentinel mode
|`-._`-…-` __…-.“-._|’` _.-‘| Port: 26380
| `-._ `._ / _.-‘ | PID: 16390
`-._ `-._ `-./ _.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ | http://redis.io
`-._ `-._`-.__.-‘_.-‘ _.-‘
|`-._`-._ `-.__.-‘ _.-‘_.-‘|
| `-._`-._ _.-‘_.-‘ |
`-._ `-._`-.__.-‘_.-‘ _.-‘
`-._ `-.__.-‘ _.-‘
`-._ _.-‘
`-.__.-‘

16390:X 13 Aug 21:49:05.966 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
16390:X 13 Aug 21:49:05.966 # Sentinel ID is b73258f1019f65c5fee3b88b9c2eae7f85d985f3
16390:X 13 Aug 21:49:05.966 # +monitor master master1 10.1.4.99 6379 quorum 2
16390:X 13 Aug 21:49:42.173 # +sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:50:59.918 # +sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:51:21.049 # -sdown sentinel 361c7d3014a041a1a74163355882d88f5fab7581 10.1.4.99 26379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:51:25.188 # -sdown sentinel 76d5a26748410e72ca703e255f44a5ed2b3f83e4 10.1.4.99 26380 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:52:25.659 # +sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:19.651 # -sdown sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.563 # +sdown master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.615 # +odown master master1 10.1.4.99 6379 #quorum 3/2
16390:X 13 Aug 21:53:29.615 # +new-epoch 1
16390:X 13 Aug 21:53:29.615 # +try-failover master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.626 # +vote-for-leader b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
16390:X 13 Aug 21:53:29.627 # 361c7d3014a041a1a74163355882d88f5fab7581 voted for 361c7d3014a041a1a74163355882d88f5fab7581 1
16390:X 13 Aug 21:53:29.645 # 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
16390:X 13 Aug 21:53:29.646 # 76d5a26748410e72ca703e255f44a5ed2b3f83e4 voted for b73258f1019f65c5fee3b88b9c2eae7f85d985f3 1
16390:X 13 Aug 21:53:29.698 # +elected-leader master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.698 # +failover-state-select-slave master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.764 # +selected-slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.764 * +failover-state-send-slaveof-noone slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:29.826 * +failover-state-wait-promotion slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:30.179 # +promoted-slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
16390:X 13 Aug 21:53:30.179 # +failover-state-reconf-slaves master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:30.237 # +failover-end master master1 10.1.4.99 6379
16390:X 13 Aug 21:53:30.237 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
16390:X 13 Aug 21:53:30.238 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
16390:X 13 Aug 21:53:35.295 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
16390:X 13 Aug 21:54:02.671 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379

检查 redis 主从和哨兵的状态
10.1.4.99 主从状态
127.0.0.1:6379> info [section]
# Replication
role:master
connected_slaves:1
slave0:ip=10.1.4.82,port=6379,state=online,offset=2678,lag=0
master_repl_offset:2678
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:2677

哨兵状态
[root@bundcredit redis]# redis-cli -p 26379 -a “Redis2017”
127.0.0.1:26379> info
# Sentinel
sentinel_masters:1
sentinel_tilt:0
sentinel_running_scripts:0
sentinel_scripts_queue_length:0
sentinel_simulate_failure_flags:0
master0:name=master1,status=ok,address=10.1.4.99:6379,slaves=1,sentinels=4

10.1.4.82 主从状态
127.0.0.1:6379> info [section]
# Replication
# Replication
role:slave
master_host:10.1.4.99
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:49526
slave_priority:100
slave_read_only:0
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

哨兵状态
[root@bundcredit redis]# redis-cli -p 26379 -a “Redis2017”
127.0.0.1:26379> info
# Sentinel
sentinel_masters:1
sentinel_tilt:0
sentinel_running_scripts:0
sentinel_scripts_queue_length:0
sentinel_simulate_failure_flags:0
master0:name=master1,status=ok,address=10.1.4.99:6379,slaves=1,sentinels=4
127.0.0.1:26379>

异常测试
1、停止 10.1.4.99 的 redis 服务
[root@bundcredit redis]# redis-cli -h 10.1.4.99 -p 6379 -a “Redis2017”
10.1.4.99:6379> SHUTDOWN
not connected>

2、哨兵日志
27102:X 13 Aug 21:53:40.201 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 21:54:07.583 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 22:17:23.410 # +sdown master master1 10.1.4.82 6379
27102:X 13 Aug 22:17:23.445 # +new-epoch 2
27102:X 13 Aug 22:17:23.447 # +vote-for-leader 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 2
27102:X 13 Aug 22:17:23.462 # +odown master master1 10.1.4.82 6379 #quorum 3/2
27102:X 13 Aug 22:17:23.462 # Next failover delay: I will not start a failover before Sun Aug 13 22:17:34 2017
27102:X 13 Aug 22:17:24.499 # -odown master master1 10.1.4.82 6379
27102:X 13 Aug 22:17:24.533 # +config-update-from sentinel 5c3033c0ea6d1e0d861e9d9e99e94edb49c5daac 10.1.4.82 26379 @ master1 10.1.4.82 6379
27102:X 13 Aug 22:17:24.533 # +switch-master master1 10.1.4.82 6379 10.1.4.99 6379
27102:X 13 Aug 22:17:24.534 * +slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
27102:X 13 Aug 22:17:29.580 # +sdown slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
27102:X 13 Aug 22:17:33.951 # -sdown slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
27102:X 13 Aug 22:17:43.855 * +convert-to-slave slave 10.1.4.82:6379 10.1.4.82 6379 @ master1 10.1.4.99 6379
27102:X 13 Aug 22:24:14.405 # +sdown master master1 10.1.4.99 6379
27102:X 13 Aug 22:24:14.445 # +new-epoch 3
27102:X 13 Aug 22:24:14.446 # +vote-for-leader b73258f1019f65c5fee3b88b9c2eae7f85d985f3 3
27102:X 13 Aug 22:24:14.477 # +odown master master1 10.1.4.99 6379 #quorum 4/2
27102:X 13 Aug 22:24:14.477 # Next failover delay: I will not start a failover before Sun Aug 13 22:24:24 2017
27102:X 13 Aug 22:24:15.600 # +config-update-from sentinel b73258f1019f65c5fee3b88b9c2eae7f85d985f3 10.1.4.82 26380 @ master1 10.1.4.99 6379
27102:X 13 Aug 22:24:15.601 # +switch-master master1 10.1.4.99 6379 10.1.4.82 6379
27102:X 13 Aug 22:24:15.601 * +slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 22:24:20.627 # +sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 22:25:49.007 # -sdown slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379
27102:X 13 Aug 22:25:58.984 * +convert-to-slave slave 10.1.4.99:6379 10.1.4.99 6379 @ master1 10.1.4.82 6379

3、检查服务
10.1.4.82
# Replication
role:master
connected_slaves:1
slave0:ip=10.1.4.99,port=6379,state=online,offset=17942,lag=0
master_repl_offset:17942
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:17941

启动 10.1.4.99
检查服务
# Replication
role:slave
master_host:10.1.4.82
master_port:6379
master_link_status:up
master_last_io_seconds_ago:0
master_sync_in_progress:0
slave_repl_offset:2546
slave_priority:100
slave_read_only:0
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

再次停止 10.1.4.82 redis 服务服务正常

注意事项：
在配置 redis.conf 时需要注意以下事项
1、protected-mode no #保护模式关闭在 3.2 版本后添加的安全模式最好关闭
2、slave-read-only no #默认的从库不支持写入，这里需要开启，当经过哨兵写入时才支持写入数据

在配置 sentinel.conf 时需要注意
1、pdaemonize yes #后台运行
2、protected-mode no #保护模式关闭

3、sentinel monitor master1 10.1.4.99 6379 2 # 监听 IP 端口默认最少投票数量
4、sentinel down-after-milliseconds master1 5000
5、sentinel failover-timeout master1 5000 #选举超时时间
6、logfile “/data/redis/sentinel/sentinel_26379.log” #日志文件
7、sentinel auth-pass master1 Redis2017 #redis 密码如果主从设置密码后记得要设置密码，否则不能登录

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本文永久更新链接地址：http://www.linuxidc.com/Linux/2017-08/146251.htm