Shulou(Shulou.com)06/01 Report--

Today, I will introduce the high availability solution of redis, the sentinel that comes with redis, and simply describe what is sentinel (Sentinel Cluster). Sentinel cluster can encapsulate redis master and slave to achieve redis master downtime. Redis backup will take over the master and automatically upgrade to slave when it is restored again. There are many ways to introduce redis+vip on the Internet, which is very simple to realize the drift of vip after the main downtime. It is true that this method is possible, but there is no way to maximize the utilization of master-slave resources. What I want to show you is how to use sentinel+redis+python (add after downtime alarm) to achieve high availability of redis and separation of redis read and write.

1. Install redis (I use 2 here, production is recommended to use 3)

The specific installation of redis will not be introduced. I am using an ansible installation

I installed two here, 192.168.7.30 to be used as the master redis to write data, 192.168.7.31 is used to read data from.

two。 Configure redis

Because you are using ansible, the configuration file is configured by default and can be started without modification.

172.16.10.30 configuration on the master

[root@redis-master etc] # cat redis_16399.conf bind 172.16.10.30protected-mode yesport 16399tcp-backlog 511timeout 0tcp-keepalive 300daemonize yessupervised nopidfile / usr/local/redis/run/redis_16399.pidloglevel noticelogfile "/ usr/local/redis/logs/redis_16399.log" databases 16save 900 1save 300 10save 60 10000stop-writes-on-bgsave-error yesrdbcompression yesrdbchecksum yesdbfilename dump.rdbdir / data/redis/16399slave-serve-stale-data yesslave-read-only yesrepl-diskless-sync norepl-diskless-sync-delay 5repli- Disable-tcp-nodelay noslave-priority 100appendonly yesappendfilename "appendonly.aof" appendfsync everysecno-appendfsync-on-rewrite noauto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mbaof-load-truncated yeslua-time-limit 5000slowlog-log-slower-than 10000slowlog-max-len 128latency-monitor-threshold 0notify-keyspace-events "hash-max-ziplist-entries 512hash-max-ziplist-value 64list-max-ziplist-size-2list-compress-depth 0set-max-intset-entries 512zset-max-ziplist-entries 128zsetMaxMaxMiziplist- Value 64hll-sparse-max-bytes 3000activerehashing yesclient-output-buffer-limit normal 00 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60hz 10aof-rewrite-incremental-fsync yes [root@redis-master etc] # / etc/init.d/redis_16399 start Starting Redis server... [root@redis-master etc] # netstat-nltp | grep 16399 tcp 00 172.16.10.30 root@redis-master etc 16399 0.0.0.0 root@redis-master etc * LISTEN 5521/redis-server 1 [root@redis-master etc] #

Configuration on 172.16.10.31

[root@master-slave etc] # grep-rn slaveof redis_16399.conf 16:slaveof 172.16.10.30 16399 # there are more slave configuration files than the master. This line [root@master-slave etc] # / etc/init.d/redis_16399 start Starting Redis server... [root@master-slave etc] # netstat-nltpa | grep 16399 tcp 0 0172.16.10.31 root@master-slave etc 16399 0.0.0.0 root@master-slave etc * LISTEN 10466/redis-server tcp 0 0 172.16.10.31:18936 172.16.10.30:16399 ESTABLISHED 10466/redis-server [root@master-slave etc] #

From the above, we can see that the master and slave have been configured.

3. Configure sentinel

All nodes in sentinel configuration files are basically the same, and can be deployed on nodes that are not redis for more comprehensive monitoring.

[root@redis-master etc] # cat sentinel_5001.conf port 5001pidfile "/ usr/local/redis/run/sentinel_5001.pid" loglevel noticelogfile "/ usr/local/redis/logs/sentinel_5001.log" daemonize yesprotected-mode nosentinel monitor mymaster 172.16.10.30 16399 2sentinel down-after-milliseconds mymaster 5000sentinel failover-timeout mymaster 60000 [root@redis-master etc] #

4. Start sentinel

172.16.10.30 start sentinel

[root@master-slave etc] # cat sentnel_5001.conf port 5001pidfile "/ usr/local/redis/run/sentinel_5001.pid" loglevel noticelogfile "/ usr/local/redis/logs/sentinel_5001.log" daemonize yesprotected-mode nosentinel monitor mymaster 172.16.10.30 16399 2sentinel down-after-milliseconds mymaster 5000sentinel failover-timeout mymaster 60000 [root@master-slave etc] # [root@redis-master etc] # / usr/local/redis/bin/redis-sentinel / usr/local/redis/etc/ Sentinel_5001.conf [root@redis-master etc] # tail-30f / usr/local/redis/logs/sentinel_5001.log 5704 tail X 08 Dec 22 tail 46V 44.977 # Not listening to IPv6: unsupproted _. _ _.-```_'-. _.-``` `_. '' -. _ Redis 3.2.11 (000000Universe 0) 64 bit.-``.- ```. ```\ / _., _'-. _ (.-`|` ) Running in sentinel mode | `-. _`...-.`` -. _ |'`_. -'| Port: 5001 |` -. _ `. _ / _. -'| PID: 5704` -. _ `-. _`. / _. -'_. -'| `-. `-. _` -'_. | | `-. _` -. _ _. -'_. -'| http://redis.io `-. _` -. _ _. -'. | | `-. _` -. _ `. -'_. -'| |` -. _ `-. -'_. -'. _. -'`-. _`. -'. 5704 Dec X 08 Dec 22 46 Dec 46 44.986 # Sentinel ID is 453837ef09fc1a41332df32487882f2e422337625704:X 08 44.986 # + monitor master mymaster 172.16.10.30 16399 quorum 25704 14 Dec 22 46 4V 44.987 * + slave slave 172.16.10.31 16399 @ mymaster 172.16.10.30 16399

It has already been monitored here, and the switch will only occur when we configure only 2 nodes above. We now start the sentinel on 172.16.10.31.

[root@master-slave etc] # vim sentnel_5001.conf [root@master-slave etc] # / usr/local/redis/bin/redis-sentinel / usr/local/redis/etc/sentnel_5001.conf [root@master-slave etc] # tail-30f / usr/local/redis/logs/sentinel_5001.log 10615V X 08 Dec 22V 51V 05.232 # Not listening to IPv6: unsupproted _. _.-``_'-. _ _.-```. `_. '' -. _ Redis 3.2.11 (000000Universe 0) 64 bit.-``.- ```. ```\ / _., _'-. _ (.-`|` ) Running in sentinel mode | `-. _`...-.`` -. _ |'`_. -'| Port: 5001 |` -. _ `. _ / _. -'| PID: 10615` -. _ `-. _`. / _. -'_. -'| `-. `-. _` -'_. | | `-. _` -. _ _. -'_. -'| http://redis.io `-. _` -. _ _. -'. | | `-. _` -. _ `. -'_. -'| |` -. _ `-. -'_. -'. _. -'`-. _`. -'. 10615 Dec X 08 Dec 22 Dec 51 Dec 05.234 # monitor master mymaster 172.16.10.30 16399 quorum 210615 quorum 210615 Dec 22 51V 05.235 * + slave slave 172.16.10.31 16399 @ mymaster 172.16.10.30 1639910615 Dec 172.10.30 1639910615 Dec 172.697 * + sentinel sentinel 453837ef09fc1a41332df32487882f2e42233762 172. 16.10.30 5001 @ mymaster 172.16.10.30 16399

So far, we have completed the construction of the sentinel cluster.

5. test

Test master-slave

Test sentinel

Stop the redis of 172.16.10.30

[root@redis-master init.d] # / etc/init.d/redis_16399 stop Stopping... Redis stopped

Sentinel fallover log

10615 Dec X 08 Dec 22 sdown master mymaster 172.16.10.30 1639910615 sdown master mymaster 172.16.30 1639910615 Dec 2215 52V 08.553 # + odown master mymaster 172.16.10.30 16399 # quorum 2According to 210615 Dec 08 Dec 2252mer 08.553 # + new-epoch 110615X 08 Dec 22race 52mer 08.553 # + try-failover master mymaster 172.16.30 1639910615 Dec 2215 Dec 2215 quorum 08 08.554 # + vote-for-leader 0ac7df95b3e057a0ccb4a10f1cc8cc91e071526e 110615 discipline X 08 Dec 2252: 08.556 # 453837ef09fc1a41332df32487882f2e42233762 voted for 0ac7df95b3e057a0ccb4a10f1cc8cc91e071526e 110615 elected-leader master mymaster 172.16.10.30 1639910615 elected-leader master mymaster 172.16.10.30 1639910615 elected-leader master mymaster 172.16.10.30 1639910615 failover-state-select-slave master mymaster 172.16.10.30 1639910615 failover-state-select-slave master mymaster 172.16.10.30 1639910615 failover-state-select-slave master mymaster 172.16.10.30 16399 16399 @ mymaster 172.16.10.31 16399 @ mymaster 172.16.10.30 1639910615 State-send-slaveof-noone slave 172.16.10.31 state-send-slaveof-noone slave 16399 172.16.10.31 16399 @ mymaster 172.16.10.30 1639910615 Dec 2252Val 08.782 * + failover-state-wait-promotion slave 172.16.10.31 16399 @ mymaster 172.16.10.30 1639910615 mymaster 172.16.10.30 1639910615 mymaster 172.715 # + promoted-slave slave 172.16.10.31 1R 16399 172.16.31 16399 @ mymaster .10.30 1639910615 failover-state-reconf-slaves master mymaster 172.16.10.30 1639910615 failover-end master mymaster 172.16.30 1639910615 failover-end master mymaster 172.16.30 16399 16399 172.16.30 163991099 172.16.31 1639910615race X 08 Dec 2252race 09.785 * + slave slave 172.16.10.30 16399 172.16.10. 30 16399 @ mymaster 172.16.10.31 1639910615 Dec X 08 22 sdown slave 22 sdown slave 172.16.10.30 sdown slave 16399 172.16.10.30 16399 @ mymaster 172.16.10.31 16399

172.16.10.30 recovery log

10615 Dec X 08 Dec 22 56 mymaster 172.16.10.30 16399 172.16.10.30 16399 @ mymaster 172.16.10.31 1639910615 convert-to-slave slave 172.16.10.30 16399 172.16.10.30 16399 @ mymaster 172.16.10.31

6.python client implements the separation of read and write.

[root@cmdb redis-sentinel] # tree. ├── eg.py └── redis_cluster ├── _ _ init__.py ├── _ _ init__.pyc ├── RedisSentinel.py ├── RedisSentinel.pyc ├── settings.py └── settings.pyc1 directory, 7 files [root@cmdb redis-sentinel] #

Settings.py is a configuration file

[root@cmdb redis-sentinel] # cat redis_cluster/settings.py#default timeoutSOCKET_TIMEOUT = 0.1#sentinel cluster nodes listSENTINEL_NODES = [('192.168.7.30 sentinel cluster nameCLUSTER_NAME = "mymaster" # default select db CLUSTER_DB= 15 [root@cmdb redis-sentinel] #

RedisSentinel.py is the processing method.

[root@cmdb redis-sentinel] # cat redisfeatured clusterplac RedisSentinel.pyrogen init__ Env python # encoding:utf-8#from redis.sentinel import Sentinelfrom settings import SENTINEL_NODES,SOCKET_TIMEOUT,CLUSTER_NAME,CLUSTER_DBclass RedisSentinelClient: def _ _ cluster (self,sentinel_nodes,socket_timeout,cluster_name,db): self.sentinel=Sentinel (sentinel_nodes) Socket_timeout=socket_timeout) self.master_name=cluster_name self.socket_timeout=socket_timeout self.db=db def master (self,socket_timeout=None): return self.sentinel.master_for (self.master_name,db=self.db,socket_timeout=self.socket_timeout) def slave (self,socket_timeout=None): return self.sentinel.slave_for (self.master_name,db=self.db,socket_timeout=self.socket_timeout) sentinel_client=RedisSentinelClient (SENTINEL_NODES,SOCKET_TIMEOUT CLUSTER_NAME,CLUSTER_DB) master_redis=sentinel_client.master () slave_redis=sentinel_client.slave () [root@cmdb redis-sentinel] #

Eg.py is the method used:

[root@cmdb redis-sentinel] # cat eg.py #! / usr/bin/env python # encoding:utf-8from redis_cluster.RedisSentinel import master_redis,slave_redismaster_redis.set ('ceshi','nihaoma') # write data print slave_redis.get (' ceshi') # read data. The data read here is read from the library [root@cmdb redis-sentinel] #

At this point, the read-write separation operation of python to sentinel sentinel cluster is realized.

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