目前redis支持的cluster特性
1):节点自动发现
2):slave->master 选举,集群容错
3):Hot resharding:在线分片
4):进群管理:cluster xxx
5):基于配置(nodes-port.conf)的集群管理
6):ASK 转向/MOVED 转向机制.
1)redis-cluster架构图
架构细节:
(1)所有的redis节点彼此互联(PING-PONG机制),内部使用二进制协议优化传输速度和带宽.
(2)节点的fail是通过集群中超过半数的节点检测失效时才生效.
(3)客户端与redis节点直连,不需要中间proxy层.客户端不需要连接集群所有节点,连接集群中任何一个可用节点即可
(4)redis-cluster把所有的物理节点映射到[0-16383]slot上,cluster 负责维护node<->slot<->value
2) redis-cluster选举:容错
(1)领着选举过程是集群中所有master参与,如果半数以上master节点与master节点通信超过(cluster-node-timeout),认为当前master节点挂掉.
(2):什么时候整个集群不可用(cluster_state:fail),当集群不可用时,所有对集群的操作做都不可用，收到((error) CLUSTERDOWN The cluster is down)错误
a:如果集群任意master挂掉,且当前master没有slave.集群进入fail状态,也可以理解成进群的slot映射[0-16383]不完成时进入fail状态.
b:如果进群超过半数以上master挂掉，无论是否有slave集群进入fail状态.
一、环境
os：centos7redis：3.2.9gem-redis：3.2.2（可去下载最新版噢）二、搭建集群
1、本机下载redis-3.2.9.tar.gz
redis官网：https://redis.io/download2、解压安装redis（最少准备 6 个~3m3s）
这个可以参考这个 文章地址
3、安装ruby依赖
yum install ruby rubygems -y 4、本机下载安装gem-redis
下载：https://rubygems.org/gems/redis/versions/3.2.2安装：gem install -l /opt/redis-3.2.2.gem 5、配置redis－config 1)redis配置文件结构: 使用包含(include)把通用配置和特殊配置分离,方便维护 .2)redis通用配置. #GENERAL daemonize no tcp-backlog 511 timeout 0 tcp-keepalive 0 loglevel notice databases 16 slave-serve-stale-data yes #slave只读 slave-read-only yes #not use default repl-disable-tcp-nodelay yes slave-priority 100 #打开aof持久化 appendonly no #每秒一次aof写 appendfsync everysec #关闭在aof rewrite的时候对新的写操作进行fsync no-appendfsync-on-rewrite yes auto-aof-rewrite-min-size 64mb lua-time-limit 5000 #打开redis集群 cluster-enabled yes #节点互连超时的阀值 cluster-node-timeout 15000 cluster-migration-barrier 1 slowlog-log-slower-than 10000 slowlog-max-len 128 notify-keyspace-events "" hash-max-ziplist-entries 512 hash-max-ziplist-value 64 list-max-ziplist-entries 512 list-max-ziplist-value 64 set-max-intset-entries 512 zset-max-ziplist-entries 128 zset-max-ziplist-value 64 activerehashing yes client-output-buffer-limit normal 0 0 0 client-output-buffer-limit slave 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 hz 10 aof-rewrite-incremental-fsync yes protected-mode no 3)redis特殊配置.（例如6379的配置） /sys/fs/cgroup/ 为docker 挂载地址 #包含通用配置 include /sys/fs/cgroup/newconfig/redis_cluster_common.conf #监听tcp端口 port 6379 #rdb文件,只用于动态添加slave过程 dbfilename "dump6379.rdb" pidfile "/sys/fs/cgroup/redis_6379.pid" logfile "/sys/fs/cgroup/redis_6379.log" dbfilename "dump6379.rdb" dir "/sys/fs/cgroup" #aof存储文件 appendfilename "appendonly-6379.aof" #最大可用内存 maxmemory 100m #内存耗尽时采用的淘汰策略: # volatile-lru -> remove the key with an expire set using an LRU algorithm # allkeys-lru -> remove any key accordingly to the LRU algorithm # volatile-random -> remove a random key with an expire set # allkeys-random -> remove a random key, any key # volatile-ttl -> remove the key with the nearest expire time (minor TTL) # noeviction -> don't expire at all, just return an error on write operations maxmemory-policy allkeys-lru #cluster配置文件(启动自动生成) cluster-config-file nodes-6379.conf #部署在同一机器的redis实例，把auto-aof-rewrite搓开， #防止瞬间fork所有redis进程做rewrite,占用大量内存 80-100 auto-aof-rewrite-percentage 80 6、启动6个redis实例 怎么启动就不说了 7、创建集群 ./redis-trib.rb create --replicas 1 127.0.0.1:6379 127.0.0.1:6380 127.0.0.1:6381 127.0.0.1:6382 127.0.0.1:6383 127.0.0.1:6384记得输入：yes [root@localhost redis-cluster]# ./redis-trib.rb create --replicas 1 127.0.0.1:6379 127.0.0.1:6380 127.0.0.1:6381 127.0.0.1:6382 127.0.0.1:6383 127.0.0.1:6384 >>> Creating cluster >>> Performing hash slots allocation on 6 nodes... Using 3 masters: 127.0.0.1:6379 127.0.0.1:6380 127.0.0.1:6381 Adding replica 127.0.0.1:6382 to 127.0.0.1:6379 Adding replica 127.0.0.1:6383 to 127.0.0.1:6380 Adding replica 127.0.0.1:6384 to 127.0.0.1:6381 M: dfd510594da614469a93a0a70767ec9145aefb1a 127.0.0.1:6379 slots:0-5460 (5461 slots) master M: e02eac35110bbf44c61ff90175e04d55cca097ff 127.0.0.1:6380 slots:5461-10922 (5462 slots) master M: 4385809e6f4952ecb122dbfedbee29109d6bb234 127.0.0.1:6381 slots:10923-16383 (5461 slots) master S: ec02c9ef3acee069e8849f143a492db18d4bb06c 127.0.0.1:6382 replicates dfd510594da614469a93a0a70767ec9145aefb1a S: 83e5a8bb94fb5aaa892cd2f6216604e03e4a6c75 127.0.0.1:6383 replicates e02eac35110bbf44c61ff90175e04d55cca097ff S: 10c097c429ca24f8720986c6b66f0688bfb901ee 127.0.0.1:6384 replicates 4385809e6f4952ecb122dbfedbee29109d6bb234 Can I set the above configuration? (type 'yes' to accept): yes >>> Nodes configuration updated >>> Assign a different config epoch to each node >>> Sending CLUSTER MEET messages to join the cluster Waiting for the cluster to join...... >>> Performing Cluster Check (using node 127.0.0.1:6379) M: dfd510594da614469a93a0a70767ec9145aefb1a 127.0.0.1:6379 slots:0-5460 (5461 slots) master M: e02eac35110bbf44c61ff90175e04d55cca097ff 127.0.0.1:6380 slots:5461-10922 (5462 slots) master M: 4385809e6f4952ecb122dbfedbee29109d6bb234 127.0.0.1:6381 slots:10923-16383 (5461 slots) master M: ec02c9ef3acee069e8849f143a492db18d4bb06c 127.0.0.1:6382 slots: (0 slots) master replicates dfd510594da614469a93a0a70767ec9145aefb1a M: 83e5a8bb94fb5aaa892cd2f6216604e03e4a6c75 127.0.0.1:6383 slots: (0 slots) master replicates e02eac35110bbf44c61ff90175e04d55cca097ff M: 10c097c429ca24f8720986c6b66f0688bfb901ee 127.0.0.1:6384 slots: (0 slots) master replicates 4385809e6f4952ecb122dbfedbee29109d6bb234 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. 8、java简单测试代码 import java.io.IOException; import java.util.HashSet; import java.util.Set; import redis.clients.jedis.HostAndPort; import redis.clients.jedis.JedisCluster; import redis.clients.jedis.JedisPoolConfig; public class RedisClusterTest { public static void main(String[] args) throws IOException { JedisCluster jedisCluster=null; try{ JedisPoolConfig config = new JedisPoolConfig(); config.setMaxTotal(1000); config.setMaxIdle(100); config.setTestOnBorrow(true); Set<HostAndPort> nodes = new HashSet<HostAndPort>(); String host="192.168.1.107"; HostAndPort hostAndPort = new HostAndPort(host,6379); HostAndPort hostAndPort1 = new HostAndPort(host,6380); HostAndPort hostAndPort2 = new HostAndPort(host,6381); HostAndPort hostAndPort3 = new HostAndPort(host,6382); HostAndPort hostAndPort4 = new HostAndPort(host,6383); HostAndPort hostAndPort5 = new HostAndPort(host,6384); nodes.add(hostAndPort); nodes.add(hostAndPort1); nodes.add(hostAndPort2); nodes.add(hostAndPort3); nodes.add(hostAndPort4); nodes.add(hostAndPort5); jedisCluster=new JedisCluster(nodes,5000,config); jedisCluster.set("kkk", "1"); String kkk = jedisCluster.get("kkk"); System.out.println(kkk); }finally { if(null!=jedisCluster) jedisCluster.close(); } } }
