Redis cluster集群搭建

2023-08-18 09:15:40

一、redis集群基本介绍

Redis 集群是一个可以在多个 Redis 节点之间进行数据共享的设施installation。

Redis 集群不支持那些需要同时处理多个键的 Redis 命令， 因为执行这些命令需要在多个 Redis 节点之间移动数据， 并且在高负载的情况下， 这些命令将降低Redis集群的性能， 并导致不可预测的行为。

Redis 集群通过分区partition来提供一定程度的可用性availability： 即使集群中有一部分节点失效或者无法进行通讯， 集群也可以继续处理命令请求。

将数据自动切分(split)到多个节点的能力。

当集群中的一部分节点失效或者无法进行通讯时，仍然可以继续处理命令请求的能力。

二、redis集群数据共享

Redis集群使用数据分片(sharding)而非一致性哈希(consistency hashing)来实现：一个Redis集群包含16384个哈希槽(hash slot)，数据库中的每个键都属于这16384个哈希槽的其中一个，集群使用公CRC16(key)%16384来计算键key属于哪个槽，其中CRC16(key)语句用于计算键key的CRC16校验和。

节点A负责处理0号至5500号哈希槽。

节点B负责处理5501号至11000号哈希槽。

节点C负责处理11001号至16384号哈希槽。

三、redis cluster

Redis cluster集群搭建

四、集群安装部署

6个redis实例，一般会放到3台硬件服务器
注：在企业规划中，一个分片的两个分到不同的物理机，防止硬件主机宕机造成整个分片数据丢失。

4.1 安装基础软件

# 安装redis，带有redis-trib.rb命令
wget http://download.redis.io/releases/redis-3.2.12.tar.gz
tar xf redis-3.2.12.tar.gz -C /usr/local/
mv /usr/local/redis-3.2.12/ /usr/local/redis
cd /usr/local/redis/
make
PATH=/usr/local/redis/src:$PATH
source /etc/profile

# 安装ruby软件支持
yum install ruby rubygems -y
gem sources -l

# 修改为国内源
gem sources -a http://mirrors.aliyun.com/rubygems/
gem sources --remove https://rubygems.org/
gem sources -l

# 安装redis集群软件，可以指定版本，否则为最新版本
gem install redis -v 3.3.3

 

4.2 创建各节点配置文件

mkdir -p /data/700{0..5}
vim /data/7000/redis.conf
port 7000
daemonize yes
pidfile /data/7000/redis.pid
loglevel notice
logfile /data/7000/redis.log
dbfilename dump.rdb
dir /data/7000
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7001/redis.conf
port 7001
daemonize yes
pidfile /data/7001/redis.pid
loglevel notice
logfile /data/7001/redis.log
dbfilename dump.rdb
dir /data/7001
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7002/redis.conf
port 7002
daemonize yes
pidfile /data/7002/redis.pid
loglevel notice
logfile /data/7002/redis.log
dbfilename dump.rdb
dir /data/7002
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7003/redis.conf
port 7003
daemonize yes
pidfile /data/7003/redis.pid
loglevel notice
logfile /data/7003/redis.log
dbfilename dump.rdb
dir /data/7003
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7004/redis.conf
port 7004
daemonize yes
pidfile /data/7004/redis.pid
loglevel notice
logfile /data/7004/redis.log
dbfilename dump.rdb
dir /data/7004
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7005/redis.conf
port 7005
daemonize yes
pidfile /data/7005/redis.pid
loglevel notice
logfile /data/7005/redis.log
dbfilename dump.rdb
dir /data/7005
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

4.3 启动节点服务

redis-server /data/7000/redis.conf
redis-server /data/7001/redis.conf
redis-server /data/7002/redis.conf
redis-server /data/7003/redis.conf
redis-server /data/7004/redis.conf
redis-server /data/7005/redis.conf

4.4 将节点加入集群

　　会自动将前3个节点认为是master节点，后三个作为对应的从节点。主节点和从节点应该分布到不同的物理节点。

Redis cluster集群搭建
redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
127.0.0.1:7000
127.0.0.1:7001
127.0.0.1:7002
Adding replica 127.0.0.1:7003 to 127.0.0.1:7000
Adding replica 127.0.0.1:7004 to 127.0.0.1:7001
Adding replica 127.0.0.1:7005 to 127.0.0.1:7002
M: c4983be04f95d9c9c848ba692cd42cb9201ff4b5 127.0.0.1:7000
   slots:0-5460 (5461 slots) master
M: 4223ef9cb913d796bb96187f7a737bc232a68d93 127.0.0.1:7001
   slots:5461-10922 (5462 slots) master
M: 4bb6c9008c10530a13379b738eaee8611ac96738 127.0.0.1:7002
   slots:10923-16383 (5461 slots) master
S: 5d112be8cd376d039a4ab2c66141d2fc25c50486 127.0.0.1:7003
   replicates c4983be04f95d9c9c848ba692cd42cb9201ff4b5
S: 9c758f060663f92e60e4c5c2389e33279e72cb7b 127.0.0.1:7004
   replicates 4223ef9cb913d796bb96187f7a737bc232a68d93
S: 78540a81d3d6d9bb6f73f848b7e5fb6b1d3bc5d2 127.0.0.1:7005
   replicates 4bb6c9008c10530a13379b738eaee8611ac96738
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 127.0.0.1:7000)
M: c4983be04f95d9c9c848ba692cd42cb9201ff4b5 127.0.0.1:7000
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
M: 4223ef9cb913d796bb96187f7a737bc232a68d93 127.0.0.1:7001
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
M: 4bb6c9008c10530a13379b738eaee8611ac96738 127.0.0.1:7002
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
S: 5d112be8cd376d039a4ab2c66141d2fc25c50486 127.0.0.1:7003
   slots: (0 slots) slave
   replicates c4983be04f95d9c9c848ba692cd42cb9201ff4b5
S: 9c758f060663f92e60e4c5c2389e33279e72cb7b 127.0.0.1:7004
   slots: (0 slots) slave
   replicates 4223ef9cb913d796bb96187f7a737bc232a68d93
S: 78540a81d3d6d9bb6f73f848b7e5fb6b1d3bc5d2 127.0.0.1:7005
   slots: (0 slots) slave
   replicates 4bb6c9008c10530a13379b738eaee8611ac96738
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005

4.5 集群状态查看

redis-cli -p 7000 cluster nodes| grep master
redis-cli -p 7000 cluster nodes| grep slave

五、集群管理

5.1 新增节点，创建两个节点的目录及配置文件

mkdir /data/700{6,7}
vim /data/7006/redis.conf
port 7006
daemonize yes
pidfile /data/7006/redis.pid
loglevel notice
logfile /data/7006/redis.log
dbfilename dump.rdb
dir /data/7006
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

vim /data/7007/redis.conf
port 7007
daemonize yes
pidfile /data/7007/redis.pid
loglevel notice
logfile /data/7007/redis.log
dbfilename dump.rdb
dir /data/7007
protected-mode no
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
appendonly yes

5.2 启动新增两节点的服务

redis-server /data/7006/redis.conf
redis-server /data/7007/redis.conf

5.3 添加主节点，把7006添加到7000节点所在的主集群中

# redis-trib.rb add-node 127.0.0.1:7006 127.0.0.1:7000
# redis-cli -p 7000 cluster nodes | grep master
c4983be04f95d9c9c848ba692cd42cb9201ff4b5 127.0.0.1:7000 myself,master - 0 0 1 connected 0-5460
10b8ae75c548e46dbabbc5667c0b749813f855e5 127.0.0.1:7006 master - 0 1559015085602 0 connected                     # 添加到集群之后，并没有分配slot槽位，需要我们手动来平均分配
4223ef9cb913d796bb96187f7a737bc232a68d93 127.0.0.1:7001 master - 0 1559015085602 2 connected 5461-10922          # 平均分配计算：16384/4=4096
4bb6c9008c10530a13379b738eaee8611ac96738 127.0.0.1:7002 master - 0 1559015084101 3 connected 10923-16383

5.4 转移slot（重新分片）

redis-trib.rb reshard 127.0.0.1:7000
>>> Performing Cluster Check (using node 127.0.0.1:7000)
M: c4983be04f95d9c9c848ba692cd42cb9201ff4b5 127.0.0.1:7000
   slots:0-5460 (5461 slots) master
   1 additional replica(s)
M: 10b8ae75c548e46dbabbc5667c0b749813f855e5 127.0.0.1:7006
   slots: (0 slots) master
   0 additional replica(s)
M: 4223ef9cb913d796bb96187f7a737bc232a68d93 127.0.0.1:7001
   slots:5461-10922 (5462 slots) master
   1 additional replica(s)
M: 4bb6c9008c10530a13379b738eaee8611ac96738 127.0.0.1:7002
   slots:10923-16383 (5461 slots) master
   1 additional replica(s)
S: 5d112be8cd376d039a4ab2c66141d2fc25c50486 127.0.0.1:7003
   slots: (0 slots) slave
   replicates c4983be04f95d9c9c848ba692cd42cb9201ff4b5
S: 9c758f060663f92e60e4c5c2389e33279e72cb7b 127.0.0.1:7004
   slots: (0 slots) slave
   replicates 4223ef9cb913d796bb96187f7a737bc232a68d93
S: 78540a81d3d6d9bb6f73f848b7e5fb6b1d3bc5d2 127.0.0.1:7005
   slots: (0 slots) slave
   replicates 4bb6c9008c10530a13379b738eaee8611ac96738
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
How many slots do you want to move (from 1 to 16384)? 4096                     # 要移动槽位的大小：4096
What is the receiving node ID? 10b8ae75c548e46dbabbc5667c0b749813f855e5        # 接收节点的ID：7006的ID
Please enter all the source node IDs.
  Type 'all' to use all the nodes as source nodes for the hash slots.          # 键入all以将所有节点用作散列槽的源节点。
  Type 'done' once you entered all the source nodes IDs.                       # 输入所有源节点ID后，键入done。
Source node #1:all                                                             # 输入all所有节点分配槽位
……
Do you want to proceed with the proposed reshard plan (yes/no)? yes            # 是否继续，选择yes

5.5 添加从节点

 

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