其他数据库 2023-02-21

k8s部署redis cluster集群的实现

Redis 介绍

Redis代表REmote DIctionary Server是一种开源的内存中数据存储，通常用作数据库，缓存或消息代理。它可以存储和操作高级数据类型，例如列表，地图，集合和排序集合。
由于Redis接受多种格式的密钥，因此可以在服务器上执行操作，从而减少了客户端的工作量。
它仅将磁盘用于持久性，而将数据完全保存在内存中。
Redis是一种流行的数据存储解决方案，并被GitHub，Pinterest，Snapchat，Twitter，StackOverflow，Flickr等技术巨头所使用。

为什么要用Redis

它的速度非常快。它是用ANSI C编写的，并且可以在POSIX系统上运行，例如Linux，Mac OS X和Solaris。
Redis通常被排名为最流行的键/值数据库和最流行的与容器一起使用的NoSQL数据库。
其缓存解决方案减少了对云数据库后端的调用次数。
应用程序可以通过其客户端API库对其进行访问。
所有流行的编程语言都支持Redis。
它是开源且稳定的。

什么是Redis Cluster集群

Redis Cluster是一组Redis实例，旨在通过对数据库进行分区来扩展数据库，从而使其更具弹性。
群集中的每个成员（无论是主副本还是辅助副本）都管理哈希槽的子集。如果主机无法访问，则其从机将升级为主机。在由三个主节点组成的最小Redis群集中，每个主节点都有一个从节点（以实现最小的故障转移），每个主节点都分配有一个介于0到16,383之间的哈希槽范围。节点A包含从0到5000的哈希槽，节点B从5001到10000，节点C从10001到16383。
群集内部的通信是通过内部总线进行的，使用协议传播有关群集的信息或发现新节点。

k8s以StatefulSet方式部署redis cluster集群：

1. 部署nfs

2. 创建pv

3. 部署redis

4. 初始化redis集群

主机说明：

系统	ip	角色	cpu	内存	hostname
CentOS 7.8	192.168.30.128	master	>=2	>=2G	master1
CentOS 7.8	192.168.30.129	master	>=2	>=2G	master2
CentOS 7.8	192.168.30.130	node	>=2	>=2G	node1
CentOS 7.8	192.168.30.131	node	>=2	>=2G	node2
CentOS 7.8	192.168.30.132	node	>=2	>=2G	node3

kubectl get node

NAME      STATUS   ROLES    AGE   VERSION
master1   Ready    master   33d   v1.14.0
master2   Ready    master   33d   v1.14.0
node1     Ready    <none>   33d   v1.14.0
node2     Ready    <none>   33d   v1.14.0
node3     Ready    <none>   33d   v1.14.0

部署nfs

在master2节点上做nfs共享，

yum -y install nfs-utils rpcbind
mkdir -p /data/redis/{cluster0,cluster1,cluster2,cluster3,cluster4,cluster5}
vim /etc/exports

/data/redis/cluster0 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster1 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster2 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster3 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster4 192.168.30.0/24(rw,sync,no_root_squash)
/data/redis/cluster5 192.168.30.0/24(rw,sync,no_root_squash)

chmod -R 755 /data/redis
exportfs -arv
systemctl enable rpcbind && systemctl start rpcbind
systemctl enable nfs && systemctl start nfs

nfs部署完毕。对于需要使用nfs的node节点，都要安装nfs：

yum -y install nfs-utils

创建pv

创建pv：

mkdir -p /home/k8s/redis  && cd /home/k8s/redis
vim pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv0
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster0

—
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv1
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster1

—
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv2
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster2

—
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv3
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster3

—
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv4
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster4

—
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv5
spec:
capacity:
storage: 1Gi
accessModes:
– ReadWriteMany
nfs:
server: 192.168.30.129
path: /data/redis/cluster5

kubectl apply -f pv.yaml

kubectl get pv

NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv0 1Gi RWX Retain Available 3s
nfs-pv1 1Gi RWX Retain Available 3s
nfs-pv2 1Gi RWX Retain Available 3s
nfs-pv3 1Gi RWX Retain Available 3s
nfs-pv4 1Gi RWX Retain Available 3s
nfs-pv5 1Gi RWX Retain Available 3s

pv创建完毕。

部署redis

vim namespace.yaml

apiVersion: v1
kind: Namespace
metadata:
name: public-service

vim redis.conf

appendonly yes
cluster-enabled yes
cluster-config-file /var/lib/redis/nodes.conf
cluster-node-timeout 5000
dir /var/lib/redis
port 6379

vim redis.yaml

apiVersion: v1
kind: Service
metadata:
name: redis
namespace: public-service
labels:
app: redis
spec:
selector:
app: redis
appCluster: redis-cluster
ports:
– name: redis
port: 6379
clusterIP: None

—
apiVersion: v1
kind: Service
metadata:
name: redis-access
namespace: public-service
labels:
app: redis
spec:
selector:
app: redis
appCluster: redis-cluster
ports:
– name: redis-access
protocol: TCP
port: 6379
targetPort: 6379

—
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: redis
namespace: public-service
spec:
serviceName: redis
replicas: 6
selector:
matchLabels:
app: redis
appCluster: redis-cluster
template:
metadata:
labels:
app: redis
appCluster: redis-cluster
spec:
terminationGracePeriodSeconds: 20
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
– weight: 100
podAffinityTerm:
labelSelector:
matchExpressions:
– key: app
operator: In
values:
– redis
topologyKey: kubernetes.io/hostname
containers:
– name: redis
image: redis:latest
command:
– “redis-server”
args:
– “/etc/redis/redis.conf”
– “–protected-mode”
– “no”
resources:
requests:
cpu: “500m”
memory: “500Mi”
ports:
– containerPort: 6379
name: redis
protocol: TCP
– containerPort: 16379
name: cluster
protocol: TCP
volumeMounts:
– name: conf
mountPath: /etc/redis
– name: data
mountPath: /var/lib/redis
volumes:
– name: conf
configMap:
name: redis-conf
items:
– key: redis.conf
path: redis.conf
volumeClaimTemplates:
– metadata:
name: data
namespace: public-service
spec:
accessModes: [ “ReadWriteMany” ]
resources:
requests:
storage: 1Gi

kubectl apply -f namespace.yaml

kubectl create configmap redis-conf –from-file=redis.conf -n public-service

kubectl apply -f redis.yaml

kubectl get svc -n public-service

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
redis ClusterIP None <none> 6379/TCP 20s
redis-access ClusterIP 10.96.2.100 <none> 6379/TCP 20s

kubectl get pod -n public-service

NAME READY STATUS RESTARTS AGE
redis-0 1/1 Running 0 2m43s
redis-1 1/1 Running 0 2m18s
redis-2 1/1 Running 0 108s
redis-3 1/1 Running 0 80s
redis-4 1/1 Running 0 48s
redis-5 1/1 Running 0 30s

kubectl get pvc -n public-service

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
data-redis-0 Bound nfs-pv4 1Gi RWX 3m4s
data-redis-1 Bound nfs-pv0 1Gi RWX 2m39s
data-redis-2 Bound nfs-pv1 1Gi RWX 2m9s
data-redis-3 Bound nfs-pv2 1Gi RWX 101s
data-redis-4 Bound nfs-pv3 1Gi RWX 69s
data-redis-5 Bound nfs-pv5 1Gi RWX 51s

redis-access这个service方便集群内访问redis集群，redis部署完毕。

初始化redis集群

使用Redis-tribe工具进行集群的初始化。

下载redis-tribe：

kubectl run -it ubuntu –image=ubuntu –restart=Never -n public-service bash

root@ubuntu:/# cat > /etc/apt/sources.list << EOF
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse
EOF

root@ubuntu:/# apt-get update

root@ubuntu:/# apt-get install -y libncursesw5 libreadline6 libtinfo5 --allow-remove-essential

root@ubuntu:/# apt-get install -y libpython2.7-stdlib python2.7 python-pip redis-tools dnsutils

root@ubuntu:/# pip install --upgrade pip

root@ubuntu:/# pip install redis-trib==0.5.1

初始化集群：

root@ubuntu:/# redis-trib.py create \
  `dig +short redis-0.redis.public-service.svc.cluster.local`:6379 \
  `dig +short redis-1.redis.public-service.svc.cluster.local`:6379 \
  `dig +short redis-2.redis.public-service.svc.cluster.local`:6379
  
root@ubuntu:/# redis-trib.py replicate \
  --master-addr `dig +short redis-0.redis.public-service.svc.cluster.local`:6379 \
  --slave-addr `dig +short redis-3.redis.public-service.svc.cluster.local`:6379

root@ubuntu:/# redis-trib.py replicate \
  --master-addr `dig +short redis-1.redis.public-service.svc.cluster.local`:6379 \
  --slave-addr `dig +short redis-4.redis.public-service.svc.cluster.local`:6379

root@ubuntu:/# redis-trib.py replicate \
  --master-addr `dig +short redis-2.redis.public-service.svc.cluster.local`:6379 \
  --slave-addr `dig +short redis-5.redis.public-service.svc.cluster.local`:6379
  
root@ubuntu:/# exit

查看集群：

kubectl exec -it -n public-service redis-0 bash

root@redis-0:/data# redis-cli -c

127.0.0.1:6379> CLUSTER NODES #列出节点信息

aac2b3d320da67eedf3512ed0e38a1cdce5bc8fe 172.10.2.55:6379@16379 slave 7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 0 1592276224727 3 connected
2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 172.10.2.54:6379@16379 master – 0 1592276224224 1 connected 0-5461
524f03526a4b683d7d4de19296431810bfdc22cf 172.10.3.60:6379@16379 slave df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 0 1592276223117 5 connected
7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 172.10.4.77:6379@16379 myself,master – 0 1592276224000 2 connected 5462-10922
df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 172.10.3.59:6379@16379 master – 0 1592276223217 0 connected 10923-16383
c1dbaaef4a583e372c43eed52c22cd9ad7184d18 172.10.4.78:6379@16379 slave 2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 0 1592276223719 4 connected

127.0.0.1:6379> CLUSTER INFO #集群状态

cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:5
cluster_my_epoch:2
cluster_stats_messages_ping_sent:514
cluster_stats_messages_pong_sent:491
cluster_stats_messages_meet_sent:2
cluster_stats_messages_sent:1007
cluster_stats_messages_ping_received:491
cluster_stats_messages_pong_received:516
cluster_stats_messages_received:1007

redis集群初始化完成，已经形成3主3从的cluster集群。

写入数据：

127.0.0.1:6379> SET key1 aaa
OK

127.0.0.1:6379> SET key2 bbb
-> Redirected to slot [4998] located at 172.10.2.54:6379
OK

172.10.2.54:6379> SET key3 ccc
OK

kubectl exec -it -n public-service redis-4 bash

root@redis-4:/data# redis-cli -c

127.0.0.1:6379> GET key1
-> Redirected to slot [9189] located at 172.10.4.77:6379
"aaa"

172.10.4.77:6379> GET key2
-> Redirected to slot [4998] located at 172.10.2.54:6379
"bbb"

172.10.2.54:6379> GET key3
"ccc"

可以看出redis cluster集群是去中心化的，每个节点都是平等的，连接哪个节点都可以获取和设置数据。

主从切换：

选择redis-2模拟宕掉，测试主从切换，

kubectl get pod -n public-service -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
redis-0 1/1 Running 0 62m 172.10.4.77 node1 <none> <none>
redis-1 1/1 Running 0 62m 172.10.2.54 node2 <none> <none>
redis-2 1/1 Running 0 61m 172.10.3.59 node3 <none> <none>
redis-3 1/1 Running 0 61m 172.10.2.55 node2 <none> <none>
redis-4 1/1 Running 0 61m 172.10.4.78 node1 <none> <none>
redis-5 1/1 Running 0 61m 172.10.3.60 node3 <none> <none>
ubuntu 0/1 Completed 0 57m 172.10.2.56 node2 <none> <none>

kubectl exec -it -n public-service redis-2 bash

root@redis-2:/data# redis-cli -c

127.0.0.1:6379> ROLE

1) “master”
2) (integer) 2898
3) 1) 1) “172.10.3.60”
2) “6379”
3) “2898”

可以看到，redis-2是master，它的slave是172.10.3.60，即redis-5。

kubectl delete pod -n public-service redis-2 #模拟节点宕掉

kubectl get pod -n public-service redis-2 -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
redis-2 1/1 Running 0 38s 172.10.3.61 node3 <none> <none>

kubectl exec -it -n public-service redis-2 bash

root@redis-2:/data# redis-cli -c

127.0.0.1:6379> ROLE

1) “slave”
2) “172.10.3.60”
3) (integer) 6379
4) “connected”
5) (integer) 3430

kubectl exec -it -n public-service redis-5 bash

root@redis-5:/data# redis-cli -c

127.0.0.1:6379> ROLE

1) “master”
2) (integer) 3584
3) 1) 1) “172.10.3.61”
2) “6379”
3) “3570”

127.0.0.1:6379> CLUSTER NODES

aac2b3d320da67eedf3512ed0e38a1cdce5bc8fe 172.10.2.55:6379@16379 slave 7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 0 1592278859530 2 connected
2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 172.10.2.54:6379@16379 master – 0 1592278859000 1 connected 0-5461
c1dbaaef4a583e372c43eed52c22cd9ad7184d18 172.10.4.78:6379@16379 slave 2efad514b2f3c7fe4530dd6dc63c0df8ffdb793d 0 1592278859000 1 connected
524f03526a4b683d7d4de19296431810bfdc22cf 172.10.3.60:6379@16379 myself,master – 0 1592278857000 6 connected 10923-16383
7c4d60cf32685484ea6c5cb4493a937dfbf6b8a5 172.10.4.77:6379@16379 master – 0 1592278858021 2 connected 5462-10922
df5bc3c2e2851d63cdb9f762efde6e1b0d38efed 172.10.3.61:6379@16379 slave 524f03526a4b683d7d4de19296431810bfdc22cf 0 1592278859000 6 connected

可以看到，redis-2在重启之后变为slave，而它之前的slave——redis-5变为master，而且是新redis-2的master。

集群的主从切换没有问题。k8s部署redis cluster集群完成。

到此这篇关于k8s部署redis cluster集群的实现的文章就介绍到这了,更多相关k8s部署redis cluster内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持！

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数据运维技术 » k8s部署redis cluster集群的实现

分享到：

Redis 介绍

为什么要用Redis

什么是Redis Cluster集群

k8s以StatefulSet方式部署redis cluster集群：

部署nfs

创建pv

部署redis

初始化redis集群

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