statefulset特点
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参考技术A 稳定的、唯一的网络标识（Pod可以固定IP）。稳定的、持久的存储。
有序的、优雅的部署和伸缩。
有序的、优雅的删除和停止。
有序的、自动的滚动更新。
kubernetes 实现redis-statefulset集群
Kubernetes 通过statefulset部署redis cluster集群
部署redis集群方式的选择
- Statefulset
- Service&depolyment
对于redis,mysql这种有状态的服务,我们使用statefulset方式为首选.我们这边主要就是介绍statefulset这种方式
ps:
statefulset 的设计原理模型:
拓扑状态.应用的多个实例之间不是完全对等的关系,这个应用实例的启动必须按照某些顺序启动,比如应用的
主节点 A 要先于从节点 B 启动。而如果你把 A 和 B 两个Pod删除掉,他们再次被创建出来是也必须严格按
照这个顺序才行,并且,新创建出来的Pod,必须和原来的Pod的网络标识一样,这样原先的访问者才能使用同样
的方法,访问到这个新的Pod
存储状态:应用的多个实例分别绑定了不同的存储数据.对于这些应用实例来说,Pod A第一次读取到的数据,和
隔了十分钟之后再次读取到的数据,应该是同一份,哪怕在此期间Pod A被重新创建过.一个数据库应用的多个
存储实例部署
安装NFS(共享存储)
因为k8s上pod是飘忽不定的,所以我们肯定需要用一个共享存储来提供存储,这样不管pod漂移到哪个节点都能访问这个共享的数据卷.我这个地方先使用NFS来做共享存储,后期可以 选择别的替换
yum -y install nfs-utils rpcbind
vim /etc/exports
/usr/local/kubernetes/redis/pv1 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv2 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv3 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv4 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv5 0.0.0.0/0(rw,all_squash)
/usr/local/kubernetes/redis/pv6 0.0.0.0/0(rw,all_squash)
mkdir -p /usr/local/kubernetes/redis/pv{1..6}
chmod 777 /usr/local/kubernetes/redis/pv{1..6}后期我们可以写成域名 通配符
启动服务
systemctl enable nfs
systemctl enable rpcbind
systemctl start nfs
systemctl start rpcbind创建pv
创建6个pv 一会供pvc挂载使用
vim pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv1
spec:
capacity:
storage: 200M #磁盘大小200M
accessModes:
- ReadWriteMany #多客户可读写
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv1"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-vp2
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv2"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv3
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv3"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv4
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv4"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv5
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv5"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv6
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: NFS服务器地址
path: "/usr/local/kubernetes/redis/pv6"字段说明:
apiversion: api版本
kind: 这个yaml是生成pv的
metadata: 元数据
spec.capacity: 进行资源限制的
spec.accessmodes: 访问模式(读写模式)
spec.nfs: 这个pv卷名是通过nfs提供的
创建pv
kubectl create -f pv.yaml
kubectl get pv #查看创建的pv创建configmap,用来存放redis的配置文件
因为redis的配置文件里面可能会改变,所以我们使用configmap这种方式给配置文件弄出来,我们后期改的时候就不需要没改次配置文件就从新生成一个docker images包了
appendonly yes #开启Redis的AOF持久化
cluster-enabled yes #集群模式打开
cluster-config-file /var/lib/redis/nodes.conf #下面说明
cluster-node-timeout 5000 #节点超时时间
dir /var/lib/redis #AOF持久化文件存在的位置
port 6379 #开启的端口cluster-conf-file: 选项设定了保存节点配置文件的路径,如果这个配置文件不存在,每个节点在启动的时候都为他自身指定了一个新的ID存档到这个文件中,实例会一直使用同一个ID,在集群中保持一个独一无二的(Unique)名字.每个节点都是用ID而不是IP或者端口号来记录其他节点,因为在k8s中,IP地址是不固定的,而这个独一无二的标识符(Identifier)则会在节点的整个生命周期中一直保持不变,我们这个文件里面存放的是节点ID
创建名为redis-conf的Configmap：
kubectl create configmap redis-conf --from-file=redis.conf查看:
[[email protected] ~]# kubectl get cm
NAME DATA AGE
redis-conf 1 22h
[[email protected] ~]# kubectl describe cm redis-conf
Name: redis-conf
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
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
Events: <none>创建headless service
Headless service是StatefulSet实现稳定网络标识的基础，我们需要提前创建。准备文件headless-service.yml如下：
apiVersion: v1
kind: Service
metadata:
name: redis-service
labels:
app: redis
spec:
ports:
- name: redis-port
port: 6379
clusterIP: None
selector:
app: redis
appCluster: redis-cluster创建：
kubectl create -f headless-service.yml查看：
[[email protected] redis]# kubectl get svc redis-service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
redis-service ClusterIP None <none> 6379/TCP 53s可以看到，服务名称为redis-service，其CLUSTER-IP为None，表示这是一个“无头”服务。
创建redis集群节点
这是本文的核心内容,创建redis.yaml文件
[[email protected] ~]# cat /home/docker/redis/redis.yml
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
name: redis-app
spec:
serviceName: "redis-service"
replicas: 6
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"
command:
- "redis-server" #redis启动命令
args:
- "/etc/redis/redis.conf" #redis-server后面跟的参数,换行代表空格
- "--protected-mode" #允许外网访问
- "no"
# command: redis-server /etc/redis/redis.conf --protected-mode no
resources: #资源
requests: #请求的资源
cpu: "100m" #m代表千分之,相当于0.1 个cpu资源
memory: "100Mi" #内存100m大小
ports:
- name: redis
containerPort: 6379
protocol: "TCP"
- name: cluster
containerPort: 16379
protocol: "TCP"
volumeMounts:
- name: "redis-conf" #挂载configmap生成的文件
mountPath: "/etc/redis" #挂载到哪个路径下
- name: "redis-data" #挂载持久卷的路径
mountPath: "/var/lib/redis"
volumes:
- name: "redis-conf" #引用configMap卷
configMap:
name: "redis-conf"
items:
- key: "redis.conf" #创建configMap指定的名称
path: "redis.conf" #里面的那个文件--from-file参数后面的文件
volumeClaimTemplates: #进行pvc持久卷声明,
- metadata:
name: redis-data
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 200MPodAntiAffinity:表示反亲和性，其决定了某个pod不可以和哪些Pod部署在同一拓扑域，可以用于将一个服务的POD分散在不同的主机或者拓扑域中，提高服务本身的稳定性。matchExpressions:规定了Redis Pod要尽量不要调度到包含app为redis的Node上，也即是说已经存在Redis的Node上尽量不要再分配Redis Pod了.
另外，根据StatefulSet的规则，我们生成的Redis的6个Pod的hostname会被依次命名为$(statefulset名称)-$(序号)，如下图所示：
[[email protected] ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
redis-app-0 1/1 Running 0 40m 10.42.2.17 192.168.1.21 <none>
redis-app-1 1/1 Running 0 40m 10.42.0.15 192.168.1.114 <none>
redis-app-2 1/1 Running 0 40m 10.42.1.13 192.168.1.20 <none>
redis-app-3 1/1 Running 0 40m 10.42.2.18 192.168.1.21 <none>
redis-app-4 1/1 Running 0 40m 10.42.0.16 192.168.1.114 <none>
redis-app-5 1/1 Running 0 40m 10.42.1.14 192.168.1.20 <none>如上，可以看到这些Pods在部署时是以{0..N-1}的顺序依次创建的。注意，直到redis-app-0状态启动后达到Running状态之后，redis-app-1 才开始启动。
同时，每个Pod都会得到集群内的一个DNS域名，格式为$(podname).$(service name).$(namespace).svc.cluster.local，也即是：
redis-app-0.redis-service.default.svc.cluster.local
redis-app-1.redis-service.default.svc.cluster.local
...以此类推...在K8S集群内部，这些Pod就可以利用该域名互相通信。我们可以使用busybox镜像的nslookup检验这些域名:
[[email protected] ~]# kubectl run -i --tty --image busybox dns-test --restart=Never --rm /bin/sh
If you don‘t see a command prompt, try pressing enter.
/ # nslookup redis-app-1.redis-service.default.svc.cluster.local
Server: 10.43.0.10
Address: 10.43.0.10:53
Name: redis-app-1.redis-service.default.svc.cluster.local
Address: 10.42.0.15
*** Can‘t find redis-app-1.redis-service.default.svc.cluster.local: No answer
/ # nslookup redis-app-0.redis-service.default.svc.cluster.local
Server: 10.43.0.10
Address: 10.43.0.10:53
Name: redis-app-0.redis-service.default.svc.cluster.local
Address: 10.42.2.17可以看到， redis-app-0的IP为10.42.2.17。当然，若Redis Pod迁移或是重启（我们可以手动删除掉一个Redis Pod来测试），则IP是会改变的，但Pod的域名、SRV records、A record都不会改变。
另外可以发现，我们之前创建的pv都被成功绑定了：
[[email protected] ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv1 200M RWX Retain Bound default/redis-data-redis-app-2 1h
nfs-pv2 200M RWX Retain Bound default/redis-data-redis-app-3 1h
nfs-pv3 200M RWX Retain Bound default/redis-data-redis-app-4 1h
nfs-pv4 200M RWX Retain Bound default/redis-data-redis-app-5 1h
nfs-pv5 200M RWX Retain Bound default/redis-data-redis-app-0 1h
nfs-pv6 200M RWX Retain Bound default/redis-data-redis-app-1 1h初始化redis集群
创建好6个Redis Pod后，我们还需要利用常用的Redis-tribe工具进行集群的初始化。
创建centos容器
由于Redis集群必须在所有节点启动后才能进行初始化，而如果将初始化逻辑写入Statefulset中，则是一件非常复杂而且低效的行为。这里，本人不得不称赞一下原项目作者的思路，值得学习。也就是说，我们可以在K8S上创建一个额外的容器，专门用于进行K8S集群内部某些服务的管理控制。
这里，我们专门启动一个Ubuntu的容器，可以在该容器中安装Redis-tribe，进而初始化Redis集群，执行：
kubectl run -i --tty centos --image=centos --restart=Never /bin/bash成功后，我们可以进入centos容器中，原项目要求执行如下命令安装基本的软件环境:
cat >> /etc/yum.repo.d/epel.repo<<‘EOF‘
[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
baseurl=https://mirrors.tuna.tsinghua.edu.cn/epel/7/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
EOF初始化redis集群
首先，我们需要安装redis-trib(redis集群命令行工具)：
yum -y install redis-trib.noarch bind-utils-9.9.4-72.el7.x86_64然后创建一主一从的集群节点信息：
redis-trib create --replicas 1 `dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-1.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-2.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-3.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-4.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-5.redis-service.default.svc.cluster.local`:6379
#create: 创建一个新的集群
#--replicas 1 : 创建的集群中每个主节点分配一个从节点,达到3主3从
#后面跟的就是redis实例所在的位置如上，命令dig +short redis-app-0.redis-service.default.svc.cluster.local用于将Pod的域名转化为IP，这是因为redis-trib不支持域名来创建集群。
执行完成后redis-trib会打印一份预配置文件给你查看,如果没问题输入yes,redis-trib就会把这份配置文件应用到集群中
>>> Creating cluster
>>> Performing hash slots allocation on 6 nodes...
Using 3 masters:
10.42.2.17:6379
10.42.0.15:6379
10.42.1.13:6379
Adding replica 10.42.2.18:6379 to 10.42.2.17:6379
Adding replica 10.42.0.16:6379 to 10.42.0.15:6379
Adding replica 10.42.1.14:6379 to 10.42.1.13:6379
M: 4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379
slots:0-5460 (5461 slots) master
M: 505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:6379
slots:5461-10922 (5462 slots) master
M: 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:6379
slots:10923-16383 (5461 slots) master
S: 366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:6379
replicates 4676f8913cdcd1e256db432531c80591ae6c5fc3
S: cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:6379
replicates 505f3e126882c0c5115885e54f9b361bc7e74b97
S: e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:6379
replicates 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f
Can I set the above configuration? (type ‘yes‘ to accept):输入yes后开始创建集群
>>> 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 10.42.2.17:6379)
M: 4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:6379
slots:0-5460 (5461 slots) master
1 additional replica(s)
M: 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:[email protected]
slots:10923-16383 (5461 slots) master
1 additional replica(s)
S: e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:[email protected]
slots: (0 slots) slave
replicates 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f
S: 366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:[email protected]
slots: (0 slots) slave
replicates 4676f8913cdcd1e256db432531c80591ae6c5fc3
M: 505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:[email protected]
slots:5461-10922 (5462 slots) master
1 additional replica(s)
S: cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:[email protected]
slots: (0 slots) slave
replicates 505f3e126882c0c5115885e54f9b361bc7e74b97
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.最后一句表示集群中的16384个槽都有至少一个主节点在处理， 集群运作正常.
至此，我们的Redis集群就真正创建完毕了，连到任意一个Redis Pod中检验一下：
[email protected] ~]# kubectl exec -it redis-app-2 /bin/bash
[email protected]:/data# /usr/local/bin/redis-cli -c
127.0.0.1:6379> cluster info
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:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:186
cluster_stats_messages_pong_sent:199
cluster_stats_messages_sent:385
cluster_stats_messages_ping_received:194
cluster_stats_messages_pong_received:186
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:385
127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.13:[email protected] master - 0 1550555011000 3 connected 10923-16383
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:[email protected] slave 589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 0 1550555011512 6 connected
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:[email protected] slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550555010507 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:[email protected] master - 0 1550555011000 2 connected 5461-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:[email protected] slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550555011713 5 connected
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:[email protected] myself,master - 0 1550555010000 1 connected 0-5460另外，还可以在NFS上查看Redis挂载的数据：
[[email protected] ~]# tree /usr/local/kubernetes/redis/
/usr/local/kubernetes/redis/
├── pv1
│ ├── appendonly.aof
│ ├── dump.rdb
│ └── nodes.conf
├── pv2
│ ├── appendonly.aof
│ ├── dump.rdb
│ └── nodes.conf
├── pv3
│ ├── appendonly.aof
│ ├── dump.rdb
│ └── nodes.conf
├── pv4
│ ├── appendonly.aof
│ ├── dump.rdb
│ └── nodes.conf
├── pv5
│ ├── appendonly.aof
│ ├── dump.rdb
│ └── nodes.conf
└── pv6
├── appendonly.aof
├── dump.rdb
└── nodes.conf
6 directories, 18 files创建用于访问service
前面我们创建了用于实现statefulset的headless service,但该service没有cluster IP,因此不能用于外界访问.所以我们还需要创建一个service,专用于为Redis集群提供访问和负载均衡:
piVersion: v1
kind: Service
metadata:
name: redis-access-service
labels:
app: redis
spec:
ports:
- name: redis-port
protocol: "TCP"
port: 6379
targetPort: 6379
selector:
app: redis
appCluster: redis-cluster如上，该Service名称为 redis-access-service，在K8S集群中暴露6379端口，并且会对labels name为app: redis或appCluster: redis-cluster的pod进行负载均衡。
创建后查看：
[[email protected] ~]# kubectl get svc redis-access-service -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
redis-access-service ClusterIP 10.43.40.62 <none> 6379/TCP 47m app=redis,appCluster=redis-cluster如上,在k8s集群中,所有应用都可以通过10.43.40.62:6379来访问redis集群,当然，为了方便测试，我们也可以为Service添加一个NodePort映射到物理机上，待测试。
测试主从切换
在K8S上搭建完好Redis集群后，我们最关心的就是其原有的高可用机制是否正常。这里，我们可以任意挑选一个Master的Pod来测试集群的主从切换机制，如redis-app-2：
[[email protected] ~]# kubectl get pods redis-app-2 -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
redis-app-2 1/1 Running 0 1h 10.42.1.13 192.168.1.20 <none>进入redis-app-2查看：
[[email protected] ~]# kubectl exec -it redis-app-2 /bin/bash
[email protected]:/data# redis-cli
127.0.0.1:6379> role
1) "master"
2) (integer) 9478
3) 1) 1) "10.42.1.14"
2) "6379"
3) "9478"如上可以看到，其为master，slave为10.42.1.14即redis-app-5。
接着，我们手动删除redis-app-2：
[[email protected] ~]# kubectl delete pods redis-app-2
pod "redis-app-2" deleted
[[email protected] ~]# kubectl get pods redis-app-2 -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
redis-app-2 1/1 Running 0 19s 10.42.1.15 192.168.1.20 <none>如上，IP改变为10.42.1.15。我们再进入redis-app-2内部查看：
[[email protected] ~]# kubectl exec -it redis-app-2 /bin/bash
[email protected]:/data# redis-cli
127.0.0.1:6379> ROLE
1) "slave"
2) "10.42.1.14"
3) (integer) 6379
4) "connected"
5) (integer) 9688如上，redis-app-2变成了slave，从属于它之前的从节点10.42.1.14即redis-app-5。
redis动态扩容
我们现在这个集群中有6个节点三主三从,我现在添加两个pod节点,达到4主4从
添加nfs共享目录
cat >> /etc/exports <<‘EOF‘
/usr/local/kubernetes/redis/pv7 192.168.0.0/16(rw,all_squash)
/usr/local/kubernetes/redis/pv8 192.168.0.0/16(rw,all_squash)
EOF
systemctl restart nfs rpcbind
[[email protected] ~]# mkdir /usr/local/kubernetes/redis/pv{7..8}
[[email protected] ~]# chmod 777 /usr/local/kubernetes/redis/*更新pv的yml文件,也可以自己在重新创建一个,这边选择自己新建
[[email protected] redis]# cat pv_add.yml
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv7
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: 192.168.1.253
path: "/usr/local/kubernetes/redis/pv7"
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv8
spec:
capacity:
storage: 200M
accessModes:
- ReadWriteMany
nfs:
server: 192.168.1.253
path: "/usr/local/kubernetes/redis/pv8"创建查看pv:
[[email protected] redis]# kubectl create -f pv_add.yml
persistentvolume/nfs-pv7 created
persistentvolume/nfs-pv8 created
[[email protected] redis]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv1 200M RWX Retain Bound default/redis-data-redis-app-1 2h
nfs-pv2 200M RWX Retain Bound default/redis-data-redis-app-2 2h
nfs-pv3 200M RWX Retain Bound default/redis-data-redis-app-4 2h
nfs-pv4 200M RWX Retain Bound default/redis-data-redis-app-5 2h
nfs-pv5 200M RWX Retain Bound default/redis-data-redis-app-0 2h
nfs-pv6 200M RWX Retain Bound default/redis-data-redis-app-3 2h
nfs-pv7 200M RWX Retain Available 7s
nfs-pv8 200M RWX Retain Available 7s添加redis节点
更改redis的yml文件里面的replicas:字段,把这个字段改为8,然后升级运行
[[email protected] redis]# kubectl apply -f redis.yml
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
statefulset.apps/redis-app configured
[[email protected] redis]# kubectl get pods
NAME READY STATUS RESTARTS AGE
redis-app-0 1/1 Running 0 2h
redis-app-1 1/1 Running 0 2h
redis-app-2 1/1 Running 0 19m
redis-app-3 1/1 Running 0 2h
redis-app-4 1/1 Running 0 2h
redis-app-5 1/1 Running 0 2h
redis-app-6 1/1 Running 0 57s
redis-app-7 1/1 Running 0 30s添加集群节点
[[email protected] redis]#kubectl exec -it centos /bin/bash
[[email protected] /]# redis-trib add-node `dig +short redis-app-6.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379
[[email protected] /]# redis-trib add-node `dig +short redis-app-7.redis-service.default.svc.cluster.local`:6379 `dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379add-node后面跟的是新节点的信息,后面是以前集群中的任意 一个节点
查看添加redis节点是否正常
[[email protected] redis]# kubectl exec -it redis-app-0 bash
[email protected]:/data# redis-cli
127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.15:[email protected] slave e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 0 1550564776000 7 connected
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:[email protected] master - 0 1550564776000 7 connected 10923-16383
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:[email protected] slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550564777051 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:[email protected] master - 0 1550564776851 2 connected 5461-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:[email protected] slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550564775000 5 connected
e4697a7ba460ae2979692116b95fbe1f2c8be018 10.42.0.20:[email protected] master - 0 1550564776549 0 connected
246c79682e6cc78b4c2c28d0e7166baf47ecb265 10.42.2.23:[email protected] master - 0 1550564776548 8 connected
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:[email protected] myself,master - 0 1550564775000 1 connected 0-5460重新分配哈希槽
redis-trib.rb reshard `dig +short redis-app-0.redis-service.default.svc.cluster.local`:6379
## 输入要移动的哈希槽
## 移动到哪个新的master节点(ID)
## all 是从所有master节点上移动查看对应的节点信息
127.0.0.1:6379> cluster nodes
589b4f4f908a04f56d2ab9cd6fd0fd25ea14bb8f 10.42.1.15:[email protected] slave e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 0 1550566162000 7 connected
e9f1f704ff7c8f060d6b39e23be9cd8e55cb2e46 10.42.1.14:[email protected] master - 0 1550566162909 7 connected 11377-16383
366abbba45d3200329a5c6305fbcec9e29b50c80 10.42.2.18:[email protected] slave 4676f8913cdcd1e256db432531c80591ae6c5fc3 0 1550566161600 4 connected
505f3e126882c0c5115885e54f9b361bc7e74b97 10.42.0.15:[email protected] master - 0 1550566161902 2 connected 5917-10922
cee3a27cc27635da54d94f16f6375cd4acfe6c30 10.42.0.16:[email protected] slave 505f3e126882c0c5115885e54f9b361bc7e74b97 0 1550566162506 5 connected
246c79682e6cc78b4c2c28d0e7166baf47ecb265 10.42.2.23:[email protected] master - 0 1550566161600 8 connected 0-453 5461-5916 10923-11376
4676f8913cdcd1e256db432531c80591ae6c5fc3 10.42.2.17:[email protected] myself,master - 0 1550566162000 1以上是关于statefulset特点的主要内容，如果未能解决你的问题，请参考以下文章
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