13.1.k8s集群的七层代理-ingress资源(进阶知识)

2024-06-22 09:20

本文主要是介绍13.1.k8s集群的七层代理-ingress资源(进阶知识),希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

目录

一、ingress概述

1.前言

2.问题

3.ingress资源

二、ingress-nginx是什么

三、ingress-nginx 实现原理

四、部署ingress-nginx

1.获取部署文件 ingress-nginx.yaml

2.部署ingress-nginx

3.检查部署是否成功

五、编写使用Ingress样例代码

1.Ingress资源对象yaml文件

2.修改本地hosts 配置域名

3.浏览器访问后端方法

4.常见错误


示例代码:easy-paas: EasyPass平台  目录:docs/k8s

一、ingress概述

1.前言

k8s服务对外暴露有三种方式 NodePort,LoadBalancer,Ingress

Nodeport: 服务暴露需要在集群每个节点都开放一个同样的端口,通过nodtIp:nodePort来访问,如果服务数量多了,开放的端口就难以管理
LoadBalancer: 大部分情况下只适用于支持外部负载均衡器的云提供商(AWS,阿里云,华为云等)使用。每个服务都会由云服务提供一个IP作为入口,转发相应的流量,但每个LoadBlancer Service都会产生费用,成本比较高。如果想要在内网环境中使用就需要部署网络负载均衡器,比如MetalLB等组件,它主要提供两个功能:地址分配和外部通知。

  所以这次我们主要来介绍Ingress的部署和使用,Ingress可以把进入到集群内部的请求转发到集群中的一些服务上,从而可以把服务映射到集群外部。Ingress 能把集群内Service 配置成外网能够访问的 URL,流量负载均衡,提供基于域名访问的虚拟主机等。

2.问题

        1、当一个端口需要被多个服务使用的时候,就力不从心了,假设两个业务,都想要用443端口,那么就无法使用了;

        2、集群宿主机端口占用太多

        3、如果节点/虚拟机的IP地址发生变化,需要人工进行处理;

3.ingress资源

        ingress资源,是k8s中抽象的资源,给管理员提供暴露服务的入口“自定义”的方法,换句话说就是编辑网络暴露入口的规则;

        ingress资源,根据ingress生成具体的“路由规则”,同时借助SVC资源实现pod的负载均衡;

二、ingress-nginx是什么

ingress-nginx 在 kubernetes 中是一个具有七层协议(HTTP/HTTPS)的路由转发机制,通过策略以及结合具体提供转发服务的 Ingress Controller 来实现基于灵活的 ingress 策略定义的服务路由功能,ingress controller目前主要有两种:基于nginx服务的ingress controller和基于traefik的ingress controller,我们重点讲一下ingress-nginx。

k8s提供的ingress,github地址:https://github.com/kubernetes/ingress-nginx
nginx提供的ingress,github地址:https://github.com/nginxinc/kubernetes-ingress

ingress-nginx主要有两部分组成 Ingress和Ingress-controller

Ingress: 是k8s的一种资源对象,用来描述一个路由请求的yaml文件,将Nginx的配置抽象成一个
    Ingress对象,每添加一个新的服务只需写一个新的Ingress的yaml文件即可

Ingress-controller: 将新加入的Ingress转化成Nginx的配置文件并使之生效

三、ingress-nginx 实现原理

        Ingress-nginx简单的理解就是你原来需要改Nginx配置,然后配置各种域名对应哪个Service,现在变成每添加一个server就创建一个Ingress对象(yaml文件),不再需要去改Nginx,直接 部署yam就行了。Ingress Controller通过与Kubernetes API交互,动态感知集群中Ingress规则变化,然后读取他,按照他自己模板生成一段Nginx配置,再写到ingress-nginx-controller Pod里,最后reload 一下。

ingress具体的工作原理如下:

  1. 部署一个ingress资源对象,yaml文件写明了哪个域名对应k8s集群中的哪个service。
  2. ingress contronler通过与k8s的api进行交互,动态的去感知k8s集群中ingress服务规则的变化,然后读取它再根据ingress-controller中的nginx配置模板,生成一段对应的nginx配置。
  3. 把该配置动态的写到ingress-nginx-controller的pod里,该ingress-nginx-controller的pod里面运行着一个nginx服务,控制器会把生成的nginx配置写入到nginx的配置文件中,然后reload一下,使其配置生效,以此来达到域名分配置及动态更新的效果
  4. 浏览器请求先到ingress-nginx-controller 服务,再按照定义的ingress规则,转发到k8s集群中对应的service。

四、部署ingress-nginx

版本对应:GitHub - kubernetes/ingress-nginx: Ingress-NGINX Controller for KubernetesIngress-NGINX Controller for Kubernetes. Contribute to kubernetes/ingress-nginx development by creating an account on GitHub.icon-default.png?t=N7T8https://github.com/kubernetes/ingress-nginx

 ingress-nginx 部署文档地址:Installation Guide - Ingress-Nginx Controllericon-default.png?t=N7T8https://kubernetes.github.io/ingress-nginx/deploy/

1.获取部署文件 ingress-nginx.yaml

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.6.4/deploy/static/provider/cloud/deploy.yaml

有直接用部署的命令,但是yaml文件中有镜像因为网络的原因无法下载,所以需要先下载文件,进行替换

wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.6.4/deploy/static/provider/cloud/deploy.yaml

网络的原因,镜像修改为

# 原始镜像
registry.k8s.io/ingress-nginx/controller:v1.6.3@sha256:b92667e0afde1103b736e6a3f00dd75ae66eec4e71827d19f19f471699e909d2
registry.k8s.io/ingress-nginx/kube-webhook-certgen:v20220916-gd32f8c343@sha256:39c5b2e3310dc4264d638ad28d9d1d96c4cbb2b2dcfb52368fe4e3c63f61e10f# 修改为
registry.cn-hangzhou.aliyuncs.com/oslee-dockerhub/ingress-nginx-controller:v1.6.3
registry.cn-hangzhou.aliyuncs.com/oslee-dockerhub/kube-webhook-certgen:v20220916-gd32f8c343

修改ingress-nginx的暴露方式。官网默认的是LoadBalancer,如果想使用需要安装MetalLB,我们先修改成为NodePort方式。

直接使用已修改好的ingress-nginx.yaml

apiVersion: v1
kind: Namespace
metadata:labels:app.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxname: ingress-nginx
---
apiVersion: v1
automountServiceAccountToken: true
kind: ServiceAccount
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginxnamespace: ingress-nginx
---
apiVersion: v1
kind: ServiceAccount
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admissionnamespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginxnamespace: ingress-nginx
rules:- apiGroups:- ""resources:- namespacesverbs:- get- apiGroups:- ""resources:- configmaps- pods- secrets- endpointsverbs:- get- list- watch- apiGroups:- ""resources:- servicesverbs:- get- list- watch- apiGroups:- networking.k8s.ioresources:- ingressesverbs:- get- list- watch- apiGroups:- networking.k8s.ioresources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.ioresources:- ingressclassesverbs:- get- list- watch- apiGroups:- coordination.k8s.ioresourceNames:- ingress-nginx-leaderresources:- leasesverbs:- get- update- apiGroups:- coordination.k8s.ioresources:- leasesverbs:- create- apiGroups:- ""resources:- eventsverbs:- create- patch- apiGroups:- discovery.k8s.ioresources:- endpointslicesverbs:- list- watch- get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admissionnamespace: ingress-nginx
rules:- apiGroups:- ""resources:- secretsverbs:- get- create
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:app.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx
rules:- apiGroups:- ""resources:- configmaps- endpoints- nodes- pods- secrets- namespacesverbs:- list- watch- apiGroups:- coordination.k8s.ioresources:- leasesverbs:- list- watch- apiGroups:- ""resources:- nodesverbs:- get- apiGroups:- ""resources:- servicesverbs:- get- list- watch- apiGroups:- networking.k8s.ioresources:- ingressesverbs:- get- list- watch- apiGroups:- ""resources:- eventsverbs:- create- patch- apiGroups:- networking.k8s.ioresources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.ioresources:- ingressclassesverbs:- get- list- watch- apiGroups:- discovery.k8s.ioresources:- endpointslicesverbs:- list- watch- get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission
rules:- apiGroups:- admissionregistration.k8s.ioresources:- validatingwebhookconfigurationsverbs:- get- update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginxnamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admissionnamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:app.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
apiVersion: v1
data:allow-snippet-annotations: "true"
kind: ConfigMap
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-controllernamespace: ingress-nginx
---
apiVersion: v1
kind: Service
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-controllernamespace: ingress-nginx
spec:externalTrafficPolicy: LocalipFamilies:- IPv4ipFamilyPolicy: SingleStackports:- appProtocol: httpname: httpport: 80protocol: TCPtargetPort: httpnodePort: 80- appProtocol: httpsname: httpsport: 443protocol: TCPtargetPort: httpsselector:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxtype: NodePort
---
apiVersion: v1
kind: Service
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-controller-admissionnamespace: ingress-nginx
spec:ports:- appProtocol: httpsname: https-webhookport: 443targetPort: webhookselector:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxtype: ClusterIP
---
apiVersion: apps/v1
kind: Deployment
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-controllernamespace: ingress-nginx
spec:minReadySeconds: 0revisionHistoryLimit: 10selector:matchLabels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxtemplate:metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxspec:containers:- args:- /nginx-ingress-controller- --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller- --election-id=ingress-nginx-leader- --controller-class=k8s.io/ingress-nginx- --ingress-class=nginx- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller- --validating-webhook=:8443- --validating-webhook-certificate=/usr/local/certificates/cert- --validating-webhook-key=/usr/local/certificates/keyenv:- name: POD_NAMEvalueFrom:fieldRef:fieldPath: metadata.name- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespace- name: LD_PRELOADvalue: /usr/local/lib/libmimalloc.soimage: registry.cn-hangzhou.aliyuncs.com/oslee-dockerhub/ingress-nginx-controller:v1.6.3imagePullPolicy: IfNotPresentlifecycle:preStop:exec:command:- /wait-shutdownlivenessProbe:failureThreshold: 5httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1name: controllerports:- containerPort: 80name: httpprotocol: TCP- containerPort: 443name: httpsprotocol: TCP- containerPort: 8443name: webhookprotocol: TCPreadinessProbe:failureThreshold: 3httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1resources:requests:cpu: 100mmemory: 90MisecurityContext:allowPrivilegeEscalation: truecapabilities:add:- NET_BIND_SERVICEdrop:- ALLrunAsUser: 101volumeMounts:- mountPath: /usr/local/certificates/name: webhook-certreadOnly: truednsPolicy: ClusterFirstnodeSelector:kubernetes.io/os: linuxingress: "true"serviceAccountName: ingress-nginxterminationGracePeriodSeconds: 300volumes:- name: webhook-certsecret:secretName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission-createnamespace: ingress-nginx
spec:template:metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission-createspec:containers:- args:- create- --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc- --namespace=$(POD_NAMESPACE)- --secret-name=ingress-nginx-admissionenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespaceimage: registry.cn-hangzhou.aliyuncs.com/oslee-dockerhub/kube-webhook-certgen:v20220916-gd32f8c343imagePullPolicy: IfNotPresentname: createsecurityContext:allowPrivilegeEscalation: falsenodeSelector:kubernetes.io/os: linuxingress: "true"restartPolicy: OnFailuresecurityContext:fsGroup: 2000runAsNonRoot: truerunAsUser: 2000serviceAccountName: ingress-nginx-admission
---
apiVersion: batch/v1
kind: Job
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission-patchnamespace: ingress-nginx
spec:template:metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission-patchspec:containers:- args:- patch- --webhook-name=ingress-nginx-admission- --namespace=$(POD_NAMESPACE)- --patch-mutating=false- --secret-name=ingress-nginx-admission- --patch-failure-policy=Failenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespaceimage: registry.cn-hangzhou.aliyuncs.com/oslee-dockerhub/kube-webhook-certgen:v20220916-gd32f8c343imagePullPolicy: IfNotPresentname: patchsecurityContext:allowPrivilegeEscalation: falsenodeSelector:kubernetes.io/os: linuxingress: "true"restartPolicy: OnFailuresecurityContext:fsGroup: 2000runAsNonRoot: truerunAsUser: 2000serviceAccountName: ingress-nginx-admission
---
apiVersion: networking.k8s.io/v1
kind: IngressClass
metadata:labels:app.kubernetes.io/component: controllerapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: nginx
spec:controller: k8s.io/ingress-nginx
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:labels:app.kubernetes.io/component: admission-webhookapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/name: ingress-nginxapp.kubernetes.io/part-of: ingress-nginxapp.kubernetes.io/version: 1.6.3name: ingress-nginx-admission
webhooks:- admissionReviewVersions:- v1clientConfig:service:name: ingress-nginx-controller-admissionnamespace: ingress-nginxpath: /networking/v1/ingressesfailurePolicy: FailmatchPolicy: Equivalentname: validate.nginx.ingress.kubernetes.iorules:- apiGroups:- networking.k8s.ioapiVersions:- v1operations:- CREATE- UPDATEresources:- ingressessideEffects: None

2.部署ingress-nginx

# 可添加nodeSelector 部署至期望的节点上
kubectl label nodes k8s1 ingress=true
kubectl apply -f ingress-nginx.yaml

3.检查部署是否成功

kubectl get all -n ingress-nginx -owide

五、编写使用Ingress样例代码

1.Ingress资源对象yaml文件

# ingress 配置
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:name: easy-paas-adminnamespace: easy-paas
#  annotations:
#    nginx.ingress.kubernetes.io/rewrite-target: /
#    kubernetes.io/ingress.class: nginx
spec:ingressClassName: nginxrules:- host : "easy-paas.com"http :paths :- pathType : Prefixpath : /backend :service :name : easy-paas-adminport:number: 8001

2.修改本地hosts 配置域名

192.168.11.11 easy-paas.com

3.浏览器访问后端方法

4.常见错误

Error from server (InternalError): error when creating "easy-paas-admin.yaml": Internal error occurred: failed calling webhook "validate.nginx.ingress.kubernetes.io": failed to call webhook: Post "https://ingress-nginx-controller-admission.ingress-nginx.svc:443/networking/v1/ingresses?timeout=10s": dial tcp 10.200.140.179:443: connect: connection refused

查看

kubectl get validatingwebhookconfigurations

删除ingress-nginx-admission
kubectl delete -A ValidatingWebhookConfiguration ingress-nginx-admission

然后再执行

 kubectl apply -f easy-paas-admin.yaml
 

这篇关于13.1.k8s集群的七层代理-ingress资源(进阶知识)的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/1083885

相关文章

Spring Security 从入门到进阶系列教程

Spring Security 入门系列 《保护 Web 应用的安全》 《Spring-Security-入门(一):登录与退出》 《Spring-Security-入门(二):基于数据库验证》 《Spring-Security-入门(三):密码加密》 《Spring-Security-入门(四):自定义-Filter》 《Spring-Security-入门(五):在 Sprin

Java架构师知识体认识

源码分析 常用设计模式 Proxy代理模式Factory工厂模式Singleton单例模式Delegate委派模式Strategy策略模式Prototype原型模式Template模板模式 Spring5 beans 接口实例化代理Bean操作 Context Ioc容器设计原理及高级特性Aop设计原理Factorybean与Beanfactory Transaction 声明式事物

服务器集群同步时间手记

1.时间服务器配置(必须root用户) (1)检查ntp是否安装 [root@node1 桌面]# rpm -qa|grep ntpntp-4.2.6p5-10.el6.centos.x86_64fontpackages-filesystem-1.41-1.1.el6.noarchntpdate-4.2.6p5-10.el6.centos.x86_64 (2)修改ntp配置文件 [r

HDFS—集群扩容及缩容

白名单:表示在白名单的主机IP地址可以,用来存储数据。 配置白名单步骤如下: 1)在NameNode节点的/opt/module/hadoop-3.1.4/etc/hadoop目录下分别创建whitelist 和blacklist文件 (1)创建白名单 [lytfly@hadoop102 hadoop]$ vim whitelist 在whitelist中添加如下主机名称,假如集群正常工作的节

Hadoop集群数据均衡之磁盘间数据均衡

生产环境,由于硬盘空间不足,往往需要增加一块硬盘。刚加载的硬盘没有数据时,可以执行磁盘数据均衡命令。(Hadoop3.x新特性) plan后面带的节点的名字必须是已经存在的,并且是需要均衡的节点。 如果节点不存在,会报如下错误: 如果节点只有一个硬盘的话,不会创建均衡计划: (1)生成均衡计划 hdfs diskbalancer -plan hadoop102 (2)执行均衡计划 hd

Java进阶13讲__第12讲_1/2

多线程、线程池 1.  线程概念 1.1  什么是线程 1.2  线程的好处 2.   创建线程的三种方式 注意事项 2.1  继承Thread类 2.1.1 认识  2.1.2  编码实现  package cn.hdc.oop10.Thread;import org.slf4j.Logger;import org.slf4j.LoggerFactory

高效+灵活,万博智云全球发布AWS无代理跨云容灾方案!

摘要 近日,万博智云推出了基于AWS的无代理跨云容灾解决方案,并与拉丁美洲,中东,亚洲的合作伙伴面向全球开展了联合发布。这一方案以AWS应用环境为基础,将HyperBDR平台的高效、灵活和成本效益优势与无代理功能相结合,为全球企业带来实现了更便捷、经济的数据保护。 一、全球联合发布 9月2日,万博智云CEO Michael Wong在线上平台发布AWS无代理跨云容灾解决方案的阐述视频,介绍了

sqlite3 相关知识

WAL 模式 VS 回滚模式 特性WAL 模式回滚模式(Rollback Journal)定义使用写前日志来记录变更。使用回滚日志来记录事务的所有修改。特点更高的并发性和性能;支持多读者和单写者。支持安全的事务回滚,但并发性较低。性能写入性能更好,尤其是读多写少的场景。写操作会造成较大的性能开销,尤其是在事务开始时。写入流程数据首先写入 WAL 文件,然后才从 WAL 刷新到主数据库。数据在开始

在JS中的设计模式的单例模式、策略模式、代理模式、原型模式浅讲

1. 单例模式(Singleton Pattern) 确保一个类只有一个实例,并提供一个全局访问点。 示例代码: class Singleton {constructor() {if (Singleton.instance) {return Singleton.instance;}Singleton.instance = this;this.data = [];}addData(value)

搭建Kafka+zookeeper集群调度

前言 硬件环境 172.18.0.5        kafkazk1        Kafka+zookeeper                Kafka Broker集群 172.18.0.6        kafkazk2        Kafka+zookeeper                Kafka Broker集群 172.18.0.7        kafkazk3