1. 需求背景与万里安全数据库软件GreatDB分布式部署模式介绍
1.1 需求背景
混沌测试是检测分布式系统不确定性、建立系统弹性信心的一种非常好的方式，因此我们采用开源工具Chaos Mesh来做GreatDB分布式集群的混沌测试。
1.2 万里安全数据库软件GreatDB分布式部署模式介绍
万里安全数据库软件GreatDB 是一款关系型数据库软件，同时支持集中式和分布式的部署方式，本文涉及的是分布式部署方式。
分布式部署模式采用shared-nothing架构；通过数据冗余与副本管理确保数据库无单点故障；数据sharding与分布式并行计算实现数据库系统高性能；可无限制动态扩展数据节点，满足业务需要。
整体架构如下图所示：
2. 环境准备
2.1 Chaos Mesh安装
在安装Chaos Mesh之前请确保已经预先安装了helm，docker，并准备好了一个kubernetes环境。
- 使用Helm安装
1）在 Helm 仓库中添加 Chaos Mesh 仓库：
helm repo add chaos-mesh https://charts.chaos-mesh.org
2）查看可以安装的 Chaos Mesh 版本：
helm search repo chaos-mesh
3）创建安装 Chaos Mesh 的命名空间：
kubectl create ns chaos-testing
4）在docker环境下安装Chaos Mesh：
helm install chaos-mesh chaos-mesh/chaos-mesh -n=chaos-testing
- 验证安装
执行以下命令查看Chaos Mesh的运行情况：
kubectl get pod -n chaos-testing
下面是预期输出：
NAME READY STATUS RESTARTS AGEchaos-controller-manager-d7bc9ccb5-dbccq 1/1 Running 0 26dchaos-daemon-pzxc7 1/1 Running 0 26dchaos-dashboard-5887f7559b-kgz46 1/1 Running 1 26d
如果3个pod的状态都是Running，表示 Chaos Mesh 已经成功安装。
2.2 准备测试需要的镜像
2.2.1 准备mysql镜像
一般情况下，mysql使用官方5.7版本的镜像，mysql监控采集器使用的是mysqld-exporter，也可以直接从docker hub下载：
docker pull mysql:5.7docker pull prom/mysqld-exporter
2.2.2 准备zookeeper镜像
zookeeper使用的是官方3.5.5版本镜像，zookeeper组件涉及的监控有jmx-prometheus-exporter 和zookeeper-exporter，均从docker hub下载：
docker pull zookeeper:3.5.5docker pull sscaling/jmx-prometheus-exporterdocker pull josdotso/zookeeper-exporter
2.2.3 准备GreatDB镜像
选择一个GreatDB的tar包，将其解压得到一个./greatdb目录，再将greatdb-service-docker.sh文件拷贝到这个解压出来的./greatdb目录里：
cp greatdb-service-docker.sh ./greatdb/
将greatdb Dockerfile放到./greatdb文件夹的同级目录下，然后执行以下命令构建GreatDB镜像：
docker build -t greatdb/greatdb:tag2021 .
2.2.4 准备GreatDB分布式集群部署/清理的镜像
下载集群部署脚本cluster-setup,集群初始化脚本init-zk 以及集群helm charts包（可咨询4.0开发/测试组获取）
将上述材料放在同一目录下，编写如下Dockerfile:
FROM debian:buster-slim as init-zkCOPY ./init-zk /root/init-zkRUN chmod +x /root/init-zkFROM debian:buster-slim as cluster-setup# Set aliyun repo for speedRUN sed -i 's/deb.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.list && sed -i 's/security.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.listRUN apt-get -y update && apt-get -y install curl wgetRUN curl -L https://storage.googleapis.com/kubernetes-release/release/v1.20.1/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl && chmod +x /usr/local/bin/kubectl && mkdir /root/.kube && wget https://get.helm.sh/helm-v3.5.3-linux-amd64.tar.gz && tar -zxvf helm-v3.5.3-linux-amd64.tar.gz && mv linux-amd64/helm /usr/local/bin/helmCOPY ./config /root/.kube/COPY ./helm /helmCOPY ./cluster-setup /
执行以下命令构建所需镜像：
docker build --target init-zk -t greatdb/initzk:latest .docker build --target cluster-setup -t greatdb/cluster-setup:v1 .
2.2.5 准备测试用例的镜像
目前测试支持的用例有：bank,bank2,pbank,tpcc,flashback等，每个用例都是一个可执行文件。
以flashback测例为例构建测试用例的镜像，先将用例下载到本地，在用例的同一目录下编写如下内容的Dockerfile：
FROM debian:buster-slimCOPY ./flashback /RUN cd / && chmod +x ./flashback
执行以下命令构建测试用例镜像：
docker build -t greatdb/testsuite-flashback:v1 .
2.3 将准备好的镜像上传到私有仓库中
创建私有仓库和上传镜像操作请参考：https://zhuanlan.zhihu.com/p/78543733
3. Chaos Mesh的使用
3.1 搭建GreatDB分布式集群
在上一章2.2.4 中cluster-setup目录下执行以下命令块去搭建测试集群：
./cluster-setup -clustername=c0 -namespace=test -enable-monitor=true -mysql-image=mysql:5.7 -mysql-replica=3 -mysql-auth=1 -mysql-normal=1 -mysql-global=1 -mysql-partition=1 -zookeeper-repository=zookeeper -zookeeper-tag=3.5.5 -zookeeper-replica=3 -greatdb-repository=greatdb/greatdb -greatdb-tag=tag202110 -greatdb-replica=3 -greatdb-serviceHost=172.16.70.249
输出信息：
liuxinle@liuxinle-OptiPlex-5060:~/k8s/cluster-setup$ ./cluster-setup > -clustername=c0 > -namespace=test > -enable-monitor=true > -mysql-image=mysql:5.7 > -mysql-replica=3 > -mysql-auth=1 > -mysql-normal=1 > -mysql-global=1 > -mysql-partition=1 > -zookeeper-repository=zookeeper > -zookeeper-tag=3.5.5 > -zookeeper-replica=3 > -greatdb-repository=greatdb/greatdb > -greatdb-tag=tag202110 > -greatdb-replica=3 > -greatdb-serviceHost=172.16.70.249INFO[2021-10-14T10:41:52+08:00] SetUp the cluster ... NameSpace=testINFO[2021-10-14T10:41:52+08:00] create namespace ... INFO[2021-10-14T10:41:57+08:00] copy helm chart templates ... INFO[2021-10-14T10:41:57+08:00] setup ... Component=MySQLINFO[2021-10-14T10:41:57+08:00] exec helm install and update greatdb-cfg.yaml ... INFO[2021-10-14T10:42:00+08:00] waiting mysql pods running ... INFO[2021-10-14T10:44:27+08:00] setup ... Component=ZookeeperINFO[2021-10-14T10:44:28+08:00] waiting zookeeper pods running ... INFO[2021-10-14T10:46:59+08:00] update greatdb-cfg.yaml INFO[2021-10-14T10:46:59+08:00] setup ... Component=greatdbINFO[2021-10-14T10:47:00+08:00] waiting greatdb pods running ... INFO[2021-10-14T10:47:21+08:00] waiting cluster running ... INFO[2021-10-14T10:47:27+08:00] waiting prometheus server running... INFO[2021-10-14T10:47:27+08:00] Dump Cluster Info INFO[2021-10-14T10:47:27+08:00] SetUp success. ClusterName=c0 NameSpace=test
执行如下命令，查看集群pod状态：
kubectl get pod -n test -o wide
输出信息：
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATESc0-auth0-mysql-0 2/2 Running 0 10m 10.244.87.18 liuxinle-optiplex-5060 c0-auth0-mysql-1 2/2 Running 0 9m23s 10.244.87.54 liuxinle-optiplex-5060 c0-auth0-mysql-2 2/2 Running 0 8m39s 10.244.87.57 liuxinle-optiplex-5060 c0-greatdb-0 2/2 Running 1 5m3s 10.244.87.58 liuxinle-optiplex-5060 c0-greatdb-1 2/2 Running 0 4m57s 10.244.87.20 liuxinle-optiplex-5060 c0-greatdb-2 2/2 Running 0 4m50s 10.244.87.47 liuxinle-optiplex-5060 c0-glob0-mysql-0 2/2 Running 0 10m 10.244.87.51 liuxinle-optiplex-5060 c0-glob0-mysql-1 2/2 Running 0 9m23s 10.244.87.41 liuxinle-optiplex-5060 c0-glob0-mysql-2 2/2 Running 0 8m38s 10.244.87.60 liuxinle-optiplex-5060 c0-nor0-mysql-0 2/2 Running 0 10m 10.244.87.29 liuxinle-optiplex-5060 c0-nor0-mysql-1 2/2 Running 0 9m29s 10.244.87.4 liuxinle-optiplex-5060 c0-nor0-mysql-2 2/2 Running 0 8m45s 10.244.87.25 liuxinle-optiplex-5060 c0-par0-mysql-0 2/2 Running 0 10m 10.244.87.55 liuxinle-optiplex-5060 c0-par0-mysql-1 2/2 Running 0 9m26s 10.244.87.13 liuxinle-optiplex-5060 c0-par0-mysql-2 2/2 Running 0 8m42s 10.244.87.21 liuxinle-optiplex-5060 c0-prometheus-server-6697649b76-fkvh9 2/2 Running 0 4m36s 10.244.87.37 liuxinle-optiplex-5060 c0-zookeeper-0 1/1 Running 1 7m35s 10.244.87.44 liuxinle-optiplex-5060 c0-zookeeper-1 1/1 Running 0 6m41s 10.244.87.30 liuxinle-optiplex-5060 c0-zookeeper-2 1/1 Running 0 6m10s 10.244.87.49 liuxinle-optiplex-5060 c0-zookeeper-initzk-7hbfs 0/1 Completed 0 7m35s 10.244.87.17 liuxinle-optiplex-5060
看到c0-zookeeper-initzk-7hbfs的状态是Completed，其他pod的状态为Running，表示集群搭建成功。
3.2 在GreatDB分布式集群中使用Chaos Mesh做混沌测试
Chaos Mesh在kubernetes环境支持注入的故障类型包括：模拟Pod故障、模拟网络故障、模拟压力场景等，这里我们以模拟Pod故障中的pod-kill为例。
将实验配置写入到文件中 pod-kill.yaml，内容示例如下：
apiVersion: chaos-mesh.org/v1alpha1kind: PodChaos # 要注入的故障类型metadata: name: pod-failure-example namespace: test # 测试集群pod所在的namespacespec: action: pod-kill # 要注入的具体故障类型 mode: all # 指定实验的运行方式，all（表示选出所有符合条件的 Pod） duration: '30s' # 指定实验的持续时间 selector: labelSelectors: "app.kubernetes.io/component": "greatdb" # 指定注入故障目标pod的标签，通过kubectl describe pod c0-greatdb-1 -n test 命令返回结果中Labels后的内容得到
创建故障实验，命令如下：
kubectl create -n test -f pod-kill.yaml
创建完故障实验之后，执行命令 kubectl get pod -n test -o wide 结果如下：
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATESc0-auth0-mysql-0 2/2 Running 0 14m 10.244.87.18 liuxinle-optiplex-5060 c0-auth0-mysql-1 2/2 Running 0 14m 10.244.87.54 liuxinle-optiplex-5060 c0-auth0-mysql-2 2/2 Running 0 13m 10.244.87.57 liuxinle-optiplex-5060 c0-greatdb-0 0/2 ContainerCreating 0 2s liuxinle-optiplex-5060 c0-greatdb-1 0/2 ContainerCreating 0 2s liuxinle-optiplex-5060 c0-glob0-mysql-0 2/2 Running 0 14m 10.244.87.51 liuxinle-optiplex-5060 c0-glob0-mysql-1 2/2 Running 0 14m 10.244.87.41 liuxinle-optiplex-5060 c0-glob0-mysql-2 2/2 Running 0 13m 10.244.87.60 liuxinle-optiplex-5060 c0-nor0-mysql-0 2/2 Running 0 14m 10.244.87.29 liuxinle-optiplex-5060 c0-nor0-mysql-1 2/2 Running 0 14m 10.244.87.4 liuxinle-optiplex-5060 c0-nor0-mysql-2 2/2 Running 0 13m 10.244.87.25 liuxinle-optiplex-5060 c0-par0-mysql-0 2/2 Running 0 14m 10.244.87.55 liuxinle-optiplex-5060 c0-par0-mysql-1 2/2 Running 0 14m 10.244.87.13 liuxinle-optiplex-5060 c0-par0-mysql-2 2/2 Running 0 13m 10.244.87.21 liuxinle-optiplex-5060 c0-prometheus-server-6697649b76-fkvh9 2/2 Running 0 9m24s 10.244.87.37 liuxinle-optiplex-5060 c0-zookeeper-0 1/1 Running 1 12m 10.244.87.44 liuxinle-optiplex-5060 c0-zookeeper-1 1/1 Running 0 11m 10.244.87.30 liuxinle-optiplex-5060 c0-zookeeper-2 1/1 Running 0 10m 10.244.87.49 liuxinle-optiplex-5060 c0-zookeeper-initzk-7hbfs 0/1 Completed 0 12m 10.244.87.17 liuxinle-optiplex-5060
可以看到有带greatdb名字的pod正在被重启，说明注入故障成功。
4. 在argo中编排测试流程
Argo 是一个开源的容器本地工作流引擎，用于在Kubernetes上完成工作，可以将多步骤工作流建模为一系列任务，完成测试流程编排。
我们使用argo定义一个测试任务，基本的测试流程是固定的，如下所示：
测试流程的step1是部署测试集群，接着开启两个并行任务，step2跑测试用例，模拟业务场景，step3同时使用Chaos Mesh注入故障，step2的测试用例执行结束之后，step4终止故障注入，最后step5清理集群环境。
4.1 用argo编排一个混沌测试工作流（以flashback测试用例为例）
1）修改 cluster-setup.yaml 中的image信息，改成步骤2.2 准备测试需要的镜像中自己传上去的集群部署/清理镜像名和tag
2）修改 testsuite-flashback.yaml 中的image信息，改成步骤2.2 准备测试需要的镜像中自己传上去的测试用例镜像名和tag
3）将集群部署、测试用例和工具模板的yaml文件全部使用 kubectl apply -n argo -f xxx.yaml 命令创建资源 （这些文件定义了一些argo template，方便用户写workflow时候使用）
kubectl apply -n argo -f cluster-setup.yamlkubectl apply -n argo -f testsuite-flashback.yamlkubectl apply -n argo -f tools-template.yaml
4）复制一份workflow模板文件 workflow-template.yaml，将模板文件中注释提示的部分修改为自己的设置即可，然后执行以下命令创建混沌测试工作流：
kubectl apply -n argo -f workflow-template.yaml
以下是一份workflow模板文件：
apiVersion: argoproj.io/v1alpha1kind: Workflowmetadata: generateName: chaostest-c0-0- name: chaostest-c0-0 namespace: argospec: entrypoint: test-entry #测试入口，在这里传入测试参数，填写clustername、namespace、host、greatdb镜像名和tag名等基本信息 serviceAccountName: argo arguments: parameters: - name: clustername value: c0 - name: namespace value: test - name: host value: 172.16.70.249 - name: port value: 30901 - name: password value: Bgview@2020 - name: user value: root - name: run-time value: 10m - name: greatdb-repository value: greatdb/greatdb - name: greatdb-tag value: tag202110 - name: nemesis value: kill_mysql_normal_master,kill_mysql_normal_slave,kill_mysql_partition_master,kill_mysql_partition_slave,kill_mysql_auth_master,kill_mysql_auth_slave,kill_mysql_global_master,kill_mysql_global_slave,kill_mysql_master,kill_mysql_slave,net_partition_mysql_normal,net_partition_mysql_partition,net_partition_mysql_auth,net_partition_mysql_global - name: mysql-partition value: 1 - name: mysql-global value: 1 - name: mysql-auth value: 1 - name: mysql-normal value: 2 templates: - name: test-entry steps: - - name: setup-greatdb-cluster # step.1 集群部署. 请指定正确的参数，主要是mysql和zookeeper的镜像名、tag名 templateRef: name: cluster-setup-template template: cluster-setup arguments: parameters: - name: namespace value: "{{workflow.parameters.namespace}}" - name: clustername value: "{{workflow.parameters.clustername}}" - name: mysql-image value: mysql:5.7.34 - name: mysql-replica value: 3 - name: mysql-auth value: "{{workflow.parameters.mysql-auth}}" - name: mysql-normal value: "{{workflow.parameters.mysql-normal}}" - name: mysql-partition value: "{{workflow.parameters.mysql-partition}}" - name: mysql-global value: "{{workflow.parameters.mysql-global}}" - name: enable-monitor value: false - name: zookeeper-repository value: zookeeper - name: zookeeper-tag value: 3.5.5 - name: zookeeper-replica value: 3 - name: greatdb-repository value: "{{workflow.parameters.greatdb-repository}}" - name: greatdb-tag value: "{{workflow.parameters.greatdb-tag}}" - name: greatdb-replica value: 3 - name: greatdb-serviceHost value: "{{workflow.parameters.host}}" - name: greatdb-servicePort value: "{{workflow.parameters.port}}" - - name: run-flashbacktest # step.2 运行测试用例,请替换为你要运行的测试用例template并指定正确的参数，主要是测试使用的表个数和大小 templateRef: name: flashback-test-template template: flashback arguments: parameters: - name: user value: "{{workflow.parameters.user}}" - name: password value: "{{workflow.parameters.password}}" - name: host value: "{{workflow.parameters.host}}" - name: port value: "{{workflow.parameters.port}}" - name: concurrency value: 16 - name: size value: 10000 - name: tables value: 10 - name: run-time value: "{{workflow.parameters.run-time}}" - name: single-statement value: true - name: manage-statement value: true - name: invoke-chaos-for-flashabck-test # step.3 注入故障，请指定正确的参数，这里run-time和interval分别定义了故障注入的时间和频次，因此省略掉了终止故障注入步骤 templateRef: name: chaos-rto-template template: chaos-rto arguments: parameters: - name: user value: "{{workflow.parameters.user}}" - name: host value: "{{workflow.parameters.host}}" - name: password value: "{{workflow.parameters.password}}" - name: port value: "{{workflow.parameters.port}}" - name: k8s-config value: /root/.kube/config - name: namespace value: "{{workflow.parameters.namespace}}" - name: clustername value: "{{workflow.parameters.clustername}}" - name: prometheus value: '' - name: greatdb-job value: greatdb-monitor-greatdb - name: nemesis value: "{{workflow.parameters.nemesis}}" - name: nemesis-duration value: 1m - name: nemesis-mode value: default - name: wait-time value: 5m - name: check-time value: 5m - name: nemesis-scope value: 1 - name: nemesis-log value: true - name: enable-monitor value: false - name: run-time value: "{{workflow.parameters.run-time}}" - name: interval value: 1m - name: monitor-log value: false - name: enable-rto value: false - name: rto-qps value: 0.1 - name: rto-warm value: 5m - name: rto-time value: 1m - name: log-level value: debug - - name: flashbacktest-output # 输出测试用例是否通过的结果 templateRef: name: tools-template template: output-result arguments: parameters: - name: info value: "flashback test pass, with nemesis: {{workflow.parameters.nemesis}}" - - name: clean-greatdb-cluster # step.4 清理测试集群，这里的参数和step.1的参数一致 templateRef: name: cluster-setup-template template: cluster-setup arguments: parameters: - name: namespace value: "{{workflow.parameters.namespace}}" - name: clustername value: "{{workflow.parameters.clustername}}" - name: mysql-image value: mysql:5.7 - name: mysql-replica value: 3 - name: mysql-auth value: "{{workflow.parameters.mysql-auth}}" - name: mysql-normal value: "{{workflow.parameters.mysql-normal}}" - name: mysql-partition value: "{{workflow.parameters.mysql-partition}}" - name: mysql-global value: "{{workflow.parameters.mysql-global}}" - name: enable-monitor value: false - name: zookeeper-repository value: zookeeper - name: zookeeper-tag value: 3.5.5 - name: zookeeper-replica value: 3 - name: greatdb-repository value: "{{workflow.parameters.greatdb-repository}}" - name: greatdb-tag value: "{{workflow.parameters.greatdb-tag}}" - name: greatdb-replica value: 3 - name: greatdb-serviceHost value: "{{workflow.parameters.host}}" - name: greatdb-servicePort value: "{{workflow.parameters.port}}" - name: clean value: true - - name: echo-result templateRef: name: tools-template template: echo arguments: parameters: - name: info value: "{{item}}" withItems: - "{{steps.flashbacktest-output.outputs.parameters.result}}"
Enjoy GreatSQL 🙂
