章节：如何使用Orchestrator管理MySQL主从架构

引言

在复杂的数据库环境中，维护MySQL主从复制架构的稳定性和可靠性是数据库管理员（DBA）面临的重要挑战之一。随着业务的发展，数据库架构可能会变得愈加复杂，包含多个主库、从库以及跨地域的复制环境。为了有效管理这些复杂架构，自动化工具如Orchestrator显得尤为重要。Orchestrator是一个开源的MySQL复制拓扑管理工具，它提供了自动故障转移、可视化拓扑、配置检查和修复复制错误等功能，极大地简化了MySQL主从架构的管理工作。

Orchestrator概述

Orchestrator由GitHub上的Shlomi Noach开发并维护，旨在解决MySQL复制环境中常见的故障检测、故障转移及优化问题。它通过分析MySQL的复制状态、拓扑结构以及性能指标，自动执行必要的操作来维护系统的稳定性和性能。Orchestrator支持多种MySQL复制配置，包括传统的异步复制、半同步复制以及GTID（全局事务标识符）复制等。

安装与配置Orchestrator

1. 环境准备

• MySQL环境：确保你的MySQL实例已经配置了复制，并且复制正在正常运行。
• Go语言环境：Orchestrator是用Go语言编写的，因此需要在服务器上安装Go环境。
• Git工具：用于从GitHub上克隆Orchestrator的源代码。

2. 克隆Orchestrator代码

git clone https://github.com/github/orchestrator.git
cd orchestrator

3. 编译Orchestrator

在Orchestrator的根目录下执行编译命令：

go build

这将生成一个名为orchestrator的可执行文件。

4. 配置Orchestrator

Orchestrator的配置主要通过一个YAML文件（默认为orchestrator.conf.json）进行。你需要配置MySQL实例的连接信息、Orchestrator自身的服务端口、日志级别等。

一个基本的配置示例如下：

```json
{
“RaftEnabled”: false,
“RaftDataDir”: “”,
“RaftBind”: “”,
“DefaultInstancePort”: 3306,
“MySQLTopologyUser”: “orchestrator”,
“MySQLTopologyPassword”: “password”,
“MySQLTopologySSLPrivateKeyFile”: “”,
“MySQLTopologySSLCertFile”: “”,
“MySQLTopologySSLCAFile”: “”,
“MySQLTopologySSLSkipVerify”: true,
“MySQLTopologyCredentialsConfigFile”: “”,
“MySQLTopologyUseMutualTLS”: false,
“ListenAddress”: “:3000”,
“HTTPAuthUser”: “admin”,
“HTTPAuthPassword”: “admin-password”,
“BackendDB”: “sqlite”,
“SQLite3DataFile”: “/var/lib/orchestrator/orchestrator.db”,
“ServerID”: 1000,
“StatusHostnameResolveMethod”: “none”,
“DiscoverByShowSlaveHosts”: true,
“HostnameResolveMethod”: “cname”,
“SSLPrivateKeyFile”: “”,
“SSLCertFile”: “”,
“SSLCAFile”: “”,
“SSLSkipVerify”: true,
“UseMutualTLS”: false,
“AuthUserHeader”: “”,
“HTTPAuthRealm”: “Orchestrator”,
“EnableCORS”: false,
“CORSOrigin”: “*”,
“CORSMethods”: “GET, POST, PUT, DELETE, OPTIONS”,
“CORSCredentials”: “true”,
“CORSExposedHeaders”: “Content-Length,Content-Type”,
“PowerAuthUsers”: [],
“RecoveryIgnoreHostnameFilters”: [],
“AgentPollMinutes”: 60,
“UnseenInstanceForgetHours”: 24,
“SnapshotTopologiesIntervalHours”: 0,
“InstanceBulkOperationsWaitTimeoutSeconds”: 10,
“ActiveNodeHostname”: “”,
“ClusterNameLabel”: “cluster_name”,
“ClusterAliasQuery”: “”,
“ClusterPoolInstances”: 0,
“DetectClusterAliasQuery”: “”,
“DetectClusterDomainQuery”: “”,
“DetectSemiSyncEnforcedQuery”: “”,
“DetectClusterNameQuery”: “”,
“FailMasterPromotionIfSQLThreadNotUpToDate”: true,
“DetachLostSlavesAfterMasterFailover”: true,
“PreventCrossDataCenterMasterFailover”: false,
“RecoverMasterClusterFilters”: [],
“PostponedOperationsPurgeInterval”: 0,
“ReasonableReplicationLagSeconds”: 10,
“UnreasonableReplicationLagSeconds”: 60,
“ReasonableMaintenanceReplicationLagSeconds”: 30,
“MaxTopologyInstanceLagSeconds”: 120,
“RejectHostnameResolvePattern”: “”,
“ReasonableMariaDBGaleraDelaySeconds”: 30,
“DetachSlaveMasterHost”: “”,
“PromotionIgnoreHostnameFilters”: [],
“MasterFailoverLossProbabilityThreshold”: 0,
“MasterFailoverDetachSlaveIntervalSeconds”: 3,
“SlaveStartPostMasterFailoverSeconds”: 0,
“DetectClusterAliasMaxDepth”: 10,
“RecoveryPeriodBlockSeconds”: 300,
“OnFailureDetectionProcesses”: [],
“PreFailoverProcesses”: [],
“PostFailoverProcesses”: [],
“PostUnsuccessfulFailoverProcesses”: [],
“CoProcessHostnames”: [],
“AuditLogFile”: “”,
“AuditToSyslog”: false,
“AuditKafkaBrokers”: “”,
“AuditKafkaTopic”: “”,
“AuditRetentionHours”: 0,
“DiscoveryPollSeconds”: 60,
“InstancePollSeconds”: 30,
“ContinuousDiscoveryExpiry”: 3600,
“ExpiryHostnameResolves”: 3600,
“RejectBinlogFormat”: false,
“RejectBinlogServerUuid”: false,
“ReasonableReplicationLagQuery”: “”,
“ReasonableMaintenanceReplicationLagQuery”: “”,
“EnableGTIDHa”: true,
“SkipBinlogServerUuidList”: [],
“RecoverFromAnyReplica”: false,
“MustLoginUser”: “”,
“EnableSemiSync”: false,
“EnableParticipation”: true,
“GracefulMasterTakeoverExpireTimeSeconds”: 300,
“SlaveLagQuery”: “”,
“DetectDataCenterQuery”: “”,
“UseSuperReadOnly”: true,
“UnseenInstanceForgetMinutes”: 0,
“EnableAutoMasterRecovery”: true,
“MasterRecoveryMaxFailoverAttempts”: 3,
“MasterRecoveryMaxFailoverSeconds”: 300,
“PostponeSlaveRecoveryOnLagMinutes”: 0,
“RecoverSlaveClusterFilters”: [],
“RecoverPromotionRule”: “prefer-promotable-slave”,
“CandidateInstanceExpireMinutes”: 60,
“DetachSlaveIgnoreHostnameFilters”: [],
“PromoteRule”: “least-replica-lag”,
“PreGracefulTakeoverProcesses”: [],
“PostGracefulTakeoverProcesses”: [],
“PreGracefulTakeoverProcessesWaitTimeoutSeconds”: 10,
“PreventCrossDataCenterSlaveFailover”: false,
“PreventCrossDataCenterSemiSyncMasterFailover”: false,
“RecoverSlaveLossProbabilityThreshold”: 0,
“DetachSlaveMasterHostFilter”: “”,
“RecoverIntermediateMasterClusterFilters”: [],
“CandidateInstanceExpireSeconds”: 0,
“RecoverIntermediateMasterLossProbabilityThreshold”: 0,
“DetectDataCenterOverrideQuery”: “”,
“SkipUnresolvableHostnameChecks”: false,
“FailMasterPromotionIfInstanceHasLags”: false,
“EnableUnsafeMasterFailover”: false,
“CandidateInstanceBlackholeHours”: 0,
“SlaveLagQueryOnMaster”: “”,
“PreventRemoveDataCenterMaster”: false,
“EnableLagThreshold”: false,
“SlaveStartPostIntermediateMasterFailoverSeconds”: 0,
“PreventHostnameResolvePattern”: “”,
“DetectDataCenterByInstanceLabel”: false,
“MasterRecoveryProcess”: “”,
“DetachSlaveIgnoreHostnameResolve”: false,
“EnableParticipationInRecovery”: true,
“IgnoreHostnameFilters”: [],
“CandidateInstanceMaxLagSeconds”: 0,
“DetectSemiSyncMaster”: false,
“DetectDataCenterByHostnamePattern”: “”,
“DetectClusterDomainByHostnamePattern”: “”,
“CandidateInstanceMaxBinlogSecondsBehindMaster”: 0,
“CandidateInstanceMinReplicaCount”: 0,
“RecoverIntermediateMasterIgnoreHostnameFilters”: [],
“PreventHostRemove”: false,
“SlaveStartPostMasterFailoverIgnoreHostnameFilters”: [],
“RecoverSlaveIgnoreHostnameFilters”: [],
“PreventRemoveCandidateInstance”: false,
“SlaveStartPostIntermediateMasterFailoverIgnoreHostnameFilters”: [],
“CandidateInstanceIgnoreHostnameFilters”: [],
“EnableParticipationInIntermediateMasterRecovery”: true,
“PreventHostRemoveDataCenter”: false,
“DetachSlaveIgnoreDataCenter”: false,
“RecoverSlaveDetachSlaveIntervalSeconds”: 3,
“DetachSlaveIgnoreDataCenterMasterHost”: false