aws 数据库迁移
When migrating your SQL databases to the cloud you need to make your choice carefully. Migration is time-consuming and can be costly, in terms of resources, support, and downtime. You don’t want to lose productivity or revenue when migrating to a service, only to find there was a better option available.
将SQL数据库迁移到云时，您需要仔细选择。 就资源，支持和停机时间而言，迁移既耗时又成本高昂。 您不想在迁移到服务时就失去生产力或收入，只是发现有一个更好的选择。
In this article, you’ll learn how AWS services compare to Azure and why migrating your databases to Azure can provide greater returns. In particular, you’ll learn how Azure’s migration solutions, flexible deployments, and licensing support can provide better value for organizations seeking an enterprise-grade solution.
在本文中，您将了解AWS服务与Azure的比较以及为什么将数据库迁移到Azure可以提供更大的回报。 特别是，您将学习Azure的迁移解决方案，灵活的部署和许可支持如何为寻求企业级解决方案的组织提供更好的价值。
When migrating to AWS, you can replatform your database to Amazon Relational Database Service (RDS). RDS is a managed service that supports several database engines, including, Amazon Aurora, PostgreSQL, Oracle, MariaDB, MySQL, and Microsoft SQL Server. It takes care of infrastructure maintenance for you in exchange for flexibility and granular control.
迁移到AWS时，您可以将数据库重新平台化为Amazon Relational Database Service(RDS)。 RDS是一项托管服务，支持多个数据库引擎，包括Amazon Aurora，PostgreSQL，Oracle，MariaDB，MySQL和Microsoft SQL Server。 它为您照顾了基础架构维护，以换取灵活性和精细控制。
Within RDS, there are two architecture types. With all engines except Aurora, your database is hosted on a storage volume and the engine is hosted on a compute instance (similar to EC2 and EBS). This enables you to provision storage and compute resources independently. However, to scale, your only option is to create read replicas and you cannot scale automatically.
在RDS中，有两种体系结构类型。 对于除Aurora之外的所有引擎，您的数据库都托管在一个存储卷上，而该引擎则托管在一个计算实例上(类似于EC2和EBS)。 这使您可以独立配置存储和计算资源。 但是，要进行缩放，唯一的选择是创建只读副本，并且无法自动缩放。
Aurora is a proprietary database created by AWS and is compatible with MySQL and PostgreSQL databases. In Aurora, storage scales with compute resources, eliminating the need to provision resources separately. This option allows you to scale up to 15 read-replicas.
Aurora是由AWS创建的专有数据库，并且与MySQL和PostgreSQL数据库兼容。 在Aurora中，存储可随计算资源扩展，从而无需单独配置资源。 此选项允许您最多扩展15个只读副本。
AWS Database Migration Service (DMS)
AWS数据库迁移服务(DMS)
To make migration easier, Amazon offers AWS DMS. This service enables you to perform online, homogeneous (i.e. SQL Server to SQL Server) or heterogeneous (i.e. SQL Server to PostgreSQL) migrations.
为了简化迁移，Amazon提供了AWS DMS 。 此服务使您可以执行联机，同质(即，从SQL Server到SQL Server)或异构(即，从SQL Server到PostgreSQL)迁移。
With DMS, you can transfer a static copy of your database or a database with logged changes. You can also use the service to supplement a manual migration by only replicating changes that occur after your database copy is made.
使用DMS，您可以传输数据库的静态副本或具有记录的更改的数据库。 您还可以使用该服务来补充手动迁移，方法是仅复制数据库副本制作后发生的更改。
To use this service, you select your compute instance type and provision storage for logs and change caching. Once your resources are defined you can specify the type of migration you want (full copy, fully copy with changes, or changes only) via the creation of a replication task which specifies your database endpoints, credentials, etc.
要使用此服务，请选择您的计算实例类型并为日志和更改缓存配置存储。 定义资源后，您可以通过创建复制任务来指定所需的迁移类型(完整副本，带有更改的完整副本或仅更改)，该任务指定数据库端点，凭据等。
Unfortunately, this service does not support automatic migrations. It also does not support the conversion of schema if you are doing a heterogeneous migration.
不幸的是，此服务不支持自动迁移。 如果您要进行异构迁移，它也不支持架构转换。
When migrating to Azure, you can transfer your data to Azure SQL Database. It is a managed Platform as a Service (PaaS) that supports SQL Server workloads. With this service you are responsible for managing your data, access, and any applications. However, Microsoft takes care of the infrastructure and database engine maintenance.
迁移到Azure时，可以将数据传输到Azure SQL数据库。 它是支持SQL Server工作负载的托管平台即服务(PaaS)。 使用此服务，您有责任管理您的数据，访问和任何应用程序。 但是，Microsoft负责基础结构和数据库引擎维护。
When using SQL Database, you have three deployment options — Managed Instance, Single, or Elastic Pool. Managed Instances are clusters of databases sharing an engine and Elastic Pool is a collection of single databases with shared resources.
使用SQL数据库时，您有三个部署选项-受管实例，单个或弹性池。 受管实例是共享引擎的数据库集群，而Elastic Pool是具有共享资源的单个数据库的集合。
Single is a single, isolated database. With Single, you can customize your provisioning by specifying resource amounts, specifying performance, or using serverless to scale automatically. The other two options dynamically scale.
单个是一个隔离的数据库。 使用Single，您可以通过指定资源数量，指定性能或使用无服务器自动缩放来自定义配置。 其他两个选项可动态扩展。
When using SQL Database you have the ability to create hybrid databases. You can create a fully hybrid system with a replica in the cloud through Azure SQL Data Sync, which continuously syncs data. You can also create a partial hybrid through the addition of Stretch Database, which is a service that transparently migrates cold data from on-premises servers to the cloud.
使用SQL数据库时，您可以创建混合数据库。 您可以通过Azure SQL Data Sync创建一个具有副本的完全混合系统，该副本将在云中持续同步数据。 您还可以通过添加Stretch Database创建部分混合服务器，Stretch Database是一项服务，可以将冷数据从本地服务器透明地迁移到云中。
Azure Database Migration Service
Azure数据库迁移服务
To assist with migrating your data, Microsoft provides the Azure Database Migration Service. This service supports SQL Server, PostgreSQL, MySQL, and MongoDB migrations and you can use it to transfer your data to SQL Database, Database for PostgreSQL, MySQL, and Cosmos DB.
为了协助您迁移数据，Microsoft提供了Azure数据库迁移服务。 此服务支持SQL Server，PostgreSQL，MySQL和MongoDB迁移，您可以使用它将数据传输到SQL数据库，PostgreSQL数据库，MySQL和Cosmos DB。
Database Migration Service supports homogeneous and heterogeneous migrations, both on and offline, with change replication. It can also move data, schema, and objects. It is resilient and self-healing, enabling it to automatically resume following an interruption with no data loss or corruption. Additionally, unlike AWS DMS, this service allows automation via PowerShell commandlets.
数据库迁移服务通过更改复制支持在线和离线的同构和异构迁移。 它还可以移动数据，架构和对象。 它具有弹性和自我修复功能，使其能够在中断后自动恢复，而不会丢失数据或损坏数据。 此外，与AWS DMS不同，此服务允许通过PowerShell Commandlet进行自动化。
Included in the service is a Data Migration Assistant (DMA) that provides reports of your migration progress and can provide optimization suggestions. It enables you to assess the readiness of your on-premises database before migration, identify issues and opportunities for improvement, and manage your migration for you.
该服务中包括一个数据迁移助手( DMA )，它提供有关迁移进度的报告并可以提供优化建议。 它使您能够在迁移之前评估本地数据库的准备情况，确定问题和改进机会，并为您管理迁移。
Choosing the right managed SQL database can be challenging; both AWS and Azure are valid options and can meet your needs. However, there are few areas in which Azure excels, namely enterprise-grade migration tooling, significant flexibility in deployment, and easy integration with existing Microsoft products.
选择正确的托管SQL数据库可能具有挑战性。 AWS和Azure都是有效的选项，可以满足您的需求。 但是，Azure擅长的领域很少，即企业级迁移工具，极大的部署灵活性以及与现有Microsoft产品的轻松集成。
Migration tooling
迁移工具
Azure automated migration capabilities you won’t find in AWS. For large migrations, automation means significant time savings. It also means greater reliability since it leaves less room for user error.
在AWS中找不到的Azure自动迁移功能。 对于大型迁移，自动化意味着可节省大量时间。 这也意味着更高的可靠性，因为它为用户提供了更少的错误空间。
Another advantage of Azure migration tools is the inclusion of DMA. While AWS tooling can perform your migration processes with similar results to Azure tools, it cannot help you prepare for, plan, or improve your migrations. DMA, however, can provide feedback to ensure that your databases are transferred smoothly and reliably. Otherwise, with AWS, you would have to seek professional services or in-house expertise to get similar evaluation and guidance.
Azure迁移工具的另一个优点是包含DMA。 尽管AWS工具可以执行与Azure工具相似的迁移过程，但它无法帮助您准备，计划或改善迁移。 但是，DMA可以提供反馈，以确保您的数据库顺利，可靠地传输。 否则，使用AWS，您将必须寻求专业服务或内部专业知识才能获得类似的评估和指导。
Deployment options
部署选项
Azure supports the widest range of deployment options. AWS does not provide as many configurations for databases as Azure, or support hybrid deployments with the same ease. Additionally, migrating databases to AWS can lock you into AWS services for the remaining life of your database.
Azure支持最广泛的部署选项。 AWS不提供像Azure那样多的数据库配置，或者同样轻松地支持混合部署。 此外，将数据库迁移到AWS可以在数据库的剩余生命周期内将您锁定在AWS服务中。
Meanwhile, migrating to Azure can provide you with the security of flexibility. When you choose Azure your data can be migrated back on-premises or back to a SQL Server instance in the cloud of your choice with minimal issues.
同时，迁移到Azure可以为您提供灵活性的安全性。 选择Azure时，可以以最少的问题将数据迁移回本地或迁移到所选云中SQL Server实例。
Licensing and Microsoft integrations
许可和Microsoft集成
AWS RDS only supports license-included deployments. Even if you already have Microsoft licenses, you’ll be forced to repurchase licenses through service fees. With Azure, you can either include licenses in fees or to bring your existing licenses, reducing technical debt.
AWS RDS仅支持包含许可证的部署。 即使您已经拥有Microsoft许可证，也将被迫通过服务费重新购买许可证。 使用Azure，您可以将许可证包括在费用中，也可以携带现有许可证以减少技术债务。
Another benefit of Azure is built-in integration with existing Microsoft tools, such as Active Directory or Office 365. You can use these tools with AWS, but you will not get the same support or ease of integration that you get with Azure. If your organization relies on Microsoft products, ease of integration, and assured support, then you might want to opt for Azure.
Azure的另一个好处是与现有Microsoft工具(例如Active Directory或Office 365)的内置集成。您可以将这些工具与AWS一起使用，但无法获得与Azure相同的支持或易于集成。 如果您的组织依靠Microsoft产品，易于集成和有保证的支持，则您可能希望选择Azure。
AWS is a great choice for smaller migrations or organizations that are already running significant workloads in the AWS cloud. However, for larger enterprise migrations, Azure is the clear winner. Microsoft provides much more powerful options for planning and automating your migration, and provides far more granular deployment options to let you customize resource utilization and scalability. Even without the large discounts provided by the Hybrid Benefits program, Azure is a great option. If you’re moving SQL Server, selecting Azure is a no-brainer.
对于较小的迁移或已经在AWS云中运行大量工作负载的组织，AWS是一个不错的选择。 但是，对于大型企业迁移，Azure无疑是赢家。 Microsoft提供了更强大的计划和自动化迁移选项，并提供了更精细的部署选项，可让您自定义资源利用率和可伸缩性。 即使没有Hybrid Benefits计划提供的大量折扣，Azure还是一个不错的选择。 如果要移动SQL Server，那么选择Azure无疑是明智之举。
翻译自: https://medium.com/@eddies_47682/migrating-your-sql-database-to-the-cloud-aws-vs-azure-d788aa342fd
aws 数据库迁移
