Cost-effectiveness |
- Scalable resources are provided.
- SQL Server Web Edition is supported to increase cost-effectiveness.
- A free quota for backup storage is provided. The free quota is equal to half the purchased
storage capacity. For more information, see Backup storage fees of an ApsaraDB RDS for SQL Server instance.
- Internet traffic is free of charge.
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- Scalable resources are provided.
- SQL Server Web Edition is not supported.
- You are charged for the backup storage that you use.
- You are charged for the Internet traffic that you consume.
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- The initial investment cost is high.
- SQL Server Web Edition is not supported.
- You must allocate independent backup resources. This requires high costs.
- You are charged for the Internet traffic that you consume and the domain names that
you use. The domain names are charged at high prices.
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Availability |
- In RDS Basic Edition, your database system requires approximately 15 minutes to complete
a failover.
- In RDS High-availability Edition or RDS Cluster Edition, your database system runs
in a proprietary high-availability architecture of Alibaba Cloud. This architecture
allows your database system to complete a failover within 30 seconds.
- In RDS Cluster Edition, you can create read-only RDS instances to balance loads in
your database system. For more information, see Overview of read-only ApsaraDB RDS for SQL Server instances.
- In RDS Cluster Edition, you can use read/write splitting to distribute read and write
requests by using a unified read/write splitting endpoint. For more information, see
Overview of read/write splitting.
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- In the basic edition, your databases require approximately 30 minutes to complete
a failover.
- You must purchase additional software or hardware to build a high-availability architecture.
- You must configure or purchase additional software or hardware to build a load balancing
architecture.
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- Your databases are standalone. If a database server breaks down, repairs can take
hours to weeks.
- You must purchase additional software or hardware to build a high-availability architecture.
- You must configure or purchase additional software or hardware to build a load balancing
architecture.
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Reliability |
- Automated replication of data between primary and secondary RDS instances, data backups,
and log backups are supported to ensure high data reliability.
- RDS Cluster Edition delivers an RPO of 0.
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- Your databases are highly available only when they are deployed in an optimal high-availability
architecture.
- To ensure an RPO of 0, you must purchase independent R&D services. This requires high
costs.
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- Data reliability is moderate and varies based on the corruption probability of individual
disks.
- To ensure an RPO of 0, you must purchase independent R&D services. This requires high
costs.
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Usability |
- An automated backup and restoration system is provided to support PITR and database-level
backup and restoration. In addition, streaming backups are supported to minimize the
impacts on performance. For more information, see Back up an ApsaraDB RDS for SQL Server instance.
- An automated monitoring and alerting system allows you to monitor all supported metrics
at the instance and database levels and view monitoring information that is collected
over a time range of a few seconds. If the value of a metric exceeds the specified
threshold, ApsaraDB RDS sends you an alert by using SMS, email, or DingTalk. In addition,
a free quota for alert notifications over SMS is provided based on your purchase details.
For more information, see Configure an alert rule for an ApsaraDB RDS for SQL Server instance.
- Geo-disaster recovery is in development.
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- Automated backups are not supported. You must purchase or configure the streaming
backup and PITR features. This requires high costs.
- You must purchase an independent monitoring system and configure it in the CloudMonitor
console.
- Technical challenges are imposed on usability.
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- Automated backups are not supported. You must purchase or configure the streaming
backup and PITR features. This requires high costs.
- You must purchase or configure an independent monitoring system. This requires high
costs.
- Remote data centers require high costs and are difficult to be built. As a result,
geo-disaster recovery is difficult to be implemented.
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Performance |
- RDS instances that run SQL Server 2008 R2 with local SSDs provide high performance.
RDS instances that run SQL Server 201x support next-generation compute-storage separation
and can benefit from hardware dividends.
- RDS instances that are equipped with ESSDs provide higher performance than RDS instances
that are equipped with local SSDs or standard SSDs.
- You can create read-only RDS instances to improve performance and balance loads.
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- If you choose local disks, data reliability is reduced. If you choose cloud disks,
you must plan a disk architecture. This requires high costs.
- ECS-hosted self-managed databases that are equipped with ESSDs are inferior to RDS
instances that are equipped with ESSDs in terms of performance.
- The cluster edition is difficult to be deployed and requires high consultancy costs
and high maintenance costs.
- You must recruit experienced DBAs. This requires high costs.
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- Database servers are updated at lower speeds than cloud computing hardware. Therefore,
self-managed databases on these servers are inferior to RDS instances.
- Computing-storage separation is difficult to be implemented and can require you to
spend millions of US dollars on advanced storage media.
- The cluster edition is difficult to be deployed and requires high consultancy costs
and high maintenance costs.
- You must recruit experienced DBAs. This requires high costs.
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Security |
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- IP address whitelists, security groups, and VPCs can be used to control access to
ECS-hosted self-managed databases.
- Link encryption and disk encryption must be separately configured to protect data.
This requires high consultancy costs.
- SQL logs are difficult to be audited because they must be separately stored.
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- IP address whitelists and VPCs can be used to control access to self-managed databases
on third-party servers. This requires high consultancy costs.
- Link encryption and disk encryption must be separately configured to protect data.
This requires high consultancy costs.
- SQL logs are difficult to be audited because they must be separately stored.
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Legal liability |
ApsaraDB RDS for SQL Server is provided with a valid license. No legal liabilities
are imposed on you.
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You must purchase a valid license. |
You must purchase a valid license. Otherwise, legal liabilities may be imposed on
you.
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