How do I select an appropriate architecture of TencentDB for SQL Server?
TencentDB for SQL Server architecture supports single-node (originally Basic Edition) and dual-node (originally High-availability/Cluster Edition) setups. To ensure high availability of instances, we recommend opting for the dual-node architecture (originally High-availability/Cluster Edition) and deploying across AZ for high availability<1>. If your application has a strong dependency on SA permissions, a single-node (originally Basic Edition) may be selected. The differences between architectural versions are as follows:
Two-node (formerly high-availability/cluster edition):
SQLServer 2008 R2, 2012, 2014, 2016 Enterprise/Standard versions use Database Mirroring for high-availability replication, providing second-level automatic switching and "zero" data loss reliability.
SQL Server 2017, 2019 Enterprise/Standard, 2022 Enterprise: They adopt AlwaysOn technology to build a high-performance, high-availability, high-reliability, and easy-maintenance SQL Server cluster.
Single-node (formerly basic edition): It is deployed on a single node with storage/computing separation, uses premium cloud disks for three-copy storage to avoid data losses, and fully opens up its SA permissions.
How do I select the architecture and version of TencentDB for SQL Server if a read-only feature is required?
If read-only access is needed, it is recommended to use SQL Server 2017 Enterprise, SQL Server 2019 Enterprise, or SQL Server 2022 Enterprise editions with the dual-node architecture (originally High-availability/Cluster Edition) for more efficient and stable data synchronization. For details, see Read-only Instance Overview and Read-only Instance Specifications.
How is the performance of TencentDB for SQL Server?
TencentDB for SQL Server provides the single-node architecture (formerly basic edition) and primary/replica two-node architecture (formerly high-availability/cluster edition):
The highest TPM of the single-node architecture (formerly basic edition - premium cloud disk) is 1.32 million.
The highest TPM of the single-node architecture (formerly basic edition - SSD) is 1.38 million.
The highest TPM of the primary/replica two-node architecture (formerly high-availability/cluster edition) is 4.58 million.
Which specifications does TencentDB for SQL Server support?
For specifications of TencentDB for SQL Server single-node (originally Basic Edition) and dual-node (originally High-availability/Cluster Edition) master instances, see Master Instance Specification List. For read-only instance specifications, see Read-only Instance Specification List.
How do I select an appropriate TencentDB for SQL Server instance specification?
TencentDB for SQL Server specifications can be chosen based on capacity and performance. Capacity is determined by data storage needs. For supported instance specifications, see Master Instance Specification List and Read-only Instance Specification List. For performance, refer to Performance Test Report.
In which regions is TencentDB for SQL Server available?
What versions does TencentDB for SQL Server support?
How is the compatibility of TencentDB for SQL Server?
TencentDB for SQL Server is backward compatible. For example, you can upgrade or migrate TencentDB for SQL Server 2016 to 2019 but cannot downgrade or migrate TencentDB for SQL Server 2019 to 2016.
What features does TencentDB for SQL Server offer?
Features supported by different series versions of TencentDB for SQL Server may vary. For details, see Feature Overview and Differences and Constraints and Limitations.
What are the differences in the features supported by different versions of TencentDB for SQL Server?
For features supported by different versions of TencentDB for SQL Server and their differences, please see Feature Overview and Differences.
How many databases can I create at most in a TencentDB for SQL Server instance?
From a performance perspective, having too many databases in TencentDB for SQL Server can lead to a decline in instance performance, occupy Worker Thread resources, and exceed the limit for the number of databases, potentially causing primary-secondary synchronization anomalies. It is recommended not to exceed the maximum limit of databases per instance. The number of databases an instance can support is related to the instance CPU cores. For detailed formulas on the maximum number of databases per version, refer to Database Quantity.
You can also use SSMS to connect to the instance and create databases, and databases created via SSMS will be automatically synced to the replica instance. However, to avoid exceptions during primary-replica sync, we recommend that you not create more databases than the specified limit.
Does TencentDB for SQL Server support real-time hot backup?
TencentDB for SQL Server two-node (formerly high-availability/cluster edition) instances support real-time hot backup in a one-primary-one-replica architecture.
What are the use cases of TencentDB for SQL Server?
TencentDB for SQL Server is suitable for various application scenarios including industry tools, mobile offices, gaming, medical, pharmaceuticals, media, Internet, IoT, retail, e-commerce, logistics, insurance, securities, technical services, automotive, travel, finance, and more. For details, see Application Scenarios.
What high availability and disaster recovery capabilities does TencentDB for SQL Server have?
TencentDB for SQL Server provides disaster recovery capabilities at different levels, including instance, server, data center, AZ, and region, to ensure the business continuity on healthy systems with the minimum data loss in case of natural disasters, device failures, and maloperations.
Backup is the basis of all disaster recovery systems and the last line of defense in the high data availability architecture. TencentDB for SQL Server features rich backup capabilities, ensuring that the data can be restored quickly even after a total system crash to guarantee the business continuity as much as possible.
TencentDB for SQL Server provides instances in various architectures with guaranteed high availability:
A SQL Server 2008R2/2012/2014/2016 Enterprise two-node (formerly high-availability/cluster edition) instance is in the primary/replica two-node architecture, where the underlying layer is deployed on a physical machine. It supports the database mirroring (high-availability replication) scheme to implement automatic HA switch within seconds.
In two-node (formerly high-availability/cluster edition) instances, SQL Server 2017/2019/2022 Enterprise versions feature primary/replica nodes deployed on physical machines. They use AlwaysOn technology to build a high-performance, high-availability, high-reliability, and easy-maintenance SQL Server cluster, offering HA automatic switch in seconds.
A single-node (formerly basic edition) instance is in the single-node architecture, where the underlying layer is deployed in a CVM instance, storage and computing are separated, and data is stored in three copies in premium cloud disk to avoid data loss. In extreme cases where an instance fails, a new instance will be started to automatically restore the data from data and log backups. The specific restoration time is subject to the data volume. The servers of two TencentDB instances are usually on the same physical machine.
For intra-region disaster recovery, TencentDB for SQL Server provides multi-AZ deployment capabilities. Different AZs in the same region are interconnected over the private network, and failures can be isolated between AZs. For instances in the primary/replica two-node architecture, the primary and replica instances can be deployed in different AZs in the same region (for example, one primary instance in the primary AZ and one replica instance in the replica AZ). This improves the business continuity and guarantees the data availability in case of instance failures or AZ disconnections. You can also manually switch between the primary and replica instances in the console to verify the business robustness. Switches within the same AZ and between different AZs are imperceptible to the application.
For remote disaster recovery, cross-region backup capabilities are offered to store backup files in another region. You can set the cross-region backup retention period and multiple backup regions. After a cross-region backup policy is enabled, the instance backup files will be automatically stored in the target region. In this way, if an instance in a region fails, you can restore its backup files in the remote region to a new instance there for guaranteed business continuity. Cross-region backup implements the high availability of database restoration and meets the requirements for data availability and security, remote backup and restoration, remote disaster recovery, long-term data archive, and regulation compliance.
In addition, TencentDB for SQL Server also has rich backup capabilities to guarantee the data security and prevent data loss or corruption. Specifically, you can configure automatic backup, manual backup, data backup, log backup, backup file format (unarchived files or archive file), instance backup, and multi-database backup. You can also customize the backup policy, backup retention period (7–1,830 days), and backup cycle.
Moreover, TencentDB for SQL Server comes with comprehensive disaster recovery capabilities at both the data and business management layers. Cross-region disaster recovery for databases is meaningful only if the business also features cross-region disaster recovery. However, cross-region distributed deployment of the business inevitably causes the split-brain problem. At the business management layer, the business is deployed in three AZs (two intra-region AZs and one remote AZ) to ensure the business continuity. Before an actual failover occurs, the system will always check whether the database sync status (database sync system table) is normal to avoid faulty failover.
What strengths does TencentDB for SQL Server have?
TencentDB for SQL Server is licensed by Microsoft to continuously provide you with the latest features, so you can avoid any risks arising from unauthorized software use. It features out-of-the-box usage, high stability, reliability, and security, elastic scaling, data security protection, and failover in seconds, allowing you to focus on application development.
Diverse editions: Two deployment architectures are available, namely, single-node architecture (formerly basic edition) and two-node architecture (formerly high-availability/cluster edition), to comprehensive guarantee the high service availability.
Official license: Licensed by Microsoft, TencentDB for SQL Server continuously provides you with the latest features, helping you avoid the risks of using unauthorized software and enhance the trustworthiness of your business in competitive markets.
Excellent performance: The new ultra-high specification of 90-core 720 GB MEM is released, with a TPM of up to 4.5 million. Both performance and cost performance have been improved by more than 30% once again, breaking Tencent Cloud's own performance record in the industry.
High stability and reliability: TencentDB for SQL Server delivers a 99.9996% data reliability and 99.95% service availability. It provides easy-to-use cloud-based control capabilities, such as monitoring and alarming, backup and restoration, data migration, and elastic scaling.
Ease of management: Various management tasks can be finished with ease in the Tencent Cloud console or SSMS, such as database management, permission configuration, and monitoring and alarming. This eliminates your concerns over database installation and Ops.
Monitoring and alarming: Dozens of key metrics can be viewed in the console, such as the number of connections and requests, disk I/O, and buffer hit rate, helping you comprehensively monitor database conditions and accurately understand the database load and system health. User-defined resource threshold alarms are supported to help you discover database exceptions timely and resolve potential system problems quickly.
BI: SSIS + BI analysis services are provided, which integrate data storage, ETL, and visual analysis to help meet your diversified needs in various use cases, including BI analysis, high-value data mining, and primary data management system setup.
What strengths does TencentDB for SQL Server have over self-built SQL Server?
TencentDB for SQL Server has the following strengths over self-built databases:
Feature | TencentDB for SQL Server | Self-Built SQL Server |
Service availability | You have to guarantee the service availability and set up primary/replica replication and RAID capabilities on your own. | |
System security | Anti-DDoS is supported, and various database security vulnerabilities are fixed in time. The data security meets all mainstream national and international security standards. | You have to deploy security services and fix vulnerabilities on your own at high costs. Security compliance is not guaranteed, and the security requirements cannot be quickly met. |
Database performance | High-performance devices, excellent performance, TPM of up to 4.5 million. For more information, see Performance Test Report. | General devices without optimization and fine-tuning are used. |
Software and hardware investment | No hardware or software investment is required, and the service is pay-as-you-go. | Database servers are costly. |
System hosting | There are no hosting fees. | The hosting fees are high. |
Deployment and scaling | The out-of-the-box service can be quickly deployed and elastically scaled. | You have to purchase hardware devices, host them in data centers, and deploy them on your own. You also have to solve stability problems and set up many supporting modules and management tools, which require heavy investments in technology and take a long period of time. |
Resource utilization | The service is billed by the actual usage and supports elastic scaling to ensure a high resource utilization. | You have to consider traffic spikes, and the resource utilization is low. |
Data disaster recovery | Primary/replica replication and backup are configured by default. Both intra-region and cross-region disaster recovery schemes are supported, such as multi-AZ deployment and cross-region backup. | You have to find the backup storage space and regularly verify whether backups can be restored, which cost more money and time. |
Control and management services | Comprehensive cloud-based instance lifecycle management capabilities are available for various objects, including monitoring and alarming, backup and restoration, instance, database, account, network, parameter, and log. | All control capabilities require user construction. |
Procurement costs | Instances are priced transparently and even more cost-effective than CVM. | In addition to instances, you also have to set up disaster recovery, monitoring, and management systems on your own at totally uncontrollable costs. |
License | Official licenses from Microsoft continuously provide you with the latest features, eliminating your need to purchase additional licenses. | Pirated services lead to legal risks, while official licenses are expensive. |
Ops costs | No need for user maintenance. Tencent Cloud provides quality service with a 24/7 professional team for large customers. | You have to hire dedicated DBAs for database maintenance, which incurs high labor costs. |
How do I migrate data to TencentDB for SQL Server?
TencentDB for SQL Server supports self-built databases in local IDCs, self-built databases on Tencent Cloud CVM servers, self-built databases on other cloud vendors' CVM, other cloud vendors' cloud databases, and migration of Tencent Cloud databases to TencentDB for SQL Server. It supports Cold Backup Migration and Migration with DTS. You can choose the appropriate migration method based on your business scenario.
If your business allows you to shut down the database for backup, you can use Cold Backup Migration, i.e., restoring data from .bak backup files to migrate the source database to TencentDB for SQL Server. You can download COS files or upload local files for migration. Three data restoration modes are supported: full backups, full backups + log backups, and full backups + differential backups.
If your business doesn't allow you to shut down the database and requires smooth migration, you can Migrate with DTS. DTS supports two migration modes: full migration and full + incremental migration. It supports multiple access types, such as public network, self-built cloud hosts, Direct Connect, VPN access, CCN access, and cloud databases.