How to view read-only instances in TencentDB for SQL Server?
1. Log in to the SQL Server Console. In the instance list, instances with an "R" Tag are read-only instances. You can click on the instance ID or the Operation column's Manage to enter the details page and view the read-only instance details.
2. In the master instance details page, you can access the details page of the read-only instance through the topology diagram of the master instance.
Note:
Some features of the read-only instance details page are restricted from modification, synchronized with the configuration of its master instance. If changes are needed, please make them on the master instance's details page. For more details, see Managing Read-Only Instances.
Does TencentDB for SQL Server support read-write separation?
Currently, TencentDB for SQL Server does not support a unified read-write separation address, meaning it does not automatically separate read requests from write requests. Read-only instances need to be accessed through a separate IP and PORT. After creating a read-only instance, you need to configure the connection addresses for both the master instance and each read-only instance in your application to direct write requests to the master instance and read requests to the read-only instances. For more details, see Overview of Read-Only Instances.
How to create a read-only instance in TencentDB for SQL Server?
1. Log in to the SQL Server Console. In the instance list, click on the instance ID or the Operation column's Manage to enter the details page.
2. In the instance details page, click on Add Read-Only Instance in the instance architecture diagram, or select the Read-Only Instance page, click Create to enter the purchase page. For more details, see Managing Read-Only Instances.
How to create a RO Group for read-only instances in TencentDB for SQL Server?
TencentDB for SQL Server allows users to create one or more read-only instances to form a Read-Only Instance (RO) group, suitable for read-write separation and one-to-many application scenarios. It can significantly improve the read load capacity of the user's database. For more details, see Read-Only Instance RO Group.
What is the synchronization delay from the master to the read-only instance in TencentDB for SQL Server?
For versions below 2017, replication synchronization has a delay of 3 to 5 seconds. For 2017/2019 versions using Always On replicas for read-only, the synchronization delay is 1 to 2 seconds.
Do different versions of read-only instances have any differences? If the business needs to use read-only, how should I choose the version of TencentDB for SQL Server?
Different versions of read-only instances do have differences. If your business requires read-only functionality, it is recommended to use the 2017 version or later database instances for the following reasons:
Versions below 2017 use the publish-subscribe method to construct read-only instances, which is object-level synchronization. The synchronization delay is 3 to 5 seconds. If you use read-only instances, to ensure efficient and stable data synchronization, it is recommended to upgrade the primary instance to version 2017 or later before using the read-only instance feature.
The 2017 Enterprise Dual Node (original High Availability Version/Cluster Version) and above versions use the Always-On method to construct read-only instances, with a synchronization delay of 1 to 2 seconds. Data synchronization is more efficient and stable.
Can I use accounts created in the primary instance in read-only instances?
Accounts created in the primary instance will be synced to read-only instances, but read-only instances cannot manage accounts. Accounts in read-only instances can only perform read operations, not write operations.
How many read-only instances can be created per primary instance in TencentDB for SQL Server?
A primary instance in TencentDB for SQL Server can create a maximum of 5 read-only instances. If you need to create more, please submit a ticket for a solution.
Does TencentDB for SQL Server support data migration to read-only instances?
TencentDB for SQL Server does not support data migration to read-only instances.
Do read-only instances in TencentDB for SQL Server support creating/deleting databases?
Read-only instances in TencentDB for SQL Server do not support creating or deleting databases. If needed, please operate on the primary instance.
Do read-only instances in TencentDB for SQL Server support creating/deleting accounts?
Read-only instances in TencentDB for SQL Server do not support creating or deleting accounts, nor do they support account authorization or changing account names and passwords. If needed, please operate on the primary instance.
Do read-only instances in TencentDB for SQL Server support backup and rollback?
Read-only instances in TencentDB for SQL Server do not support backup and rollback. If needed, please operate on the primary instance.
Do I need to re-enable load balancing after defining weight in TencentDB for SQL Server?
If rebalancing is disabled, modifying weight will only affect new loads and will not impact read-only instances accessed by existing persistent connections, thus not causing momentary database disconnections. When rebalancing is enabled, the database will experience momentary disconnections to break all connections, and new connections will be load-balanced according to the set weights. Users can choose whether to re-enable load balancing based on their needs.