This document describes how to set the database proxy connection address in the TencentDB for MySQL console.
The database proxy connection address is independent of the original database connection address. Requests proxied at the proxy address are all relayed through the proxy cluster to the source and replica nodes of the database, so that read and write requests are separated, with reads being forwarded to read-only instances. In this way, the load of the source database is lowered.
After database proxy is enabled for TencentDB for MySQL, a database proxy connection address will be added by default, and you can also add, modify, or delete the connection address for database proxy.
1. Log in to the TencentDB for MySQL console. In the instance list, click an Instance ID or Manage in the Operation column of the instance with the proxy enabled to enter the instance management page.
2. On the instance management page, select the Database Proxy tab and click the
icon next to Private Network Access Address on the Connection Address tab.
3. In the pop-up dialog box, modify the proxy address and click OK.
Note:
Modifying the proxy address affects the database business being accessed. We recommend you modify the address during off-peak hours. Make sure that your business has a reconnection mechanism.
Adding Database Proxy Connection Address
Note:
The maximum number of database proxy connection addresses is 7.
A connection address will be created by default when the database proxy is enabled.
1. Log in to the TencentDB for MySQL console. In the instance list, click an Instance ID or Manage in the Operation column of the instance with the proxy enabled to enter the instance management page.
2. On the instance management page, select the Database Proxy tab, and click Add Access Address next to Connection Address.
3. In the Create Connection window, set the following configuration items and click OK.
Step 1. Configure a network
Parameter
Description
Network Selection
Database proxy only supports VPC. You can choose to automatically assign or specify an address.
Security group
The security group of the source instance is selected by default. You can also select another or more existing security groups or create a new one as needed.
Note：
To access through the database proxy, you need to configure security group policies and open the private port (3306). For more information, see TencentDB Security Group Management.
Remarks
Optional. You can add remarks for the new database proxy connection address.
Step 2: Configure a policy
Note：
Network forwarding is only supported for instances with TencentDB for MySQL Cluster Edition (cloud disk) architectures. If network forwarding is enabled during configuration, the following capabilities are not supported: adaptive load balancing, connection pool, and transaction split.
Parameter
Description
Read/Write Attribute
Select the read-write attribute of the proxy access address, which can be Read/Write Separation or Read-Only.
Network Forwarding
You can set whether to enable network forwarding. This option is supported only for instances with TencentDB for MySQL Cluster Edition (cloud disk) architectures. Once enabled, SQL distribution will be performed through network forwarding.
Remove Delayed RO Instances
Set the Remove Delayed RO Instances policy. After this option is enabled, you can set Delay Threshold and Least RO Instances. The system will try removing or restoring a failed read-only instance no matter whether this option is enabled.
Delay Threshold: Enter an integer greater than or equal to 1 (in seconds).
Least RO Instances: It is subject to the number of read-only instances owned by the source instance. If it is set to `0`, when all read-only nodes are removed, all read requests will be routed to the source instance until at least one of the removed read-only instances rejoins the database proxy to continue processing the read requests.
Adaptive Load Balancing
Choose whether to enable the adaptive load balancing feature. Once it is enabled, requests can be routed to instances with lower load based on backend load conditions to achieve database instance load balancing. For details, see Adaptive Load Balancing.
Connection Pool Status
The connection pool feature mainly mitigates the instance load caused by frequent new connections in non-persistent connection business scenarios. After this option is enabled, you can select the supported connection pool type, which currently can only be the session-level connection pool by default.
Transaction Split
You can set whether to enable this feature. Once enabled, read requests before the first write request in a transaction can be forwarded to read-only instances to reduce the load on the primary instance.
Assign Read Weight
You can select Assigned by system or Custom. If multiple AZs are configured when the database proxy is enabled, you can separately assign the weights of proxy nodes in different AZs.
Note：
The weight here is for read requests (non-transactional).
Unified Weight Management
If the current primary instance has a read-only analysis engine, this feature is supported. Once enabled, the read-only analysis engine can accept query statements forwarded by the proxy in scenarios without hints.
Failover (with Read-Write Attribute being Read/Write Separation)
You can set whether to enable this feature. After it is enabled, if database proxy fails, the database proxy address will route requests to the source instance.
Forwarding Upon Analysis Engine Faults
You can set whether to enable this feature. Once enabled, when the accessed read-only analysis engine fails, requests will be automatically forwarded to other read-only analysis engines based on rules. For detailed fault forwarding policies, see Forwarding Upon Instance Faults.
Apply to Newly Added RO Instances
You can set whether to enable this feature. After it is enabled, a newly purchased read-only instance will be automatically added to the database proxy.
If Assign Read Weight is set to Assigned by system, newly purchased read-only instances will be assigned with the default weight based on their specification.
If Assign Read Weight is set to Custom, when newly purchased read-only instances are added, their weights will be 0 by default, which can be modified by clicking Adjust Configurations in Connection Address on the Database Proxy tab.
Deleting Database Proxy Connection Address
Note:
If your database proxy has multiple connection addresses, you can delete unnecessary ones while keeping the last one.
1. Log in to the TencentDB for MySQL console. In the instance list, click an Instance ID or Manage in the Operation column of the instance with the proxy enabled to enter the instance management page.
2. On the instance management page, find the target address in Database Proxy > Connection Address, and click Close.
