ApsaraDB RDS:Configure the connection settings for a database proxy endpoint

Prerequisites

The database proxy feature is enabled. For more information, see Enable the database proxy feature.

Configure the connection settings for a database proxy endpoint

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the left-side navigation pane, click Database Proxy.

3. In the Connection Information section, find the database proxy endpoint for which you want to configure connection settings in the Proxy Endpoint (Terminal) ID column and click Modify Configuration in the Actions column.

4. In the dialog box that appears, modify the related connection settings for the database proxy endpoint based on your business requirements. The following table describes the parameters.

   Parameter	Description
   Connection Description	The custom description of the database proxy endpoint. The description can be up to 30 characters in length.
   Network and Zone	The zone and vSwitch of the database proxy.
   Read/Write Attribute	The read and write attributes of the database proxy endpoint (formerly proxy terminal). Read/Write (Read/Write Splitting): The database proxy endpoint connects to the primary RDS instance and its read-only RDS instances, and can receive write requests. This is the default value. Read-only (Primary Instance Not Connected to Receive Write Requests): The database proxy endpoint connects only to read-only RDS instances and cannot receive write requests. Note After you modify the read and write attributes of a database proxy endpoint, the modification takes effect only for new connections to the database proxy endpoint. Existing connections to the database proxy endpoint remain unchanged. For more information, see Configure the read and write attributes and the read weight of the database proxy and What is read/write splitting? If you use RDS Cluster Edition, you can use the primary and secondary nodes in your RDS cluster to implement read/write splitting.
   Nearest Access	Specifies whether to enable the nearest access feature. We recommend that you enable the nearest access feature to reduce access latency and improve performance. For more information, see Configure the nearest access feature.
   Connection Pooling	The type of the connection pool. For more information, see Configure the connection pooling feature. Transaction-level Connection Pooling: We recommend that you select this option. In most cases, short-lived connections are required in workloads. Connections are frequently established. The number of connections is greater than the maximum number of connections supported by an RDS instance. In the preceding scenarios, if the limits on the transaction-level connection pooling feature do not affect your workloads, we recommend that you select this option. For more information, see Limits of transaction connection pools. Session-level Connection Pooling In most cases, short-lived connections are required in workloads. Connections are frequently established. In the preceding scenarios, if the limits on the transaction-level connection pooling feature affect your workloads, you can select this option instead. For more information, see Limits of transaction connection pools. Disable Connection Pooling: This option is selected by default. In most cases, persistent connections are required in workloads. The number of connections is small. Connection pools such as Druid, DBCP, c3p0, and HikariCP, are used in your applications. In the preceding scenarios, you do not need to use a connection pool. Note If the database proxy version of your RDS instance is earlier than 2.9.1, this parameter is available only when the Read/Write Attribute parameter is set to Read/Write (Read/Write Splitting). If the database proxy version of your RDS instance is 2.9.1 or later, no limits are imposed.
   Latency Threshold	The maximum latency that is allowed for data replication from the primary RDS instance to its read-only RDS instances. Valid values: 0 to 3600. Unit: seconds. The read-only RDS instances may replicate data from the primary RDS instance at a specific latency. The latency varies based on the status of the SQL statements that are executed. We recommend that you set this parameter to a value that is greater than or equal to 30. Note If the database proxy version of your RDS instance is earlier than 2.9.1, you can configure the connection pooling setting only for a database proxy endpoint that is set to read/write. If the database proxy version of your RDS instance is 2.9.1 or later, no limits are imposed. When the latency of data replication to a read-only RDS instance is less than the value of this parameter and the read weight of the read-only RDS instance is not 0, the system forwards read requests to the read-only RDS instance. You can select Disable for this parameter. In this case, read requests are distributed to read-only instances regardless of the latency of the read requests. If you select Read/Write (Read/Write Splitting) for Read/Write Attributes, the value of this parameter is 30 seconds by default. If you select Read-only (Primary Instance Not Connected to Receive Write Requests) for Read/Write Attributes, this parameter is disabled by default.
   Transaction Splitting	The transaction splitting capability. The value is fixed as Enabled. After transaction splitting is enabled, the system forwards the read requests prior to write operations in transactions to the read-only RDS instances. This way, the loads on the primary RDS instance are reduced. Note This parameter appears only when you set the Read/Write Attribute parameter to Read/Write (Read/Write Splitting). For more information, see Use the transaction splitting feature.
   Read Weight Allocation	The method that is used to assign read weights. Automatic Distribution: The system automatically assigns a read weight to each RDS instance in your database system based on the specifications of the RDS instance. After you create a read-only RDS instance, the system automatically assigns a read weight to the read-only RDS instance for the read-only RDS instance to process read requests. Custom: You must specify a read weight for each read-only RDS instance. Valid values: 0 to 10000. The read-only RDS instances process read requests based on the specified read weights. The default read weight of a new read-only RDS instance is 0. You must modify the read weight of the new read-only RDS instance. Note The nearest access feature ensures that requests are forwarded from your application to the database proxy. The read weight configuration ensures that requests are forwarded from the database proxy to the backend databases, which is not affected by the nearest access feature. You must use the two features together to minimize access latency. A higher read weight indicates more read requests that need to be processed. For example, if the primary RDS instance has 3 read-only RDS instances whose read weights are 100, 200, and 200 and the read weight of the primary RDS instance is 0, the primary RDS instance processes only write requests and its read-only RDS instances process read requests at a ratio of 1:2:2. You cannot specify weights for read-only RDS instances whose data replication latencies are specified. For more information, see Set the data replication latency of a read-only ApsaraDB RDS for MySQL instance Configure a data replication latency for a read-only ApsaraDB RDS for MySQL instance After you modify this parameter, the new read weights immediately take effect. The modification does not cause service unavailability. The existing connections also remain valid. Only the requests that are sent over new connections are forwarded based on the new weights. If you use RDS Cluster Edition, the read weights that you specify indicate the read weights of the primary and secondary nodes in the RDS cluster. If you use RDS High-availability Edition, you must create at least one read-only RDS instance before you can specify read weights. For more information about how to configure read and write attributes, see Configure the read and write attributes and the read weight of the database proxy.

5. Click OK.

References

• Enable the database proxy feature

• What is read/write splitting?

• Use a database proxy endpoint to connect to an ApsaraDB RDS for MySQL instance

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