Description of Each IP Address

If you create a TaurusDB instance with one primary node and one read replica, there are up to five different IP addresses.

If you connect your application to a node of the DB instance through a private IP address for read and the node becomes faulty, the IP address cannot be accessed before the fault is rectified.

1. Private IP address for read of the primary node (not recommended)

   After a DB instance is created, the system assigns a private IP address for read to the primary node. If your applications are deployed on a server that is in the same VPC as the DB instance, you can use the IP address to connect to the instance for read and write operations. But if a failover occurs and the primary node becomes a read replica, the IP address can only be used for read operations.

   

2. Private IP address for read of a read replica (not recommended).

   After a DB instance is created, the system assigns a private IP address to the read replica. If your applications are deployed on a server that is in the same VPC as the DB instance, you can use this IP address to connect to the instance for read operations. But if a failover occurs and the read replica is promoted to primary, the IP address can be used for read and write operations.

   

3. Private IP address

   After a DB instance is created, the system assigns a private IP address to the primary node. If your applications are deployed on a server that is in the same VPC as the DB instance, you can use the IP address to connect to the instance for read and write operations. But this IP address is always bound to the primary node. If a failover occurs, the IP address is reassigned to the new primary node, and can then still be used for read and write operations.

   

4. Public IP address (EIP)

   After buying a DB instance and binding an EIP to it, you can connect to the instance over the public network to perform read and write operations. Just like a private IP address, an EIP is always bound to the primary node for read and write operations.

   Figure 1 Viewing the EIP and database port
   

5. Proxy address (available only when you are configuring read/write splitting)

   After buying a DB instance, you can view the proxy address. Connecting to this address allows you to perform both read and write operations. The proxy instance automatically routes write requests to the primary node and read requests to read replicas. This maximizes the multi-node read/write capabilities (one primary node and multiple read replicas), reducing the load on the primary node. Currently, the read/write splitting IP address supports only private network access. Binding an EIP is temporarily not supported.

   

Failover

By default, a TaurusDB instance contains at least two nodes, one primary node (read/write node) and one read replica (read-only node). You can create multiple read replicas if needed.

If the primary node becomes faulty, the system promotes a read replica to primary and demotes the primary node to read replica status.