AnalyticDB:Connections

FAQ overview

• What do I do if a whitelist configuration error causes a connection failure?

• If the required JDBC connection for a query is closed during the query, is the query terminated on the server?

• If a JDBC connection remains open when the client times out, are the server resources immediately released?

• Why am I unable to use the EasySwoole framework to connect to AnalyticDB for MySQL?

• How do I check the user or client IP address from which burst connections are established?

• What is the maximum number of connections that are allowed for an AnalyticDB for MySQL cluster?

What do I do if a whitelist configuration error causes a connection failure?

No IP address whitelist is configured.

Configure IP address whitelists. For more information, see IP address whitelists.

An incorrect client egress IP address is added to an IP address whitelist.

Client egress IP addresses are used to access external gateways in the local network environment of clients. The client egress IP addresses may not be the on-premises IP addresses of clients. You can use one of the following methods to obtain the correct client egress IP addresses:

• Contact the network administrator of the network environment in which the client is located.

• If you want to connect to AnalyticDB for MySQL in the same virtual private cloud (VPC) over an internal network, the IP address of the Elastic Compute Service (ECS) instance on which the client runs or the CIDR blocks of the VPC must be added to the IP address whitelists.

  Note

  To obtain the CIDR blocks of the VPC, log on to the AnalyticDB for MySQL console and view the VPC ID on the Cluster Information page. Then, log on to the VPC console and find the VPC ID on the VPC page to obtain the CIDR blocks of the VPC.

• If you want to connect to AnalyticDB for MySQL over the Internet, you can obtain the egress IP addresses of the client by using a third-party tool.

  • Enter https://www.ip138.com/ in your browser. The egress IP addresses of the client are displayed on the web page.

  • Run the curl "http://myip.ipip.net" command on the client CLI to obtain the egress IP addresses of the client.

Not all client egress IP addresses are added to IP address whitelists.

• In most cases, a client has more than one egress IP address. If you use a third-party tool to obtain IP addresses, we recommend that you run the curl "http://myip.ipip.net" command several times to obtain all egress IP addresses of the client.

• If you want to add a large number of IP addresses to an IP address whitelist, you can use CIDR blocks that have the 0/24 suffix. For example, you can change 192.168.0.1 to 192.168.0.0/24.

If the required JDBC connection for a query is closed during the query, is the query terminated on the server?

If the query is asynchronously submitted by using the SUBMIT JOB, INSERT INTO SELECT, or CREATE TABLE AS SELECT statement, the query continues. Otherwise, the query is terminated.

If a JDBC connection remains open when the client times out, are the server resources immediately released?

Yes, the server resources are immediately released.

Why am I unable to use the EasySwoole framework to connect to AnalyticDB for MySQL?

This issue occurs because SHOW statements are not supported in PreparedStatement.

How do I check the user or client IP address from which burst connections are established?

Log on to the AnalyticDB for MySQL console. Find the Data Warehouse Edition cluster that you want to manage and click the cluster ID. In the left-side navigation pane, click Diagnostics and Optimization. On the page that appears, click the Connection Information tab to view the Number of User Connections and Number of Connections to Client IP Address parameters.

What is the maximum number of connections that can be established to an AnalyticDB for MySQL cluster?

The number of connections that can be established to an AnalyticDB for MySQL cluster is not limited but varies based on the cluster specifications. We recommend that you establish no more than 50,000 connections to a cluster. Low-specification clusters cannot support excessive connections due to insufficient resources. For more information, see Limits.