How do I resolve the "Got an error reading communication packets" error in Amazon RDS for MySQL or Aurora MySQL-Compatible?

Short description

You receive the "[Warning] Aborted connection abc to db: 'database name' user: 'user name' host: 'host IP' (Got an error reading communication packets)" error message.

You receive the preceding error message when the either the aborted_clients or the aborted_connects parameter value increases. Amazon RDS cancels the connection and increases the status counter for the aborted_clients parameter when the client dies and doesn't close the connection or the connection drops. The aborted_connects parameter value increases when client fails to connect to the MySQL server. 

If the value of log_error_verbosity exceeds two, then you also receive the error message. The log_error_verbosity parameter specifies the verbosity to manage events that are for the error log. For more information, see Communication errors and aborted connections on the MySQL website.

The following factors might cause the "Got an error reading communication packets" error message:

• Client or driver incompatibility.
• Firewalls or proxies that close any idle connections or block a connection.
• An incorrectly closed client-server connection that results in a higher number of sleeping connections inside Amazon RDS for MySQL.
• A client application that incorrectly terminates a connection.
  Note: MySQL forcefully closes long-running idle connections.
• Idle connections that exceed the wait_timeout or interactive_timeout thresholds.
• A client connection that exceeds the connect_timeout seconds threshold when it gets a connection packet.
• Insufficient values for parameters, such as net_write_timeout and net_read_timeout.
• An exceeded max_allowed_packet parameter value.
  Note: The issue occurs when the value is too small or queries require more memory than you allocate for Amazon RDS for MySQL.

Resolution

Modify timeout parameters

To identify what's causing issue, review the parameters that are related to connectivity timeouts. If you're using default values for your parameter group, then change the default connectivity timeout value for your DB instance.

To change the connectivity parameter, complete the following steps:

1. Open the Amazon RDS console.
2. In the navigation pane, choose Parameter groups.
3. Choose the parameter group for your DB instance.
4. Choose Edit.
5. Search for the connectivity timeout parameter, and then change the value.
   Note: After you change the values, monitor the MySQL error logs when you're testing the new value.

connect_timeout

Set a higher value for connect_timeout to test whether the value reduces the occurrence of this issue. The connect_timeout parameter defines how many seconds the MySQL server DB instance must wait before the DB instance responds with a bad handshake. For more information, see connect_timeout on the MySQL website.

interactive_timeout and wait_timeout

You can also modify interactive_timeout and wait_timeout. For more information about these parameters, see wait_timeout or interactive_timeout on the MySQL website. Applications that use connection pooling, such as Java, must have timeouts that match the connection pool settings.

max_allowed_packet

If the instance must manage large queries, large Binary Large Object (BLOB) columns, or long strings, then increase the value of max_allowed_packet. If a row has more data than the max_allowed_packet value, then you receive an error. For more information, see max_allowed_packet on the MySQL website.

net_write_timeout and net_read_timeout

Increase the net_write_timeout and net_read_timeout values. You can set net_write_timeout and net_read_timeout to the same value as wait_timeout. For more information, see net_write_timeout and net_read_timeout on the MySQL website.

Call the mysql_close() function from the client application to make sure that the Amazon RDS for MySQL or Aurora MySQL-Compatible connections correctly close.

Use other troubleshooting methods

If you still receive the "Got an error reading communications packets" error message, then take any of the following actions:

• Turn on Performance Insights to get the time frame of the SQL statements that encounter issues. For Aurora MySQL-Compatible, see Turning Performance Insights on and off for Aurora.
  Important: Performance Insights will reach its end of life on June 30, 2026. You can upgrade to the Advanced mode of Database insights before June 30, 2026. If you don't upgrade, then DB clusters that use Performance Insights will default to the Standard mode of Database Insights. Only the Advanced mode of Database Insights will support execution plans and on-demand analysis. If your clusters default to the Standard mode, then you might not be able to use these features on the console. To turn on the Advanced mode, see Turning on the Turning on the Advanced mode of Database Insights for Amazon RDS and Turning on the Advanced mode of Database Insights for Amazon Aurora.
• Turn on slow query logs on your Amazon RDS or Aurora MySQL-Compatible DB instance to log queries that run for longer than the long_query_time value.
  Note: The default long_query_time value is 10 seconds.
• Turn on Amazon Virtual Private Cloud (Amazon VPC) Flow Logs to check whether the server or client closed the connection.
• Verify that your application correctly closed the connection from MySQL.
• Run the following tcpdump command from the machine that's running the client to test sample packet captures:

  sudo tcpdump -vvv --interface eth0 port 3306 -W 10 -C 100

Related information

Why did DB connections drop on my Amazon RDS DB instance?

How do I view and download logs for an Aurora Serverless DB cluster?