How do I fix the "Lost Connection" error when issuing a query on MySQL?

ERROR 2013 (HY000) at line xx: Lost connection to MySQL server during query

A Lost Connection error occurs when:

  • You have network connectivity issues.
  • Your query is taking too long to complete.

If you are consistently getting this error and queries are taking longer than 30 seconds (the default value for MySQL’s net_read_timeout variable) to complete:

  • Check for network connectivity issues.
  • Revise your query to not send as much data, and therefore be faster.
  • Split your query into multiple smaller queries.
Adjust the sort_buffer_size value while assessing its impact on memory consumption and query performance.
Check for query timeouts and ensure your network connection is stable.
Update backup user permissions, remove the –single-transaction flag, or downgrade mysqldump.