MySQL rejects a communication packet that exceeds the active max_allowed_packet limit and can close the connection. Large SQL statements, rows containing large binary/text data, and imports can trigger this condition.
- Check the exact database error for
packet too large,max_allowed_packet, or a lost connection during a large query. - Reduce the size of each import batch or SQL statement when the tool supports chunking.
- Compress or split an export only if the import tool can process the resulting parts correctly.
- Do not change unrelated PHP upload limits if the upload succeeds and the failure occurs only after MySQL begins processing the data.
The server-side packet limit may be outside the controls available to a normal hosting account.
