Skip to content

docs(clickpipes/mysql): FAQ for binlog event exceeding max_allowed_packet #6379

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dtunikov merged 4 commits into from
Jun 15, 2026
+20 −0
Merged

docs(clickpipes/mysql): FAQ for binlog event exceeding max_allowed_packet #6379

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
222918f
docs(clickpipes/mysql): add FAQ for binlog event exceeding max_allowe…
dtunikov Jun 12, 2026
2970655
docs: specify language for error code fence (MD040)
dtunikov Jun 12, 2026
8ecfb1b
docs: reword max_allowed_packet FAQ heading to drop quoted phrase
dtunikov Jun 12, 2026
5880ab7
suggest to resync if a single row is larger than 1G
dtunikov Jun 15, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions docs/integrations/data-ingestion/clickpipes/mysql/faq.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,26 @@

At the start of an initial load we record the binlog offset to start at. This offset must still be valid when the initial load finishes in order for CDC to progress. If you're ingesting a large amount of data be sure to configure an appropriate binlog retention period. While setting up tables you can speed up initial load by configuring *Use a custom partitioning key for initial load* for large tables under advanced settings so that we can load a single table in parallel.

### Why is my pipe failing with a max_allowed_packet binlog error? {#binlog-event-exceeded-max-allowed-packet}

If your pipe fails with an error similar to:

```text

Check notice on line 32 in docs/integrations/data-ingestion/clickpipes/mysql/faq.md

View workflow job for this annotation

GitHub Actions / vale

ClickHouse.CodeblockFences 

Suggestion: Instead of '```text' for the code block, use yaml, ruby, plaintext, markdown, javascript, shell, go, python, dockerfile, or typescript.
MySQL execute error: ERROR 1236 (HY000): log event entry exceeded max_allowed_packet;
Increase max_allowed_packet on source
```

it means a single binlog event (corresponding to one row change) is larger than your MySQL server's [`max_allowed_packet`](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_max_allowed_packet) setting. Because the server can't send an event that exceeds this limit, the binlog stream read aborts and CDC can't progress.

This is most often caused by rows containing large `BLOB`, `TEXT`, or `JSON` values. To resolve it:

- **Increase `max_allowed_packet` on the source.** Raise it above the size of your largest row change — setting it to the maximum of `1G` is usually safe:
```sql
SET GLOBAL max_allowed_packet = 1073741824; -- 1 GiB
```
Set it in your server configuration (e.g. `my.cnf` or the DB Parameter Group) as well so it persists across restarts.
- **If a single row is larger than 1G:** resync the pipe.

### Why am I getting a TLS certificate validation error when connecting to MySQL? {#tls-certificate-validation-error}

When connecting to MySQL, you may encounter certificate errors like `x509: certificate is not valid for any names` or `x509: certificate signed by unknown authority`. These occur because ClickPipes enables TLS encryption by default.
Expand Down
Loading