Bug #111556 Document the change in behavior for start replication until between 57 and 80

• Submitted: 26 Jun 2023 4:14
• Modified: 26 Jun 2023 9:37
• Reporter: Chelluru Vidyadhar
• Status: Verified
• Category: MySQL Server: Documentation
• Severity: S3 (Non-critical)
• Version: 5.7
• OS: Any
• CPU Architecture: Any

[26 Jun 2023 4:14] Chelluru Vidyadhar

Description:
It looks like the START UNTIL FILE, POS syntax will stop both IO_Thread and SQL_Thread in 5.7 version once the mentioned position reached even the documentation (5.7) clearly states its related to only SQL_Thread. 

"The UNTIL clause operates on the replication applier thread (SQL_THREAD option). You can use the SQL_THREAD option or let the replica default to starting both threads. If you use the IO_THREAD option alone, the UNTIL clause is ignored because the applier thread is not started."

https://dev.mysql.com/doc/refman/5.7/en/start-slave.html

In case of 8.0 the same syntax clearly applicable to SQL_thread and stops only SQL Thread when the specified position reached.

How to repeat:
Consider to run START SALVE UNTIL on both MySQL 5.7 and 8.0 versions to see the difference. In 5.7 its stopping both SQL and IO threads and in 8.0 it stops only SQL Thread.

Suggested fix:
Please consider to update the documentation of 5.7 and if possible mention the change in 8.0 documentation as well.

[26 Jun 2023 9:37] MySQL Verification Team

Hello Chelluru,

Thank you for the report and feedback.

regards,
Umesh