mysqldump with --single-transaction backup still blocks the write

[Lisa Tong]

Hi,

I'd like to set up the online non-blocking backups for innoDB database using mysqldump. I have the binary log enabled.

According to MySQL documentation, we can do online, non-blocking backup by issuing:
mysqldump --single-transaction --flush-logs --master-data=2 --databases test > testdb.sql

But looks like that when it is doing the backup, it still blocks all the write operations. Because inserting data to the table inside the database are blocked and hangs, until the backup is finished.

Any ideas and suggestions?

Thanks,

Lisa