I’m using innobackupex to perform a full backup against a database running MySql 5.6.19. I’ve been performing these backups for a while, but all of a sudden in the middle of the backup both MySQL and the backup will seem to slow to a crawl. Neither process stops completely, but queries against the database become very slow and the log scan positions printed out by the backup start to change very infrequently. I am calling the backup like this:
/usr/bin/innobackupex --compress --no-timestamp --user=XXXX --password=XXXX --no-lock /database_backup/full 2> /var/log/xtrabackup.log
When this happens, attempts to kill the backup or stop mysql both result in a defunct process, and the only way I’ve found to get things running again is to reboot the machine running the database. Based on timestamps of files in the backup directory, it looks like the failure occurs after the files in the root directory of the backup have been created and it has begun copying files into the mysql directory. In particular, /database_backup/full/mysql/innodb_table_stats.ibd.qp is the last file that has been touched.
I’d really appreciate any advice or potential workarounds you can suggest, as we’re running backup-free right now, and that’s no good at all.